add tests for yaml scanning

pkg/resource/files.go

@@ -87,21 +87,16 @@ func findFilesInFolders(ctx context.Context, paths []string, ignoreFilePatterns
 	return files, errors
 }
 
-func findResourcesInFile(p string, resources chan<- Resource, errors chan<- error, buf []byte) {
+func findResourcesInReader(p string, f io.Reader, resources chan<- Resource, errors chan<- error, buf []byte) {
-	f, err := os.Open(p)
-	defer f.Close()
-	if err != nil {
-		errors <- DiscoveryError{p, err}
-		return
-	}
-
 	scanner := bufio.NewScanner(f)
 	scanner.Buffer(buf, len(buf))
 	scanner.Split(SplitYAMLDocument)
 	nRes := 0
 	for res := scanner.Scan(); res != false; res = scanner.Scan() {
-		resources <- Resource{Path: p, Bytes: []byte(scanner.Text())}
+		if len(scanner.Text()) > 0 {
-		nRes++
+			resources <- Resource{Path: p, Bytes: []byte(scanner.Text())}
+			nRes++
+		}
 	}
 	if err := scanner.Err(); err != nil {
 		errors <- DiscoveryError{p, err}
@@ -111,6 +106,18 @@ func findResourcesInFile(p string, resources chan<- Resource, errors chan<- erro
 	}
 }
 
+func findResourcesInFile(p string, resources chan<- Resource, errors chan<- error, buf []byte) {
+	f, err := os.Open(p)
+	defer f.Close()
+
+	if err != nil {
+		errors <- DiscoveryError{p, err}
+		return
+	}
+
+	findResourcesInReader(p, f, resources, errors, buf)
+}
+
 func FromFiles(ctx context.Context, paths []string, ignoreFilePatterns []string) (<-chan Resource, <-chan error) {
 	resources := make(chan Resource)
 

pkg/resource/files_test.go

@@ -2,6 +2,8 @@ package resource
 
 import (
 	"os"
+	"strings"
+	"sync"
 	"testing"
 	"time"
 )
@@ -87,3 +89,116 @@ func TestIsJSONFile(t *testing.T) {
 		}
 	}
 }
+
+func TestFindResourcesInReader(t *testing.T) {
+	maxResourceSize := 4 * 1024 * 1024   // 4MB ought to be enough for everybody
+	buf := make([]byte, maxResourceSize) // We reuse this to avoid multiple large memory allocations
+
+	for i, testCase := range []struct {
+		filePath string
+		yamlData string
+		res      []Resource
+		errs     []error
+	}{
+		{
+			"manifest.yaml",
+			``,
+			[]Resource{
+				{
+					Path:  "manifest.yaml",
+					Bytes: nil,
+					sig:   nil,
+				},
+			},
+			nil,
+		},
+		{
+			"manifest.yaml",
+			`---
+foo: bar
+`,
+			[]Resource{
+				{
+					Path:  "manifest.yaml",
+					Bytes: []byte("---\nfoo: bar\n"),
+					sig:   nil,
+				},
+			},
+			nil,
+		},
+		{
+			"manifest.yaml",
+			`---
+foo: bar
+---
+lorem: ipsum
+`,
+			[]Resource{
+				{
+					Path:  "manifest.yaml",
+					Bytes: []byte("---\nfoo: bar"),
+					sig:   nil,
+				},
+				{
+					Path:  "manifest.yaml",
+					Bytes: []byte("lorem: ipsum\n"),
+					sig:   nil,
+				},
+			},
+			nil,
+		},
+	} {
+		res := make(chan Resource)
+		errs := make(chan error)
+		receivedResources := []Resource{}
+		receivedErrs := []error{}
+		var wg sync.WaitGroup
+		wg.Add(1)
+
+		go func() {
+			for {
+				select {
+				case receivedResource, ok := <-res:
+					if ok {
+						receivedResources = append(receivedResources, receivedResource)
+						continue
+					}
+					res = nil
+
+				case receivedErr, ok := <-errs:
+					if ok {
+						receivedErrs = append(receivedErrs, receivedErr)
+						continue
+					}
+					errs = nil
+				}
+
+				if res == nil && errs == nil {
+					break
+				}
+			}
+			wg.Done()
+		}()
+
+		r := strings.NewReader(testCase.yamlData)
+		findResourcesInReader(testCase.filePath, r, res, errs, buf)
+		close(res)
+		close(errs)
+		wg.Wait()
+
+		if len(receivedResources) != len(testCase.res) {
+			t.Errorf("test %d: expected %d resources, received %d: %+v", i, len(testCase.res), len(receivedResources), receivedResources)
+			continue
+		}
+
+		for j, r := range receivedResources {
+			if r.Path != testCase.res[j].Path {
+				t.Errorf("test %d, resource %d, expected path %s, received %s", i, j, testCase.res[j].Path, r.Path)
+			}
+
+			if string(r.Bytes) != string(testCase.res[j].Bytes) {
+				t.Errorf("test %d, resource %d, expected Bytes %s, received %s", i, j, string(testCase.res[j].Bytes), string(r.Bytes))
+			}
+		}
+	}
+}