fix: parse go-version-file by content

The `parseGoVersionFile` function used to only
check for exact filenames like "go.{mod,work}".
When `go-version-file` pointed to something like a
tools modfile ("go.tool.mod"), it would just dump
the whole file contents back, which then got
mistaken for a version spec and broke the
manifest/dist resolution.

Now it looks at the file content to spot Go module
or workspace files and pulls out the `toolchain`
or `go` directives. Left ".tool-versions" handling
alone.

Fixes #746

Signed-off-by: Dwi Siswanto <git@dw1.io>

__tests__/setup-go.test.ts

@@ -901,6 +901,18 @@ use .
       expect(logSpy).toHaveBeenCalledWith('matching 1.19...');
     });
 
+    it('reads version from go.mod-like file name', async () => {
+      inputs['go-version-file'] = 'go.tool.mod';
+      existsSpy.mockImplementation(() => true);
+      readFileSpy.mockImplementation(() => Buffer.from(goModContents));
+
+      await main.run();
+
+      expect(logSpy).toHaveBeenCalledWith('Setup go version spec 1.14');
+      expect(logSpy).toHaveBeenCalledWith('Attempting to download 1.14...');
+      expect(logSpy).toHaveBeenCalledWith('matching 1.14...');
+    });
+
     it('reads version from .tool-versions', async () => {
       inputs['go-version-file'] = '.tool-versions';
       existsSpy.mockImplementation(() => true);
@@ -1066,6 +1078,19 @@ use .
           expected_version: placeholderVersion,
           desc: 'from go directive when GOTOOLCHAIN is local'
         },
+        {
+          goVersionfile: 'go.tool.mod',
+          fileContents: Buffer.from(buildGoMod(placeholderVersion, version)),
+          expected_version: version,
+          desc: 'from toolchain directive'
+        },
+        {
+          goVersionfile: 'go.tool.mod',
+          fileContents: Buffer.from(buildGoMod(placeholderVersion, version)),
+          gotoolchain_env: 'local',
+          expected_version: placeholderVersion,
+          desc: 'from go directive when GOTOOLCHAIN is local'
+        },
         {
           goVersionfile: 'go.work',
           fileContents: Buffer.from(buildGoMod(placeholderVersion, version)),

dist/setup/index.js

@@ -77493,26 +77493,33 @@ function makeSemver(version) {
     return fullVersion;
 }
 function parseGoVersionFile(versionFilePath) {
+    const moduleOrWorkspaceDirective = /^\s*go\s+(\d+(?:\.\d+)*)/m;
+    const toolchainDirective = /^\s*toolchain\s+go(1\.\d+(?:\.\d+|rc\d+)?)/m;
+    const moduleDeclaration = /^\s*module\s+\S+/m;
+    const workspaceUseDirective = /^\s*use(?:\s+\S+|\s*\()/m;
     const contents = fs_1.default.readFileSync(versionFilePath).toString();
-    if (path.basename(versionFilePath) === 'go.mod' ||
-        path.basename(versionFilePath) === 'go.work') {
+    const fileName = path.basename(versionFilePath);
+    const isGoModOrWorkFileName = fileName === 'go.mod' || fileName === 'go.work';
+    const isGoModuleOrWorkspaceLike = moduleOrWorkspaceDirective.test(contents) &&
+        (moduleDeclaration.test(contents) || workspaceUseDirective.test(contents));
+    if (fileName === '.tool-versions') {
+        const match = contents.match(/^golang\s+([^\n#]+)/m);
+        return match ? match[1].trim() : '';
+    }
+    if (isGoModOrWorkFileName || isGoModuleOrWorkspaceLike) {
         // for backwards compatibility: use version from go directive if
         // 'GOTOOLCHAIN' has been explicitly set
         if (process.env[exports.GOTOOLCHAIN_ENV_VAR] !== exports.GOTOOLCHAIN_LOCAL_VAL) {
             // toolchain directive: https://go.dev/ref/mod#go-mod-file-toolchain
-            const matchToolchain = contents.match(/^toolchain go(1\.\d+(?:\.\d+|rc\d+)?)/m);
+            const matchToolchain = contents.match(toolchainDirective);
             if (matchToolchain) {
                 return matchToolchain[1];
             }
         }
         // go directive: https://go.dev/ref/mod#go-mod-file-go
-        const matchGo = contents.match(/^go (\d+(\.\d+)*)/m);
+        const matchGo = contents.match(moduleOrWorkspaceDirective);
         return matchGo ? matchGo[1] : '';
     }
-    else if (path.basename(versionFilePath) === '.tool-versions') {
-        const match = contents.match(/^golang\s+([^\n#]+)/m);
-        return match ? match[1].trim() : '';
-    }
     return contents.trim();
 }
 function resolveStableVersionDist(versionSpec, arch) {

docs/advanced-usage.md

@@ -164,7 +164,7 @@ jobs:
 
 ## Using the `go-version-file` input
 
-`setup-go` action can read the Go version from a version file. `go-version-file` input is used for specifying the path to the version file. If the file supplied to the `go-version-file` input doesn't exist, the action will fail with an error. This input supports go.mod, go.work, .go-version, and .tool-versions files.
+`setup-go` action can read the Go version from a version file. `go-version-file` input is used for specifying the path to the version file. If the file supplied to the `go-version-file` input doesn't exist, the action will fail with an error. This input supports standard `go.mod` and `go.work` files, custom files that use the same `go.mod`/`go.work` format (for example, `go.tool.mod`), and `.go-version` and `.tool-versions` files.
 
 If both the `go-version` and the `go-version-file` inputs are provided then the `go-version` input is used. The `.tool-versions` file supports version specifications in accordance with asdf standards, adhering to Semantic Versioning ([semver](https://semver.org)).
 

src/installer.ts

@@ -651,30 +651,38 @@ export function makeSemver(version: string): string {
 }
 
 export function parseGoVersionFile(versionFilePath: string): string {
-  const contents = fs.readFileSync(versionFilePath).toString();
+  const moduleOrWorkspaceDirective = /^\s*go\s+(\d+(?:\.\d+)*)/m;
+  const toolchainDirective = /^\s*toolchain\s+go(1\.\d+(?:\.\d+|rc\d+)?)/m;
+  const moduleDeclaration = /^\s*module\s+\S+/m;
+  const workspaceUseDirective = /^\s*use(?:\s+\S+|\s*\()/m;
 
-  if (
-    path.basename(versionFilePath) === 'go.mod' ||
-    path.basename(versionFilePath) === 'go.work'
-  ) {
+  const contents = fs.readFileSync(versionFilePath).toString();
+  const fileName = path.basename(versionFilePath);
+
+  const isGoModOrWorkFileName = fileName === 'go.mod' || fileName === 'go.work';
+  const isGoModuleOrWorkspaceLike =
+    moduleOrWorkspaceDirective.test(contents) &&
+    (moduleDeclaration.test(contents) || workspaceUseDirective.test(contents));
+
+  if (fileName === '.tool-versions') {
+    const match = contents.match(/^golang\s+([^\n#]+)/m);
+    return match ? match[1].trim() : '';
+  }
+
+  if (isGoModOrWorkFileName || isGoModuleOrWorkspaceLike) {
     // for backwards compatibility: use version from go directive if
     // 'GOTOOLCHAIN' has been explicitly set
     if (process.env[GOTOOLCHAIN_ENV_VAR] !== GOTOOLCHAIN_LOCAL_VAL) {
       // toolchain directive: https://go.dev/ref/mod#go-mod-file-toolchain
-      const matchToolchain = contents.match(
-        /^toolchain go(1\.\d+(?:\.\d+|rc\d+)?)/m
-      );
+      const matchToolchain = contents.match(toolchainDirective);
       if (matchToolchain) {
         return matchToolchain[1];
       }
     }
 
     // go directive: https://go.dev/ref/mod#go-mod-file-go
-    const matchGo = contents.match(/^go (\d+(\.\d+)*)/m);
+    const matchGo = contents.match(moduleOrWorkspaceDirective);
     return matchGo ? matchGo[1] : '';
-  } else if (path.basename(versionFilePath) === '.tool-versions') {
-    const match = contents.match(/^golang\s+([^\n#]+)/m);
-    return match ? match[1].trim() : '';
   }
 
   return contents.trim();