diff --git a/.coveragerc b/.coveragerc
index 714aaa1..732613b 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -10,6 +10,8 @@ omit =
     get-git-lfs.py
 
 [report]
+show_missing = True
+skip_covered = True
 exclude_lines =
     # Have to re-enable the standard pragma
     \#\s*pragma: no cover
diff --git a/.gitignore b/.gitignore
index f2bb40f..6fdf044 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,7 +2,7 @@
 *.iml
 *.py[co]
 .*.sw[a-z]
-.cache/
+.cache
 .coverage
 .idea
 .project
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index be99f71..c7f7629 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,5 +1,5 @@
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    sha: v0.8.0
+    sha: v0.9.1
     hooks:
     -   id: trailing-whitespace
     -   id: end-of-file-fixer
@@ -13,16 +13,20 @@
     -   id: requirements-txt-fixer
     -   id: flake8
 -   repo: https://github.com/pre-commit/pre-commit
-    sha: v0.12.2
+    sha: v0.15.2
     hooks:
     -   id: validate_config
     -   id: validate_manifest
 -   repo: https://github.com/asottile/reorder_python_imports
-    sha: v0.3.1
+    sha: v0.3.5
     hooks:
     -   id: reorder-python-imports
         language_version: python2.7
 -   repo: https://github.com/asottile/pyupgrade
-    sha: v1.0.0
+    sha: v1.1.3
     hooks:
     -   id: pyupgrade
+-   repo: https://github.com/asottile/add-trailing-comma
+    sha: v0.5.1
+    hooks:
+    -   id: add-trailing-comma
diff --git a/.pre-commit-hooks.yaml b/.pre-commit-hooks.yaml
index 227abfa..3637ec7 100644
--- a/.pre-commit-hooks.yaml
+++ b/.pre-commit-hooks.yaml
@@ -3,126 +3,194 @@
     description: "Runs autopep8 over python source.  If you configure additional arguments you'll want to at least include -i."
     entry: autopep8-wrapper
     language: python
-    files: \.py$
+    types: [python]
     args: [-i]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-added-large-files
     name: Check for added large files
     description: Prevent giant files from being committed
     entry: check-added-large-files
     language: python
-    # Match all files
+    # for backward compatibility
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-ast
     name: Check python ast
     description: Simply check whether the files parse as valid python.
     entry: check-ast
     language: python
-    files: '\.py$'
+    types: [python]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-byte-order-marker
     name: Check for byte-order marker
     description: Forbid files which have a UTF-8 byte-order marker
     entry: check-byte-order-marker
     language: python
-    files: '\.py$'
+    types: [python]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-case-conflict
     name: Check for case conflicts
     description: Check for files that would conflict in case-insensitive filesystems
     entry: check-case-conflict
     language: python
-    # Match all files
+    # for backward compatibility
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-docstring-first
     name: Check docstring is first
     description: Checks a common error of defining a docstring after code.
     entry: check-docstring-first
     language: python
-    files: \.py$
+    types: [python]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
+-   id: check-executables-have-shebangs
+    name: Check that executables have shebangs
+    description: Ensures that (non-binary) executables have a shebang.
+    entry: check-executables-have-shebangs
+    language: python
+    types: [text, executable]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-json
     name: Check JSON
     description: This hook checks json files for parseable syntax.
     entry: check-json
     language: python
-    files: \.json$
+    types: [json]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: pretty-format-json
     name: Pretty format JSON
     description: This hook sets a standard for formatting JSON files.
     entry: pretty-format-json
     language: python
-    files: \.json$
+    types: [json]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-merge-conflict
     name: Check for merge conflicts
     description: Check for files that contain merge conflict strings.
     entry: check-merge-conflict
     language: python
-    # Match all files
+    types: [text]
+    # for backward compatibility
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-symlinks
     name: Check for broken symlinks
     description: Checks for symlinks which do not point to anything.
     entry: check-symlinks
     language: python
-    # Match all files
+    types: [symlink]
+    # for backward compatibility
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-xml
     name: Check Xml
     description: This hook checks xml files for parseable syntax.
     entry: check-xml
     language: python
-    files: \.xml$
+    types: [xml]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-yaml
     name: Check Yaml
     description: This hook checks yaml files for parseable syntax.
     entry: check-yaml
     language: python
-    files: \.(yaml|yml|eyaml)$
+    types: [yaml]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: debug-statements
     name: Debug Statements (Python)
     description: This hook checks that debug statements (pdb, ipdb, pudb) are not imported on commit.
     entry: debug-statement-hook
     language: python
-    files: \.py$
+    types: [python]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: detect-aws-credentials
     name: Detect AWS Credentials
     description: Detects *your* aws credentials from the aws cli credentials file
     entry: detect-aws-credentials
     language: python
+    types: [text]
+    # for backward compatibility
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: detect-private-key
     name: Detect Private Key
     description: Detects the presence of private keys
     entry: detect-private-key
     language: python
+    types: [text]
+    # for backward compatibility
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: double-quote-string-fixer
     name: Fix double quoted strings
     description: This hook replaces double quoted strings with single quoted strings
     entry: double-quote-string-fixer
     language: python
-    files: \.py$
+    types: [python]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: end-of-file-fixer
     name: Fix End of Files
     description: Ensures that a file is either empty, or ends with one newline.
     entry: end-of-file-fixer
     language: python
-    files: \.(asciidoc|adoc|coffee|cpp|css|c|ejs|erb|groovy|h|haml|hh|hpp|hxx|html|in|j2|jade|json|js|less|markdown|md|ml|mli|pp|py|rb|rs|R|scala|scss|sh|slim|tex|tmpl|ts|txt|yaml|yml)$
+    types: [text]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
+-   id: file-contents-sorter
+    name: File Contents Sorter
+    description: Sort the lines in specified files (defaults to alphabetical). You must provide list of target files as input in your .pre-commit-config.yaml file.
+    entry: file-contents-sorter
+    language: python
+    files: '^$'
 -   id: fix-encoding-pragma
     name: Fix python encoding pragma
     language: python
     entry: fix-encoding-pragma
     description: 'Add # -*- coding: utf-8 -*- to the top of python files'
-    files: \.py$
+    types: [python]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: flake8
     name: Flake8
     description: This hook runs flake8.
     entry: flake8
     language: python
-    files: \.py$
+    types: [python]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: forbid-new-submodules
     name: Forbid new submodules
     language: python
     entry: forbid-new-submodules
     description: Prevent addition of new git submodules
+    # for backward compatibility
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: mixed-line-ending
     name: Mixed line ending
     language: python
@@ -139,23 +207,37 @@
     name: "Don't commit to branch"
     entry: no-commit-to-branch
     language: python
-    files: .*
     always_run: true
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: pyflakes
     name: Pyflakes (DEPRECATED, use flake8)
     description: This hook runs pyflakes. (This is deprecated, use flake8).
     entry: pyflakes
     language: python
-    files: \.py$
+    types: [python]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: requirements-txt-fixer
     name: Fix requirements.txt
     description: Sorts entries in requirements.txt
     entry: requirements-txt-fixer
     language: python
     files: requirements.*\.txt$
+-   id: sort-simple-yaml
+    name: Sort simple YAML files
+    language: python
+    entry: sort-simple-yaml
+    description: Sorts simple YAML files which consist only of top-level keys, preserving comments and blocks.
+    files: '^$'
 -   id: trailing-whitespace
     name: Trim Trailing Whitespace
     description: This hook trims trailing whitespace.
     entry: trailing-whitespace-fixer
     language: python
-    files: \.(asciidoc|adoc|coffee|cpp|css|c|ejs|erb|groovy|h|haml|hh|hpp|hxx|html|in|j2|jade|json|js|less|markdown|md|ml|mli|pp|py|rb|rs|R|scala|scss|sh|slim|tex|tmpl|ts|txt|yaml|yml)$
+    types: [text]
+    # for backward compatibility
+    files: ''
+    minimum_pre_commit_version: 0.15.0
diff --git a/CHANGELOG b/CHANGELOG
index f547531..688ef2b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,17 @@
+0.9.1
+=====
+- Add `check-executables-have-shebangs` hook.
+
+0.9.0
+=====
+- Add `sort-simple-yaml` hook
+- Fix `requirements-txt-fixer` for empty files
+- Add `file-contents-sorter` hook for sorting flat files
+- `check-merge-conflict` now recognizes rebase conflicts
+- Metadata now uses `types` (and therefore requires pre-commit 0.15.0).  This
+  allows the text processing hooks to match *all* text files (and to match
+  files which would only be classifiable by their shebangs).
+
 0.8.0
 =====
 - Add flag allowing missing keys to `detect-aws-credentials`
diff --git a/README.md b/README.md
index 29e0566..33744f6 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ See also: https://github.com/pre-commit/pre-commit
 Add this to your `.pre-commit-config.yaml`
 
     -   repo: git://github.com/pre-commit/pre-commit-hooks
-        sha: v0.8.0  # Use the ref you want to point at
+        sha: v0.9.1  # Use the ref you want to point at
         hooks:
         -   id: trailing-whitespace
         # -   id: ...
@@ -25,7 +25,8 @@ Add this to your `.pre-commit-config.yaml`
 
 - `autopep8-wrapper` - Runs autopep8 over python source.
     - Ignore PEP 8 violation types with `args: ['-i', '--ignore=E000,...']` or
-      through configuration of the `[pep8]` section in setup.cfg / tox.ini.
+      through configuration of the `[pycodestyle]` section in
+      setup.cfg / tox.ini.
 - `check-added-large-files` - Prevent giant files from being committed.
     - Specify what is "too large" with `args: ['--maxkb=123']` (default=500kB).
 - `check-ast` - Simply check whether files parse as valid python.
@@ -34,6 +35,8 @@ Add this to your `.pre-commit-config.yaml`
   case-insensitive filesystem like MacOS HFS+ or Windows FAT.
 - `check-docstring-first` - Checks for a common error of placing code before
   the docstring.
+- `check-executables-have-shebangs` - Checks that non-binary executables have a
+  proper shebang.
 - `check-json` - Attempts to load all json files to verify syntax.
 - `check-merge-conflict` - Check for files that contain merge conflict strings.
 - `check-symlinks` - Checks for symlinks which do not point to anything.
@@ -51,6 +54,7 @@ Add this to your `.pre-commit-config.yaml`
   with single quoted strings.
 - `end-of-file-fixer` - Makes sure files end in a newline and only a newline.
 - `fix-encoding-pragma` - Add `# -*- coding: utf-8 -*-` to the top of python files.
+- `file-contents-sorter` - Sort the lines in specified files (defaults to alphabetical). You must provide list of target files as input to it. Note that this hook WILL remove blank lines and does NOT respect any comments.
     - To remove the coding pragma pass `--remove` (useful in a python3-only codebase)
 - `flake8` - Run flake8 on your python files.
 - `forbid-new-submodules` - Prevent addition of new git submodules.
@@ -72,6 +76,7 @@ Add this to your `.pre-commit-config.yaml`
     - `--no-sort-keys` - when autofixing, retain the original key ordering (instead of sorting the keys)
     - `--top-keys comma,separated,keys` - Keys to keep at the top of mappings.
 - `requirements-txt-fixer` - Sorts entries in requirements.txt
+- `sort-simple-yaml` - Sorts simple YAML files which consist only of top-level keys, preserving comments and blocks.
 - `trailing-whitespace` - Trims trailing whitespace.
     - Markdown linebreak trailing spaces preserved for `.md` and`.markdown`;
       use `args: ['--markdown-linebreak-ext=txt,text']` to add other extensions,
diff --git a/hooks.yaml b/hooks.yaml
index 227abfa..25f71ac 100644
--- a/hooks.yaml
+++ b/hooks.yaml
@@ -1,128 +1,135 @@
 -   id: autopep8-wrapper
-    name: autopep8 wrapper
-    description: "Runs autopep8 over python source.  If you configure additional arguments you'll want to at least include -i."
-    entry: autopep8-wrapper
-    language: python
-    files: \.py$
-    args: [-i]
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-added-large-files
-    name: Check for added large files
-    description: Prevent giant files from being committed
-    entry: check-added-large-files
-    language: python
-    # Match all files
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-ast
-    name: Check python ast
-    description: Simply check whether the files parse as valid python.
-    entry: check-ast
-    language: python
-    files: '\.py$'
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-byte-order-marker
-    name: Check for byte-order marker
-    description: Forbid files which have a UTF-8 byte-order marker
-    entry: check-byte-order-marker
-    language: python
-    files: '\.py$'
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-case-conflict
-    name: Check for case conflicts
-    description: Check for files that would conflict in case-insensitive filesystems
-    entry: check-case-conflict
-    language: python
-    # Match all files
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-docstring-first
-    name: Check docstring is first
-    description: Checks a common error of defining a docstring after code.
-    entry: check-docstring-first
-    language: python
-    files: \.py$
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
+-   id: check-executables-have-shebangs
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-json
-    name: Check JSON
-    description: This hook checks json files for parseable syntax.
-    entry: check-json
-    language: python
-    files: \.json$
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: pretty-format-json
-    name: Pretty format JSON
-    description: This hook sets a standard for formatting JSON files.
-    entry: pretty-format-json
-    language: python
-    files: \.json$
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-merge-conflict
-    name: Check for merge conflicts
-    description: Check for files that contain merge conflict strings.
-    entry: check-merge-conflict
-    language: python
-    # Match all files
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-symlinks
-    name: Check for broken symlinks
-    description: Checks for symlinks which do not point to anything.
-    entry: check-symlinks
-    language: python
-    # Match all files
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-xml
-    name: Check Xml
-    description: This hook checks xml files for parseable syntax.
-    entry: check-xml
-    language: python
-    files: \.xml$
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: check-yaml
-    name: Check Yaml
-    description: This hook checks yaml files for parseable syntax.
-    entry: check-yaml
-    language: python
-    files: \.(yaml|yml|eyaml)$
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: debug-statements
-    name: Debug Statements (Python)
-    description: This hook checks that debug statements (pdb, ipdb, pudb) are not imported on commit.
-    entry: debug-statement-hook
-    language: python
-    files: \.py$
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: detect-aws-credentials
-    name: Detect AWS Credentials
-    description: Detects *your* aws credentials from the aws cli credentials file
-    entry: detect-aws-credentials
-    language: python
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: detect-private-key
-    name: Detect Private Key
-    description: Detects the presence of private keys
-    entry: detect-private-key
-    language: python
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
     files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: double-quote-string-fixer
-    name: Fix double quoted strings
-    description: This hook replaces double quoted strings with single quoted strings
-    entry: double-quote-string-fixer
-    language: python
-    files: \.py$
--   id: end-of-file-fixer
-    name: Fix End of Files
-    description: Ensures that a file is either empty, or ends with one newline.
-    entry: end-of-file-fixer
-    language: python
-    files: \.(asciidoc|adoc|coffee|cpp|css|c|ejs|erb|groovy|h|haml|hh|hpp|hxx|html|in|j2|jade|json|js|less|markdown|md|ml|mli|pp|py|rb|rs|R|scala|scss|sh|slim|tex|tmpl|ts|txt|yaml|yml)$
--   id: fix-encoding-pragma
-    name: Fix python encoding pragma
-    language: python
-    entry: fix-encoding-pragma
-    description: 'Add # -*- coding: utf-8 -*- to the top of python files'
-    files: \.py$
--   id: flake8
-    name: Flake8
-    description: This hook runs flake8.
-    entry: flake8
-    language: python
-    files: \.py$
--   id: forbid-new-submodules
-    name: Forbid new submodules
-    language: python
-    entry: forbid-new-submodules
-    description: Prevent addition of new git submodules
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
     files: ''
+    minimum_pre_commit_version: 0.15.0
+-   id: end-of-file-fixer
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
+-   id: file-contents-sorter
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
+-   id: fix-encoding-pragma
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
+-   id: flake8
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
+-   id: forbid-new-submodules
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: mixed-line-ending
     name: Mixed line ending
     language: python
@@ -130,32 +137,38 @@
     description: Replaces or checks mixed line ending
     files: ''
 -   id: name-tests-test
-    name: Tests should end in _test.py
-    description: This verifies that test files are named correctly
-    entry: name-tests-test
-    language: python
-    files: tests/.+\.py$
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: no-commit-to-branch
-    name: "Don't commit to branch"
-    entry: no-commit-to-branch
-    language: python
-    files: .*
-    always_run: true
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: pyflakes
-    name: Pyflakes (DEPRECATED, use flake8)
-    description: This hook runs pyflakes. (This is deprecated, use flake8).
-    entry: pyflakes
-    language: python
-    files: \.py$
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: requirements-txt-fixer
-    name: Fix requirements.txt
-    description: Sorts entries in requirements.txt
-    entry: requirements-txt-fixer
-    language: python
-    files: requirements.*\.txt$
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
+-   id: sort-simple-yaml
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
 -   id: trailing-whitespace
-    name: Trim Trailing Whitespace
-    description: This hook trims trailing whitespace.
-    entry: trailing-whitespace-fixer
-    language: python
-    files: \.(asciidoc|adoc|coffee|cpp|css|c|ejs|erb|groovy|h|haml|hh|hpp|hxx|html|in|j2|jade|json|js|less|markdown|md|ml|mli|pp|py|rb|rs|R|scala|scss|sh|slim|tex|tmpl|ts|txt|yaml|yml)$
+    language: system
+    name: upgrade-your-pre-commit-version
+    entry: upgrade-your-pre-commit-version
+    files: ''
+    minimum_pre_commit_version: 0.15.0
diff --git a/pre_commit_hooks/check_added_large_files.py b/pre_commit_hooks/check_added_large_files.py
index 8d5f4c4..193b910 100644
--- a/pre_commit_hooks/check_added_large_files.py
+++ b/pre_commit_hooks/check_added_large_files.py
@@ -51,7 +51,7 @@ def main(argv=None):
     parser = argparse.ArgumentParser()
     parser.add_argument(
         'filenames', nargs='*',
-        help='Filenames pre-commit believes are changed.'
+        help='Filenames pre-commit believes are changed.',
     )
     parser.add_argument(
         '--maxkb', type=int, default=500,
diff --git a/pre_commit_hooks/check_ast.py b/pre_commit_hooks/check_ast.py
index 169e077..1090300 100644
--- a/pre_commit_hooks/check_ast.py
+++ b/pre_commit_hooks/check_ast.py
@@ -4,7 +4,7 @@ from __future__ import unicode_literals
 
 import argparse
 import ast
-import os.path
+import platform
 import sys
 import traceback
 
@@ -14,19 +14,19 @@ def check_ast(argv=None):
     parser.add_argument('filenames', nargs='*')
     args = parser.parse_args(argv)
 
-    _, interpreter = os.path.split(sys.executable)
-
     retval = 0
     for filename in args.filenames:
 
         try:
             ast.parse(open(filename, 'rb').read(), filename=filename)
         except SyntaxError:
-            print('{}: failed parsing with {}:'.format(
-                filename, interpreter,
+            print('{}: failed parsing with {} {}:'.format(
+                filename,
+                platform.python_implementation(),
+                sys.version.partition(' ')[0],
             ))
             print('\n{}'.format(
-                '    ' + traceback.format_exc().replace('\n', '\n    ')
+                '    ' + traceback.format_exc().replace('\n', '\n    '),
             ))
             retval = 1
     return retval
diff --git a/pre_commit_hooks/check_case_conflict.py b/pre_commit_hooks/check_case_conflict.py
index 3d6cf74..0f78296 100644
--- a/pre_commit_hooks/check_case_conflict.py
+++ b/pre_commit_hooks/check_case_conflict.py
@@ -45,7 +45,7 @@ def main(argv=None):
     parser = argparse.ArgumentParser()
     parser.add_argument(
         'filenames', nargs='*',
-        help='Filenames pre-commit believes are changed.'
+        help='Filenames pre-commit believes are changed.',
     )
 
     args = parser.parse_args(argv)
diff --git a/pre_commit_hooks/check_docstring_first.py b/pre_commit_hooks/check_docstring_first.py
index 8e658a1..f2f5b72 100644
--- a/pre_commit_hooks/check_docstring_first.py
+++ b/pre_commit_hooks/check_docstring_first.py
@@ -1,4 +1,5 @@
 from __future__ import absolute_import
+from __future__ import print_function
 from __future__ import unicode_literals
 
 import argparse
@@ -30,7 +31,7 @@ def check_docstring_first(src, filename='<unknown>'):
                     '{}:{} Multiple module docstrings '
                     '(first docstring on line {}).'.format(
                         filename, sline, found_docstring_line,
-                    )
+                    ),
                 )
                 return 1
             elif found_code_line is not None:
@@ -38,7 +39,7 @@ def check_docstring_first(src, filename='<unknown>'):
                     '{}:{} Module docstring appears after code '
                     '(code seen on line {}).'.format(
                         filename, sline, found_code_line,
-                    )
+                    ),
                 )
                 return 1
             else:
diff --git a/pre_commit_hooks/check_executables_have_shebangs.py b/pre_commit_hooks/check_executables_have_shebangs.py
new file mode 100644
index 0000000..89ac6e5
--- /dev/null
+++ b/pre_commit_hooks/check_executables_have_shebangs.py
@@ -0,0 +1,40 @@
+"""Check that executable text files have a shebang."""
+from __future__ import absolute_import
+from __future__ import print_function
+from __future__ import unicode_literals
+
+import argparse
+import pipes
+import sys
+
+
+def check_has_shebang(path):
+    with open(path, 'rb') as f:
+        first_bytes = f.read(2)
+
+    if first_bytes != b'#!':
+        print(
+            '{path}: marked executable but has no (or invalid) shebang!\n'
+            "  If it isn't supposed to be executable, try: chmod -x {quoted}\n"
+            '  If it is supposed to be executable, double-check its shebang.'.format(
+                path=path,
+                quoted=pipes.quote(path),
+            ),
+            file=sys.stderr,
+        )
+        return 1
+    else:
+        return 0
+
+
+def main(argv=None):
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('filenames', nargs='*')
+    args = parser.parse_args(argv)
+
+    retv = 0
+
+    for filename in args.filenames:
+        retv |= check_has_shebang(filename)
+
+    return retv
diff --git a/pre_commit_hooks/check_merge_conflict.py b/pre_commit_hooks/check_merge_conflict.py
index d986998..5035b6d 100644
--- a/pre_commit_hooks/check_merge_conflict.py
+++ b/pre_commit_hooks/check_merge_conflict.py
@@ -7,7 +7,7 @@ CONFLICT_PATTERNS = [
     b'<<<<<<< ',
     b'======= ',
     b'=======\n',
-    b'>>>>>>> '
+    b'>>>>>>> ',
 ]
 WARNING_MSG = 'Merge conflict string "{0}" found in {1}:{2}'
 
@@ -15,7 +15,11 @@ WARNING_MSG = 'Merge conflict string "{0}" found in {1}:{2}'
 def is_in_merge():
     return (
         os.path.exists(os.path.join('.git', 'MERGE_MSG')) and
-        os.path.exists(os.path.join('.git', 'MERGE_HEAD'))
+        (
+            os.path.exists(os.path.join('.git', 'MERGE_HEAD')) or
+            os.path.exists(os.path.join('.git', 'rebase-apply')) or
+            os.path.exists(os.path.join('.git', 'rebase-merge'))
+        )
     )
 
 
diff --git a/pre_commit_hooks/debug_statement_hook.py b/pre_commit_hooks/debug_statement_hook.py
index 902198f..d76e6e6 100644
--- a/pre_commit_hooks/debug_statement_hook.py
+++ b/pre_commit_hooks/debug_statement_hook.py
@@ -29,7 +29,7 @@ class ImportStatementParser(ast.NodeVisitor):
     def visit_ImportFrom(self, node):
         if node.module in DEBUG_STATEMENTS:
             self.debug_import_statements.append(
-                DebugStatement(node.module, node.lineno, node.col_offset)
+                DebugStatement(node.module, node.lineno, node.col_offset),
             )
 
 
@@ -52,7 +52,7 @@ def check_file_for_debug_statements(filename):
                     debug_statement.line,
                     debug_statement.col,
                     debug_statement.name,
-                )
+                ),
             )
         return 1
     else:
diff --git a/pre_commit_hooks/detect_aws_credentials.py b/pre_commit_hooks/detect_aws_credentials.py
index 42758f0..b2afd71 100644
--- a/pre_commit_hooks/detect_aws_credentials.py
+++ b/pre_commit_hooks/detect_aws_credentials.py
@@ -12,7 +12,7 @@ def get_aws_credential_files_from_env():
     files = set()
     for env_var in (
         'AWS_CONFIG_FILE', 'AWS_CREDENTIAL_FILE', 'AWS_SHARED_CREDENTIALS_FILE',
-        'BOTO_CONFIG'
+        'BOTO_CONFIG',
     ):
         if env_var in os.environ:
             files.add(os.environ[env_var])
@@ -23,7 +23,7 @@ def get_aws_secrets_from_env():
     """Extract AWS secrets from environment variables."""
     keys = set()
     for env_var in (
-        'AWS_SECRET_ACCESS_KEY', 'AWS_SECURITY_TOKEN', 'AWS_SESSION_TOKEN'
+        'AWS_SECRET_ACCESS_KEY', 'AWS_SECURITY_TOKEN', 'AWS_SESSION_TOKEN',
     ):
         if env_var in os.environ:
             keys.add(os.environ[env_var])
@@ -50,7 +50,7 @@ def get_aws_secrets_from_file(credentials_file):
     for section in parser.sections():
         for var in (
             'aws_secret_access_key', 'aws_security_token',
-            'aws_session_token'
+            'aws_session_token',
         ):
             try:
                 keys.add(parser.get(section, var))
@@ -93,13 +93,13 @@ def main(argv=None):
         help=(
             'Location of additional AWS credential files from which to get '
             'secret keys from'
-        )
+        ),
     )
     parser.add_argument(
         '--allow-missing-credentials',
         dest='allow_missing_credentials',
         action='store_true',
-        help='Allow hook to pass when no credentials are detected.'
+        help='Allow hook to pass when no credentials are detected.',
     )
     args = parser.parse_args(argv)
 
@@ -124,7 +124,7 @@ def main(argv=None):
         print(
             'No AWS keys were found in the configured credential files and '
             'environment variables.\nPlease ensure you have the correct '
-            'setting for --credentials-file'
+            'setting for --credentials-file',
         )
         return 2
 
diff --git a/pre_commit_hooks/file_contents_sorter.py b/pre_commit_hooks/file_contents_sorter.py
new file mode 100644
index 0000000..fe7f7ee
--- /dev/null
+++ b/pre_commit_hooks/file_contents_sorter.py
@@ -0,0 +1,52 @@
+"""
+A very simple pre-commit hook that, when passed one or more filenames
+as arguments, will sort the lines in those files.
+
+An example use case for this: you have a deploy-whitelist.txt file
+in a repo that contains a list of filenames that is used to specify
+files to be included in a docker container. This file has one filename
+per line. Various users are adding/removing lines from this file; using
+this hook on that file should reduce the instances of git merge
+conflicts and keep the file nicely ordered.
+"""
+from __future__ import print_function
+
+import argparse
+
+PASS = 0
+FAIL = 1
+
+
+def sort_file_contents(f):
+    before = list(f)
+    after = sorted([line.strip(b'\n\r') for line in before if line.strip()])
+
+    before_string = b''.join(before)
+    after_string = b'\n'.join(after) + b'\n'
+
+    if before_string == after_string:
+        return PASS
+    else:
+        f.seek(0)
+        f.write(after_string)
+        f.truncate()
+        return FAIL
+
+
+def main(argv=None):
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='+', help='Files to sort')
+    args = parser.parse_args(argv)
+
+    retv = PASS
+
+    for arg in args.filenames:
+        with open(arg, 'rb+') as file_obj:
+            ret_for_file = sort_file_contents(file_obj)
+
+            if ret_for_file:
+                print('Sorting {}'.format(arg))
+
+            retv |= ret_for_file
+
+    return retv
diff --git a/pre_commit_hooks/no_commit_to_branch.py b/pre_commit_hooks/no_commit_to_branch.py
index 4aa3535..22ee95e 100644
--- a/pre_commit_hooks/no_commit_to_branch.py
+++ b/pre_commit_hooks/no_commit_to_branch.py
@@ -15,7 +15,8 @@ def is_on_branch(protected):
 def main(argv=[]):
     parser = argparse.ArgumentParser()
     parser.add_argument(
-        '-b', '--branch', default='master', help='branch to disallow commits to')
+        '-b', '--branch', default='master', help='branch to disallow commits to',
+    )
     args = parser.parse_args(argv)
 
     return int(is_on_branch(args.branch))
diff --git a/pre_commit_hooks/pretty_format_json.py b/pre_commit_hooks/pretty_format_json.py
index 5e04230..bb7a3d0 100644
--- a/pre_commit_hooks/pretty_format_json.py
+++ b/pre_commit_hooks/pretty_format_json.py
@@ -120,7 +120,7 @@ def pretty_format_json(argv=None):
         except simplejson.JSONDecodeError:
             print(
                 "Input File {} is not a valid JSON, consider using check-json"
-                .format(json_file)
+                .format(json_file),
             )
             return 1
 
diff --git a/pre_commit_hooks/requirements_txt_fixer.py b/pre_commit_hooks/requirements_txt_fixer.py
index efa1906..ffabf2a 100644
--- a/pre_commit_hooks/requirements_txt_fixer.py
+++ b/pre_commit_hooks/requirements_txt_fixer.py
@@ -3,6 +3,10 @@ from __future__ import print_function
 import argparse
 
 
+PASS = 0
+FAIL = 1
+
+
 class Requirement(object):
 
     def __init__(self):
@@ -30,21 +34,25 @@ class Requirement(object):
 
 def fix_requirements(f):
     requirements = []
-    before = []
+    before = tuple(f)
     after = []
 
-    for line in f:
-        before.append(line)
+    before_string = b''.join(before)
 
-        # If the most recent requirement object has a value, then it's time to
-        # start building the next requirement object.
+    # If the file is empty (i.e. only whitespace/newlines) exit early
+    if before_string.strip() == b'':
+        return PASS
+
+    for line in before:
+        # If the most recent requirement object has a value, then it's
+        # time to start building the next requirement object.
         if not len(requirements) or requirements[-1].value is not None:
             requirements.append(Requirement())
 
         requirement = requirements[-1]
 
-        # If we see a newline before any requirements, then this is a top of
-        # file comment.
+        # If we see a newline before any requirements, then this is a
+        # top of file comment.
         if len(requirements) == 1 and line.strip() == b'':
             if len(requirement.comments) and requirement.comments[0].startswith(b'#'):
                 requirement.value = b'\n'
@@ -56,20 +64,18 @@ def fix_requirements(f):
             requirement.value = line
 
     for requirement in sorted(requirements):
-        for comment in requirement.comments:
-            after.append(comment)
+        after.extend(requirement.comments)
         after.append(requirement.value)
 
-    before_string = b''.join(before)
     after_string = b''.join(after)
 
     if before_string == after_string:
-        return 0
+        return PASS
     else:
         f.seek(0)
         f.write(after_string)
         f.truncate()
-        return 1
+        return FAIL
 
 
 def fix_requirements_txt(argv=None):
@@ -77,7 +83,7 @@ def fix_requirements_txt(argv=None):
     parser.add_argument('filenames', nargs='*', help='Filenames to fix')
     args = parser.parse_args(argv)
 
-    retv = 0
+    retv = PASS
 
     for arg in args.filenames:
         with open(arg, 'rb+') as file_obj:
diff --git a/pre_commit_hooks/sort_simple_yaml.py b/pre_commit_hooks/sort_simple_yaml.py
new file mode 100755
index 0000000..7afae91
--- /dev/null
+++ b/pre_commit_hooks/sort_simple_yaml.py
@@ -0,0 +1,123 @@
+#!/usr/bin/env python
+"""Sort a simple YAML file, keeping blocks of comments and definitions
+together.
+
+We assume a strict subset of YAML that looks like:
+
+    # block of header comments
+    # here that should always
+    # be at the top of the file
+
+    # optional comments
+    # can go here
+    key: value
+    key: value
+
+    key: value
+
+In other words, we don't sort deeper than the top layer, and might corrupt
+complicated YAML files.
+"""
+from __future__ import print_function
+
+import argparse
+
+
+QUOTES = ["'", '"']
+
+
+def sort(lines):
+    """Sort a YAML file in alphabetical order, keeping blocks together.
+
+    :param lines: array of strings (without newlines)
+    :return: sorted array of strings
+    """
+    # make a copy of lines since we will clobber it
+    lines = list(lines)
+    new_lines = parse_block(lines, header=True)
+
+    for block in sorted(parse_blocks(lines), key=first_key):
+        if new_lines:
+            new_lines.append('')
+        new_lines.extend(block)
+
+    return new_lines
+
+
+def parse_block(lines, header=False):
+    """Parse and return a single block, popping off the start of `lines`.
+
+    If parsing a header block, we stop after we reach a line that is not a
+    comment. Otherwise, we stop after reaching an empty line.
+
+    :param lines: list of lines
+    :param header: whether we are parsing a header block
+    :return: list of lines that form the single block
+    """
+    block_lines = []
+    while lines and lines[0] and (not header or lines[0].startswith('#')):
+        block_lines.append(lines.pop(0))
+    return block_lines
+
+
+def parse_blocks(lines):
+    """Parse and return all possible blocks, popping off the start of `lines`.
+
+    :param lines: list of lines
+    :return: list of blocks, where each block is a list of lines
+    """
+    blocks = []
+
+    while lines:
+        if lines[0] == '':
+            lines.pop(0)
+        else:
+            blocks.append(parse_block(lines))
+
+    return blocks
+
+
+def first_key(lines):
+    """Returns a string representing the sort key of a block.
+
+    The sort key is the first YAML key we encounter, ignoring comments, and
+    stripping leading quotes.
+
+    >>> print(test)
+    # some comment
+    'foo': true
+    >>> first_key(test)
+    'foo'
+    """
+    for line in lines:
+        if line.startswith('#'):
+            continue
+        if any(line.startswith(quote) for quote in QUOTES):
+            return line[1:]
+        return line
+
+
+def main(argv=None):
+    parser = argparse.ArgumentParser()
+    parser.add_argument('filenames', nargs='*', help='Filenames to fix')
+    args = parser.parse_args(argv)
+
+    retval = 0
+
+    for filename in args.filenames:
+        with open(filename, 'r+') as f:
+            lines = [line.rstrip() for line in f.readlines()]
+            new_lines = sort(lines)
+
+            if lines != new_lines:
+                print("Fixing file `{filename}`".format(filename=filename))
+                f.seek(0)
+                f.write("\n".join(new_lines) + "\n")
+                f.truncate()
+                retval = 1
+
+    return retval
+
+
+if __name__ == '__main__':
+    exit(main())
diff --git a/pre_commit_hooks/tests_should_end_in_test.py b/pre_commit_hooks/tests_should_end_in_test.py
index 5f9bbac..9bea20d 100644
--- a/pre_commit_hooks/tests_should_end_in_test.py
+++ b/pre_commit_hooks/tests_should_end_in_test.py
@@ -11,7 +11,7 @@ def validate_files(argv=None):
     parser.add_argument('filenames', nargs='*')
     parser.add_argument(
         '--django', default=False, action='store_true',
-        help='Use Django-style test naming pattern (test*.py)'
+        help='Use Django-style test naming pattern (test*.py)',
     )
     args = parser.parse_args(argv)
 
@@ -27,8 +27,8 @@ def validate_files(argv=None):
             retcode = 1
             print(
                 '{} does not match pattern "{}"'.format(
-                    filename, test_name_pattern
-                )
+                    filename, test_name_pattern,
+                ),
             )
 
     return retcode
diff --git a/pre_commit_hooks/trailing_whitespace_fixer.py b/pre_commit_hooks/trailing_whitespace_fixer.py
index 1ae15a9..d44750d 100644
--- a/pre_commit_hooks/trailing_whitespace_fixer.py
+++ b/pre_commit_hooks/trailing_whitespace_fixer.py
@@ -36,7 +36,7 @@ def fix_trailing_whitespace(argv=None):
         const=[],
         default=argparse.SUPPRESS,
         dest='markdown_linebreak_ext',
-        help='Do not preserve linebreak spaces in Markdown'
+        help='Do not preserve linebreak spaces in Markdown',
     )
     parser.add_argument(
         '--markdown-linebreak-ext',
@@ -45,7 +45,7 @@ def fix_trailing_whitespace(argv=None):
         default=['md,markdown'],
         metavar='*|EXT[,EXT,...]',
         nargs='?',
-        help='Markdown extensions (or *) for linebreak spaces'
+        help='Markdown extensions (or *) for linebreak spaces',
     )
     parser.add_argument('filenames', nargs='*', help='Filenames to fix')
     args = parser.parse_args(argv)
@@ -69,7 +69,7 @@ def fix_trailing_whitespace(argv=None):
             parser.error(
                 "bad --markdown-linebreak-ext extension '{}' (has . / \\ :)\n"
                 "  (probably filename; use '--markdown-linebreak-ext=EXT')"
-                .format(ext)
+                .format(ext),
             )
 
     return_code = 0
diff --git a/setup.py b/setup.py
index d7bde34..55dee45 100644
--- a/setup.py
+++ b/setup.py
@@ -6,7 +6,7 @@ setup(
     name='pre_commit_hooks',
     description='Some out-of-the-box hooks for pre-commit.',
     url='https://github.com/pre-commit/pre-commit-hooks',
-    version='0.8.0',
+    version='0.9.1',
 
     author='Anthony Sottile',
     author_email='asottile@umich.edu',
@@ -24,9 +24,9 @@ setup(
 
     packages=find_packages(exclude=('tests*', 'testing*')),
     install_requires=[
-        # quickfix to prevent pep8 conflicts
+        # quickfix to prevent pycodestyle conflicts
         'flake8!=2.5.3',
-        'autopep8>=1.1',
+        'autopep8>=1.3',
         'pyyaml',
         'simplejson',
         'six',
@@ -39,6 +39,7 @@ setup(
             'check-byte-order-marker = pre_commit_hooks.check_byte_order_marker:main',
             'check-case-conflict = pre_commit_hooks.check_case_conflict:main',
             'check-docstring-first = pre_commit_hooks.check_docstring_first:main',
+            'check-executables-have-shebangs = pre_commit_hooks.check_executables_have_shebangs:main',
             'check-json = pre_commit_hooks.check_json:check_json',
             'check-merge-conflict = pre_commit_hooks.check_merge_conflict:detect_merge_conflict',
             'check-symlinks = pre_commit_hooks.check_symlinks:check_symlinks',
@@ -49,6 +50,7 @@ setup(
             'detect-private-key = pre_commit_hooks.detect_private_key:detect_private_key',
             'double-quote-string-fixer = pre_commit_hooks.string_fixer:main',
             'end-of-file-fixer = pre_commit_hooks.end_of_file_fixer:end_of_file_fixer',
+            'file-contents-sorter = pre_commit_hooks.file_contents_sorter:main',
             'fix-encoding-pragma = pre_commit_hooks.fix_encoding_pragma:main',
             'forbid-new-submodules = pre_commit_hooks.forbid_new_submodules:main',
             'mixed-line-ending = pre_commit_hooks.mixed_line_ending:mixed_line_ending',
@@ -56,6 +58,7 @@ setup(
             'no-commit-to-branch = pre_commit_hooks.no_commit_to_branch:main',
             'pretty-format-json = pre_commit_hooks.pretty_format_json:pretty_format_json',
             'requirements-txt-fixer = pre_commit_hooks.requirements_txt_fixer:fix_requirements_txt',
+            'sort-simple-yaml = pre_commit_hooks.sort_simple_yaml:main',
             'trailing-whitespace-fixer = pre_commit_hooks.trailing_whitespace_fixer:fix_trailing_whitespace',
         ],
     },
diff --git a/testing/resources/aws_config_with_multiple_sections.ini b/testing/resources/aws_config_with_multiple_sections.ini
index ca6a8a3..2053b9a 100644
--- a/testing/resources/aws_config_with_multiple_sections.ini
+++ b/testing/resources/aws_config_with_multiple_sections.ini
@@ -9,4 +9,4 @@ aws_secret_access_key = z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb
 aws_access_key_id = AKIAJIMMINYCRICKET0A
 aws_secret_access_key = ixswosj8gz3wuik405jl9k3vdajsnxfhnpui38ez
 [test]
-aws_session_token = foo
\ No newline at end of file
+aws_session_token = foo
diff --git a/testing/resources/aws_config_with_secret_and_session_token.ini b/testing/resources/aws_config_with_secret_and_session_token.ini
index 4bd675d..4496765 100644
--- a/testing/resources/aws_config_with_secret_and_session_token.ini
+++ b/testing/resources/aws_config_with_secret_and_session_token.ini
@@ -2,4 +2,4 @@
 [production]
 aws_access_key_id = AKIAVOGONSVOGONS0042
 aws_secret_access_key = z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb
-aws_session_token = foo
\ No newline at end of file
+aws_session_token = foo
diff --git a/testing/resources/aws_config_with_session_token.ini b/testing/resources/aws_config_with_session_token.ini
index e07f2ac..b03f127 100644
--- a/testing/resources/aws_config_with_session_token.ini
+++ b/testing/resources/aws_config_with_session_token.ini
@@ -1,3 +1,3 @@
 # file with an AWS session token
 [production]
-aws_session_token = foo
\ No newline at end of file
+aws_session_token = foo
diff --git a/tests/autopep8_wrapper_test.py b/tests/autopep8_wrapper_test.py
index 5eb4df2..780752c 100644
--- a/tests/autopep8_wrapper_test.py
+++ b/tests/autopep8_wrapper_test.py
@@ -23,6 +23,6 @@ def test_main_failing(tmpdir, input_src, expected_ret, output_src):
 
 def test_respects_config_file(tmpdir):
     with tmpdir.as_cwd():
-        tmpdir.join('setup.cfg').write('[pep8]\nignore=E221')
+        tmpdir.join('setup.cfg').write('[pycodestyle]\nignore=E221')
         tmpdir.join('test.py').write('print(1    + 2)\n')
         assert main(['test.py', '-i', '-v']) == 0
diff --git a/tests/check_added_large_files_test.py b/tests/check_added_large_files_test.py
index ce15f5c..4a84463 100644
--- a/tests/check_added_large_files_test.py
+++ b/tests/check_added_large_files_test.py
@@ -81,12 +81,7 @@ def test_allows_gitlfs(temp_git_dir):  # pragma: no cover
     with temp_git_dir.as_cwd():
         # Work around https://github.com/github/git-lfs/issues/913
         cmd_output(
-            'git',
-            'commit',
-            '--no-gpg-sign',
-            '--allow-empty',
-            '-m',
-            'foo',
+            'git', 'commit', '--no-gpg-sign', '--allow-empty', '-m', 'foo',
         )
         cmd_output('git', 'lfs', 'install')
         temp_git_dir.join('f.py').write('a' * 10000)
diff --git a/tests/check_docstring_first_test.py b/tests/check_docstring_first_test.py
index f14880b..aa9898d 100644
--- a/tests/check_docstring_first_test.py
+++ b/tests/check_docstring_first_test.py
@@ -19,7 +19,7 @@ TESTS = (
         '"foo"\n',
         1,
         '{filename}:2 Module docstring appears after code '
-        '(code seen on line 1).\n'
+        '(code seen on line 1).\n',
     ),
     # Test double docstring
     (
@@ -28,7 +28,7 @@ TESTS = (
         '"fake docstring"\n',
         1,
         '{filename}:3 Multiple module docstrings '
-        '(first docstring on line 1).\n'
+        '(first docstring on line 1).\n',
     ),
     # Test multiple lines of code above
     (
diff --git a/tests/check_executables_have_shebangs_test.py b/tests/check_executables_have_shebangs_test.py
new file mode 100644
index 0000000..0cb9dcf
--- /dev/null
+++ b/tests/check_executables_have_shebangs_test.py
@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+import pytest
+
+from pre_commit_hooks.check_executables_have_shebangs import main
+
+
+@pytest.mark.parametrize(
+    'content', (
+        b'#!/bin/bash\nhello world\n',
+        b'#!/usr/bin/env python3.6',
+        b'#!python',
+        '#!☃'.encode('UTF-8'),
+    ),
+)
+def test_has_shebang(content, tmpdir):
+    path = tmpdir.join('path')
+    path.write(content, 'wb')
+    assert main((path.strpath,)) == 0
+
+
+@pytest.mark.parametrize(
+    'content', (
+        b'',
+        b' #!python\n',
+        b'\n#!python\n',
+        b'python\n',
+        '☃'.encode('UTF-8'),
+
+    ),
+)
+def test_bad_shebang(content, tmpdir, capsys):
+    path = tmpdir.join('path')
+    path.write(content, 'wb')
+    assert main((path.strpath,)) == 1
+    _, stderr = capsys.readouterr()
+    assert stderr.startswith('{}: marked executable but'.format(path.strpath))
diff --git a/tests/check_json_test.py b/tests/check_json_test.py
index 996bfbb..6ba26c1 100644
--- a/tests/check_json_test.py
+++ b/tests/check_json_test.py
@@ -4,11 +4,13 @@ from pre_commit_hooks.check_json import check_json
 from testing.util import get_resource_path
 
 
-@pytest.mark.parametrize(('filename', 'expected_retval'), (
-    ('bad_json.notjson', 1),
-    ('bad_json_latin1.nonjson', 1),
-    ('ok_json.json', 0),
-))
+@pytest.mark.parametrize(
+    ('filename', 'expected_retval'), (
+        ('bad_json.notjson', 1),
+        ('bad_json_latin1.nonjson', 1),
+        ('ok_json.json', 0),
+    ),
+)
 def test_check_json(capsys, filename, expected_retval):
     ret = check_json([get_resource_path(filename)])
     assert ret == expected_retval
diff --git a/tests/check_merge_conflict_test.py b/tests/check_merge_conflict_test.py
index f1528b2..a999aca 100644
--- a/tests/check_merge_conflict_test.py
+++ b/tests/check_merge_conflict_test.py
@@ -45,7 +45,7 @@ def f1_is_a_conflict_file(tmpdir):
             'child\n'
             '=======\n'
             'parent\n'
-            '>>>>>>>'
+            '>>>>>>>',
         ) or f1.startswith(
             '<<<<<<< HEAD\n'
             'child\n'
@@ -53,7 +53,15 @@ def f1_is_a_conflict_file(tmpdir):
             '||||||| merged common ancestors\n'
             '=======\n'
             'parent\n'
-            '>>>>>>>'
+            '>>>>>>>',
+        ) or f1.startswith(
+            # .gitconfig with [pull] rebase = preserve causes a rebase which
+            # flips parent / child
+            '<<<<<<< HEAD\n'
+            'parent\n'
+            '=======\n'
+            'child\n'
+            '>>>>>>>',
         )
         assert os.path.exists(os.path.join('.git', 'MERGE_MSG'))
         yield
@@ -85,7 +93,7 @@ def repository_is_pending_merge(tmpdir):
         repo2_f2.write('child\n')
         cmd_output('git', 'add', '--', repo2_f2.strpath)
         cmd_output('git', 'commit', '--no-gpg-sign', '-m', 'clone commit2')
-        cmd_output('git', 'pull', '--no-commit')
+        cmd_output('git', 'pull', '--no-commit', '--no-rebase')
         # We should end up in a pending merge
         assert repo2_f1.read() == 'parent\n'
         assert repo2_f2.read() == 'child\n'
diff --git a/tests/check_symlinks_test.py b/tests/check_symlinks_test.py
index 4b11e71..19bb5b4 100644
--- a/tests/check_symlinks_test.py
+++ b/tests/check_symlinks_test.py
@@ -7,10 +7,12 @@ from testing.util import get_resource_path
 
 
 @pytest.mark.xfail(os.name == 'nt', reason='No symlink support on windows')
-@pytest.mark.parametrize(('filename', 'expected_retval'), (
-    ('broken_symlink', 1),
-    ('working_symlink', 0),
-))
+@pytest.mark.parametrize(
+    ('filename', 'expected_retval'), (
+        ('broken_symlink', 1),
+        ('working_symlink', 0),
+    ),
+)
 def test_check_symlinks(filename, expected_retval):
     ret = check_symlinks([get_resource_path(filename)])
     assert ret == expected_retval
diff --git a/tests/check_xml_test.py b/tests/check_xml_test.py
index 99b0902..84e365d 100644
--- a/tests/check_xml_test.py
+++ b/tests/check_xml_test.py
@@ -4,10 +4,12 @@ from pre_commit_hooks.check_xml import check_xml
 from testing.util import get_resource_path
 
 
-@pytest.mark.parametrize(('filename', 'expected_retval'), (
-    ('bad_xml.notxml', 1),
-    ('ok_xml.xml', 0),
-))
+@pytest.mark.parametrize(
+    ('filename', 'expected_retval'), (
+        ('bad_xml.notxml', 1),
+        ('ok_xml.xml', 0),
+    ),
+)
 def test_check_xml(filename, expected_retval):
     ret = check_xml([get_resource_path(filename)])
     assert ret == expected_retval
diff --git a/tests/check_yaml_test.py b/tests/check_yaml_test.py
index c145fdc..73d6593 100644
--- a/tests/check_yaml_test.py
+++ b/tests/check_yaml_test.py
@@ -4,10 +4,12 @@ from pre_commit_hooks.check_yaml import check_yaml
 from testing.util import get_resource_path
 
 
-@pytest.mark.parametrize(('filename', 'expected_retval'), (
-    ('bad_yaml.notyaml', 1),
-    ('ok_yaml.yaml', 0),
-))
+@pytest.mark.parametrize(
+    ('filename', 'expected_retval'), (
+        ('bad_yaml.notyaml', 1),
+        ('ok_yaml.yaml', 0),
+    ),
+)
 def test_check_yaml(filename, expected_retval):
     ret = check_yaml([get_resource_path(filename)])
     assert ret == expected_retval
diff --git a/tests/debug_statement_hook_test.py b/tests/debug_statement_hook_test.py
index c318346..6d8d7d8 100644
--- a/tests/debug_statement_hook_test.py
+++ b/tests/debug_statement_hook_test.py
@@ -10,30 +10,36 @@ from testing.util import get_resource_path
 
 @pytest.fixture
 def ast_with_no_debug_imports():
-    return ast.parse("""
+    return ast.parse(
+        """
 import foo
 import bar
 import baz
 from foo import bar
-""")
+""",
+    )
 
 
 @pytest.fixture
 def ast_with_debug_import_form_1():
-    return ast.parse("""
+    return ast.parse(
+        """
 
 import ipdb; ipdb.set_trace()
 
-""")
+""",
+    )
 
 
 @pytest.fixture
 def ast_with_debug_import_form_2():
-    return ast.parse("""
+    return ast.parse(
+        """
 
 from pudb import set_trace; set_trace()
 
-""")
+""",
+    )
 
 
 def test_returns_no_debug_statements(ast_with_no_debug_imports):
@@ -46,7 +52,7 @@ def test_returns_one_form_1(ast_with_debug_import_form_1):
     visitor = ImportStatementParser()
     visitor.visit(ast_with_debug_import_form_1)
     assert visitor.debug_import_statements == [
-        DebugStatement('ipdb', 3, 0)
+        DebugStatement('ipdb', 3, 0),
     ]
 
 
@@ -54,7 +60,7 @@ def test_returns_one_form_2(ast_with_debug_import_form_2):
     visitor = ImportStatementParser()
     visitor.visit(ast_with_debug_import_form_2)
     assert visitor.debug_import_statements == [
-        DebugStatement('pudb', 3, 0)
+        DebugStatement('pudb', 3, 0),
     ]
 
 
diff --git a/tests/detect_aws_credentials_test.py b/tests/detect_aws_credentials_test.py
index 943a3f8..954f3d8 100644
--- a/tests/detect_aws_credentials_test.py
+++ b/tests/detect_aws_credentials_test.py
@@ -21,16 +21,16 @@ from testing.util import get_resource_path
         (
             {
                 'AWS_DUMMY_KEY': '/foo', 'AWS_CONFIG_FILE': '/bar',
-                'AWS_CREDENTIAL_FILE': '/baz'
+                'AWS_CREDENTIAL_FILE': '/baz',
             },
-            {'/bar', '/baz'}
+            {'/bar', '/baz'},
         ),
         (
             {
                 'AWS_CONFIG_FILE': '/foo', 'AWS_CREDENTIAL_FILE': '/bar',
-                'AWS_SHARED_CREDENTIALS_FILE': '/baz'
+                'AWS_SHARED_CREDENTIALS_FILE': '/baz',
             },
-            {'/foo', '/bar', '/baz'}
+            {'/foo', '/bar', '/baz'},
         ),
     ),
 )
@@ -51,7 +51,7 @@ def test_get_aws_credentials_file_from_env(env_vars, values):
         ({'AWS_DUMMY_KEY': 'foo', 'AWS_SECRET_ACCESS_KEY': 'bar'}, {'bar'}),
         (
             {'AWS_SECRET_ACCESS_KEY': 'foo', 'AWS_SECURITY_TOKEN': 'bar'},
-            {'foo', 'bar'}
+            {'foo', 'bar'},
         ),
     ),
 )
@@ -66,19 +66,21 @@ def test_get_aws_secrets_from_env(env_vars, values):
     (
         (
             'aws_config_with_secret.ini',
-            {'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb'}
+            {'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb'},
         ),
         ('aws_config_with_session_token.ini', {'foo'}),
-        ('aws_config_with_secret_and_session_token.ini',
-         {'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb', 'foo'}),
+        (
+            'aws_config_with_secret_and_session_token.ini',
+            {'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb', 'foo'},
+        ),
         (
             'aws_config_with_multiple_sections.ini',
             {
                 '7xebzorgm5143ouge9gvepxb2z70bsb2rtrh099e',
                 'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb',
                 'ixswosj8gz3wuik405jl9k3vdajsnxfhnpui38ez',
-                'foo'
-            }
+                'foo',
+            },
         ),
         ('aws_config_without_secrets.ini', set()),
         ('nonsense.txt', set()),
@@ -121,7 +123,7 @@ def test_non_existent_credentials(mock_secrets_env, mock_secrets_file, capsys):
     mock_secrets_file.return_value = set()
     ret = main((
         get_resource_path('aws_config_without_secrets.ini'),
-        "--credentials-file=testing/resources/credentailsfilethatdoesntexist"
+        "--credentials-file=testing/resources/credentailsfilethatdoesntexist",
     ))
     assert ret == 2
     out, _ = capsys.readouterr()
@@ -141,6 +143,6 @@ def test_non_existent_credentials_with_allow_flag(mock_secrets_env, mock_secrets
     ret = main((
         get_resource_path('aws_config_without_secrets.ini'),
         "--credentials-file=testing/resources/credentailsfilethatdoesntexist",
-        "--allow-missing-credentials"
+        "--allow-missing-credentials",
     ))
     assert ret == 0
diff --git a/tests/file_contents_sorter_test.py b/tests/file_contents_sorter_test.py
new file mode 100644
index 0000000..1f9a14b
--- /dev/null
+++ b/tests/file_contents_sorter_test.py
@@ -0,0 +1,33 @@
+import pytest
+
+from pre_commit_hooks.file_contents_sorter import FAIL
+from pre_commit_hooks.file_contents_sorter import main
+from pre_commit_hooks.file_contents_sorter import PASS
+
+
+@pytest.mark.parametrize(
+    ('input_s', 'expected_retval', 'output'),
+    (
+        (b'', FAIL, b'\n'),
+        (b'lonesome\n', PASS, b'lonesome\n'),
+        (b'missing_newline', FAIL, b'missing_newline\n'),
+        (b'newline\nmissing', FAIL, b'missing\nnewline\n'),
+        (b'missing\nnewline', FAIL, b'missing\nnewline\n'),
+        (b'alpha\nbeta\n', PASS, b'alpha\nbeta\n'),
+        (b'beta\nalpha\n', FAIL, b'alpha\nbeta\n'),
+        (b'C\nc\n', PASS, b'C\nc\n'),
+        (b'c\nC\n', FAIL, b'C\nc\n'),
+        (b'mag ical \n tre vor\n', FAIL, b' tre vor\nmag ical \n'),
+        (b'@\n-\n_\n#\n', FAIL, b'#\n-\n@\n_\n'),
+        (b'extra\n\n\nwhitespace\n', FAIL, b'extra\nwhitespace\n'),
+        (b'whitespace\n\n\nextra\n', FAIL, b'extra\nwhitespace\n'),
+    ),
+)
+def test_integration(input_s, expected_retval, output, tmpdir):
+    path = tmpdir.join('file.txt')
+    path.write_binary(input_s)
+
+    output_retval = main([path.strpath])
+
+    assert path.read_binary() == output
+    assert output_retval == expected_retval
diff --git a/tests/fix_encoding_pragma_test.py b/tests/fix_encoding_pragma_test.py
index d49f1ba..7288bfa 100644
--- a/tests/fix_encoding_pragma_test.py
+++ b/tests/fix_encoding_pragma_test.py
@@ -56,7 +56,7 @@ def test_integration_remove_ok(tmpdir):
             b'# -*- coding: utf-8 -*-\n'
             b'foo = "bar"\n'
         ),
-    )
+    ),
 )
 def test_ok_inputs(input_str):
     bytesio = io.BytesIO(input_str)
@@ -100,7 +100,7 @@ def test_ok_inputs(input_str):
         (b'#!/usr/bin/env python\n', b''),
         (b'#!/usr/bin/env python\n#coding: utf8\n', b''),
         (b'#!/usr/bin/env python\n# -*- coding: utf-8 -*-\n', b''),
-    )
+    ),
 )
 def test_not_ok_inputs(input_str, output):
     bytesio = io.BytesIO(input_str)
diff --git a/tests/forbid_new_submodules_test.py b/tests/forbid_new_submodules_test.py
index 1750e00..fb37862 100644
--- a/tests/forbid_new_submodules_test.py
+++ b/tests/forbid_new_submodules_test.py
@@ -10,10 +10,14 @@ from pre_commit_hooks.forbid_new_submodules import main
 def git_dir_with_git_dir(tmpdir):
     with tmpdir.as_cwd():
         cmd_output('git', 'init', '.')
-        cmd_output('git', 'commit', '-m', 'init', '--allow-empty')
+        cmd_output(
+            'git', 'commit', '-m', 'init', '--allow-empty', '--no-gpg-sign',
+        )
         cmd_output('git', 'init', 'foo')
-        with tmpdir.join('foo').as_cwd():
-            cmd_output('git', 'commit', '-m', 'init', '--allow-empty')
+        cmd_output(
+            'git', 'commit', '-m', 'init', '--allow-empty', '--no-gpg-sign',
+            cwd=tmpdir.join('foo').strpath,
+        )
         yield
 
 
diff --git a/tests/meta_test.py b/tests/meta_test.py
index 202b3d7..29e06a8 100644
--- a/tests/meta_test.py
+++ b/tests/meta_test.py
@@ -1,7 +1,43 @@
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
 import io
 
+import yaml
 
-def test_hooks_yaml_same_contents():
-    legacy_contents = io.open('hooks.yaml').read()
-    contents = io.open('.pre-commit-hooks.yaml').read()
-    assert legacy_contents == contents
+
+def _assert_parseable_in_old_pre_commit(hooks):
+    for hook in hooks:
+        assert {'id', 'name', 'entry', 'files', 'language'} <= set(hook)
+
+
+def test_legacy_hooks():
+    with io.open('hooks.yaml') as legacy_file:
+        legacy = yaml.load(legacy_file.read())
+    with io.open('.pre-commit-hooks.yaml') as hooks_file:
+        hooks = yaml.load(hooks_file.read())
+
+    # The same set of hooks should be defined in both files
+    new_hook_ids = {hook['id'] for hook in hooks}
+    legacy_hook_ids = {hook['id'] for hook in legacy}
+    assert new_hook_ids == legacy_hook_ids
+
+    # Both files should be parseable by pre-commit<0.15.0
+    _assert_parseable_in_old_pre_commit(legacy)
+    _assert_parseable_in_old_pre_commit(hooks)
+
+    # The legacy file should force upgrading
+    for hook in legacy:
+        del hook['id']
+        assert hook == {
+            'language': 'system',
+            'name': 'upgrade-your-pre-commit-version',
+            'entry': 'upgrade-your-pre-commit-version',
+            'files': '',
+            'minimum_pre_commit_version': '0.15.0',
+        }
+
+    # Each hook should require a new version if it uses types
+    for hook in hooks:
+        if 'types' in hook:
+            assert hook['minimum_pre_commit_version'] == '0.15.0'
diff --git a/tests/pretty_format_json_test.py b/tests/pretty_format_json_test.py
index 62e37f1..eeef65b 100644
--- a/tests/pretty_format_json_test.py
+++ b/tests/pretty_format_json_test.py
@@ -17,35 +17,41 @@ def test_parse_indent():
         parse_indent('-2')
 
 
-@pytest.mark.parametrize(('filename', 'expected_retval'), (
-    ('not_pretty_formatted_json.json', 1),
-    ('unsorted_pretty_formatted_json.json', 1),
-    ('non_ascii_pretty_formatted_json.json', 1),
-    ('pretty_formatted_json.json', 0),
-))
+@pytest.mark.parametrize(
+    ('filename', 'expected_retval'), (
+        ('not_pretty_formatted_json.json', 1),
+        ('unsorted_pretty_formatted_json.json', 1),
+        ('non_ascii_pretty_formatted_json.json', 1),
+        ('pretty_formatted_json.json', 0),
+    ),
+)
 def test_pretty_format_json(filename, expected_retval):
     ret = pretty_format_json([get_resource_path(filename)])
     assert ret == expected_retval
 
 
-@pytest.mark.parametrize(('filename', 'expected_retval'), (
-    ('not_pretty_formatted_json.json', 1),
-    ('unsorted_pretty_formatted_json.json', 0),
-    ('non_ascii_pretty_formatted_json.json', 1),
-    ('pretty_formatted_json.json', 0),
-))
+@pytest.mark.parametrize(
+    ('filename', 'expected_retval'), (
+        ('not_pretty_formatted_json.json', 1),
+        ('unsorted_pretty_formatted_json.json', 0),
+        ('non_ascii_pretty_formatted_json.json', 1),
+        ('pretty_formatted_json.json', 0),
+    ),
+)
 def test_unsorted_pretty_format_json(filename, expected_retval):
     ret = pretty_format_json(['--no-sort-keys', get_resource_path(filename)])
     assert ret == expected_retval
 
 
-@pytest.mark.parametrize(('filename', 'expected_retval'), (
-    ('not_pretty_formatted_json.json', 1),
-    ('unsorted_pretty_formatted_json.json', 1),
-    ('non_ascii_pretty_formatted_json.json', 1),
-    ('pretty_formatted_json.json', 1),
-    ('tab_pretty_formatted_json.json', 0),
-))
+@pytest.mark.parametrize(
+    ('filename', 'expected_retval'), (
+        ('not_pretty_formatted_json.json', 1),
+        ('unsorted_pretty_formatted_json.json', 1),
+        ('non_ascii_pretty_formatted_json.json', 1),
+        ('pretty_formatted_json.json', 1),
+        ('tab_pretty_formatted_json.json', 0),
+    ),
+)
 def test_tab_pretty_format_json(filename, expected_retval):
     ret = pretty_format_json(['--indent', '\t', get_resource_path(filename)])
     assert ret == expected_retval
diff --git a/tests/requirements_txt_fixer_test.py b/tests/requirements_txt_fixer_test.py
index 1c590a5..dcf7a76 100644
--- a/tests/requirements_txt_fixer_test.py
+++ b/tests/requirements_txt_fixer_test.py
@@ -1,31 +1,41 @@
 import pytest
 
+from pre_commit_hooks.requirements_txt_fixer import FAIL
 from pre_commit_hooks.requirements_txt_fixer import fix_requirements_txt
+from pre_commit_hooks.requirements_txt_fixer import PASS
 from pre_commit_hooks.requirements_txt_fixer import Requirement
 
-# Input, expected return value, expected output
-TESTS = (
-    (b'foo\nbar\n', 1, b'bar\nfoo\n'),
-    (b'bar\nfoo\n', 0, b'bar\nfoo\n'),
-    (b'#comment1\nfoo\n#comment2\nbar\n', 1, b'#comment2\nbar\n#comment1\nfoo\n'),
-    (b'#comment1\nbar\n#comment2\nfoo\n', 0, b'#comment1\nbar\n#comment2\nfoo\n'),
-    (b'#comment\n\nfoo\nbar\n', 1, b'#comment\n\nbar\nfoo\n'),
-    (b'#comment\n\nbar\nfoo\n', 0, b'#comment\n\nbar\nfoo\n'),
-    (b'\nfoo\nbar\n', 1, b'bar\n\nfoo\n'),
-    (b'\nbar\nfoo\n', 0, b'\nbar\nfoo\n'),
-    (b'pyramid==1\npyramid-foo==2\n', 0, b'pyramid==1\npyramid-foo==2\n'),
-    (b'ocflib\nDjango\nPyMySQL\n', 1, b'Django\nocflib\nPyMySQL\n'),
-    (b'-e git+ssh://git_url@tag#egg=ocflib\nDjango\nPyMySQL\n', 1, b'Django\n-e git+ssh://git_url@tag#egg=ocflib\nPyMySQL\n'),
+
+@pytest.mark.parametrize(
+    ('input_s', 'expected_retval', 'output'),
+    (
+        (b'', PASS, b''),
+        (b'\n', PASS, b'\n'),
+        (b'foo\nbar\n', FAIL, b'bar\nfoo\n'),
+        (b'bar\nfoo\n', PASS, b'bar\nfoo\n'),
+        (b'#comment1\nfoo\n#comment2\nbar\n', FAIL, b'#comment2\nbar\n#comment1\nfoo\n'),
+        (b'#comment1\nbar\n#comment2\nfoo\n', PASS, b'#comment1\nbar\n#comment2\nfoo\n'),
+        (b'#comment\n\nfoo\nbar\n', FAIL, b'#comment\n\nbar\nfoo\n'),
+        (b'#comment\n\nbar\nfoo\n', PASS, b'#comment\n\nbar\nfoo\n'),
+        (b'\nfoo\nbar\n', FAIL, b'bar\n\nfoo\n'),
+        (b'\nbar\nfoo\n', PASS, b'\nbar\nfoo\n'),
+        (b'pyramid==1\npyramid-foo==2\n', PASS, b'pyramid==1\npyramid-foo==2\n'),
+        (b'ocflib\nDjango\nPyMySQL\n', FAIL, b'Django\nocflib\nPyMySQL\n'),
+        (
+            b'-e git+ssh://git_url@tag#egg=ocflib\nDjango\nPyMySQL\n',
+            FAIL,
+            b'Django\n-e git+ssh://git_url@tag#egg=ocflib\nPyMySQL\n',
+        ),
+    ),
 )
-
-
-@pytest.mark.parametrize(('input_s', 'expected_retval', 'output'), TESTS)
 def test_integration(input_s, expected_retval, output, tmpdir):
     path = tmpdir.join('file.txt')
     path.write_binary(input_s)
 
-    assert fix_requirements_txt([path.strpath]) == expected_retval
+    output_retval = fix_requirements_txt([path.strpath])
+
     assert path.read_binary() == output
+    assert output_retval == expected_retval
 
 
 def test_requirement_object():
diff --git a/tests/sort_simple_yaml_test.py b/tests/sort_simple_yaml_test.py
new file mode 100644
index 0000000..176d12f
--- /dev/null
+++ b/tests/sort_simple_yaml_test.py
@@ -0,0 +1,120 @@
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+import os
+
+import pytest
+
+from pre_commit_hooks.sort_simple_yaml import first_key
+from pre_commit_hooks.sort_simple_yaml import main
+from pre_commit_hooks.sort_simple_yaml import parse_block
+from pre_commit_hooks.sort_simple_yaml import parse_blocks
+from pre_commit_hooks.sort_simple_yaml import sort
+
+RETVAL_GOOD = 0
+RETVAL_BAD = 1
+TEST_SORTS = [
+    (
+        ['c: true', '', 'b: 42', 'a: 19'],
+        ['b: 42', 'a: 19', '', 'c: true'],
+        RETVAL_BAD,
+    ),
+
+    (
+        ['# i am', '# a header', '', 'c: true', '', 'b: 42', 'a: 19'],
+        ['# i am', '# a header', '', 'b: 42', 'a: 19', '', 'c: true'],
+        RETVAL_BAD,
+    ),
+
+    (
+        ['# i am', '# a header', '', 'already: sorted', '', 'yup: i am'],
+        ['# i am', '# a header', '', 'already: sorted', '', 'yup: i am'],
+        RETVAL_GOOD,
+    ),
+
+    (
+        ['# i am', '# a header'],
+        ['# i am', '# a header'],
+        RETVAL_GOOD,
+    ),
+]
+
+
+@pytest.mark.parametrize('bad_lines,good_lines,retval', TEST_SORTS)
+def test_integration_good_bad_lines(tmpdir, bad_lines, good_lines, retval):
+    file_path = os.path.join(tmpdir.strpath, 'foo.yaml')
+
+    with open(file_path, 'w') as f:
+        f.write("\n".join(bad_lines) + "\n")
+
+    assert main([file_path]) == retval
+
+    with open(file_path, 'r') as f:
+        assert [line.rstrip() for line in f.readlines()] == good_lines
+
+
+def test_parse_header():
+    lines = ['# some header', '# is here', '', 'this is not a header']
+    assert parse_block(lines, header=True) == ['# some header', '# is here']
+    assert lines == ['', 'this is not a header']
+
+    lines = ['this is not a header']
+    assert parse_block(lines, header=True) == []
+    assert lines == ['this is not a header']
+
+
+def test_parse_block():
+    # a normal block
+    lines = ['a: 42', 'b: 17', '', 'c: 19']
+    assert parse_block(lines) == ['a: 42', 'b: 17']
+    assert lines == ['', 'c: 19']
+
+    # a block at the end
+    lines = ['c: 19']
+    assert parse_block(lines) == ['c: 19']
+    assert lines == []
+
+    # no block
+    lines = []
+    assert parse_block(lines) == []
+    assert lines == []
+
+
+def test_parse_blocks():
+    # normal blocks
+    lines = ['a: 42', 'b: 17', '', 'c: 19']
+    assert parse_blocks(lines) == [['a: 42', 'b: 17'], ['c: 19']]
+    assert lines == []
+
+    # a single block
+    lines = ['a: 42', 'b: 17']
+    assert parse_blocks(lines) == [['a: 42', 'b: 17']]
+    assert lines == []
+
+    # no blocks
+    lines = []
+    assert parse_blocks(lines) == []
+    assert lines == []
+
+
+def test_first_key():
+    # first line
+    lines = ['a: 42', 'b: 17', '', 'c: 19']
+    assert first_key(lines) == 'a: 42'
+
+    # second line
+    lines = ['# some comment', 'a: 42', 'b: 17', '', 'c: 19']
+    assert first_key(lines) == 'a: 42'
+
+    # second line with quotes
+    lines = ['# some comment', '"a": 42', 'b: 17', '', 'c: 19']
+    assert first_key(lines) == 'a": 42'
+
+    # no lines
+    lines = []
+    assert first_key(lines) is None
+
+
+@pytest.mark.parametrize('bad_lines,good_lines,_', TEST_SORTS)
+def test_sort(bad_lines, good_lines, _):
+    assert sort(bad_lines) == good_lines
diff --git a/tests/string_fixer_test.py b/tests/string_fixer_test.py
index 0429b95..a65213b 100644
--- a/tests/string_fixer_test.py
+++ b/tests/string_fixer_test.py
@@ -22,16 +22,20 @@ TESTS = (
     # Docstring
     ('""" Foo """', '""" Foo """', 0),
     (
-        textwrap.dedent("""
+        textwrap.dedent(
+            """
         x = " \\
         foo \\
         "\n
-        """),
-        textwrap.dedent("""
+        """,
+        ),
+        textwrap.dedent(
+            """
         x = ' \\
         foo \\
         '\n
-        """),
+        """,
+        ),
         1,
     ),
     ('"foo""bar"', "'foo''bar'", 1),
diff --git a/tests/trailing_whitespace_fixer_test.py b/tests/trailing_whitespace_fixer_test.py
index eb2a1d0..a771e67 100644
--- a/tests/trailing_whitespace_fixer_test.py
+++ b/tests/trailing_whitespace_fixer_test.py
@@ -69,7 +69,7 @@ def test_markdown_linebreak_ext_opt(filename, input_s, output, tmpdir):
     path = tmpdir.join(filename)
     path.write(input_s)
     ret = fix_trailing_whitespace((
-        '--markdown-linebreak-ext=TxT', path.strpath
+        '--markdown-linebreak-ext=TxT', path.strpath,
     ))
     assert ret == 1
     assert path.read() == output
diff --git a/tox.ini b/tox.ini
index bf2eba2..d0863eb 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,7 @@
 [tox]
 project = pre_commit_hooks
 # These should match the travis env list
-envlist = py27,py34,py35,pypy
+envlist = py27,py35,py36,pypy
 
 [testenv]
 deps = -rrequirements-dev.txt
@@ -14,7 +14,7 @@ setenv =
 commands =
     coverage erase
     coverage run -m pytest {posargs:tests}
-    coverage report --show-missing --fail-under 100
+    coverage report --fail-under 100
     pre-commit install -f --install-hooks
     pre-commit run --all-files