feat: add version-file input

You can now use .tool-versions file to specify GoReleaser version to download

src/context.ts

@@ -7,6 +7,7 @@ export const osArch: string = os.arch();
 export interface Inputs {
   distribution: string;
   version: string;
+  versionFile: string;
   args: string;
   workdir: string;
   installOnly: boolean;
@@ -15,7 +16,8 @@ export interface Inputs {
 export async function getInputs(): Promise<Inputs> {
   return {
     distribution: core.getInput('distribution') || 'goreleaser',
-    version: core.getInput('version') || '~> v2',
+    version: core.getInput('version'),
+    versionFile: core.getInput('version-file'),
     args: core.getInput('args'),
     workdir: core.getInput('workdir') || '.',
     installOnly: core.getBooleanInput('install-only')

src/main.ts

@@ -6,12 +6,14 @@ import * as context from './context';
 import * as goreleaser from './goreleaser';
 import * as core from '@actions/core';
 import * as exec from '@actions/exec';
+import {getRequestedVersion} from './version';
 
 async function run(): Promise<void> {
   try {
     const inputs: context.Inputs = await context.getInputs();
-    const bin = await goreleaser.install(inputs.distribution, inputs.version);
-    core.info(`GoReleaser ${inputs.version} installed successfully`);
+    const version = getRequestedVersion(inputs);
+    const bin = await goreleaser.install(inputs.distribution, version);
+    core.info(`GoReleaser ${version} installed successfully`);
 
     if (inputs.installOnly) {
       const goreleaserDir = path.dirname(bin);

src/version.ts

@@ -0,0 +1,41 @@
+import * as core from '@actions/core';
+import * as fs from 'fs';
+import path from 'path';
+import {Inputs} from './context';
+
+export function getRequestedVersion(inputs: Inputs): string {
+  let requestedVersion = inputs.version;
+  let versionFilePath = inputs.versionFile;
+
+  if (requestedVersion && versionFilePath) {
+    core.warning(
+      `Both version (${requestedVersion}) and version-file (${versionFilePath}) inputs are specified, only version will be used`
+    );
+  }
+
+  if (requestedVersion == '' && versionFilePath) {
+    const workingDirectory = inputs.workdir;
+    if (workingDirectory) {
+      versionFilePath = path.join(workingDirectory, versionFilePath);
+    }
+
+    if (!fs.existsSync(versionFilePath)) {
+      throw new Error(`The specified GoReleaser version file at: ${versionFilePath} does not exist`);
+    }
+
+    const content = fs.readFileSync(versionFilePath, 'utf-8');
+
+    if (path.basename(versionFilePath) === '.tool-versions') {
+      // asdf/mise file.
+      const match = content.match(/^goreleaser\s+([^\n#]+)/m);
+      requestedVersion = match ? 'v' + match[1].trim().replace(/^v/gi, '') : '';
+    }
+  }
+
+  if (!requestedVersion) {
+    // default to latest v2 release
+    requestedVersion = '~> v2';
+  }
+
+  return requestedVersion;
+}