Add support for rc and beta versions in go.mod file

The regex in `parseGoVersionFile()` didn't consider rc and beta
versions. The regex has been extended.

In `findMatch()` the match is checked using `semver.satisfies()`. But
`semver.satisfies()` doesn't no about Go's non-semver rc and beta
version formats (1.16c1 instead of 1.16.0-rc.1).

We cannot use `makeSemver()` on `versionSpec` and compare the result
using `semver.satisfies()` because `versionSpec` coulb be, well, a
spec. Instead we forst check if there is a strict match between the
candidate version and `makeSemver(versionSpec)`.

Fixes #525.

Author: arnested

__tests__/setup-go.test.ts

@@ -265,6 +265,19 @@ describe('setup-go', () => {
     expect(fileName).toBe('go1.14rc1.linux-amd64.tar.gz');
   });
 
+  it('finds unstable pre-release version (go version format)', async () => {
+    os.platform = 'linux';
+    os.arch = 'x64';
+
+    // spec: 1.14rc1, stable=false => go1.14rc1
+    const match: im.IGoVersion | undefined = await im.findMatch('1.14rc1');
+    expect(match).toBeDefined();
+    const version: string = match ? match.version : '';
+    expect(version).toBe('go1.14rc1');
+    const fileName = match ? match.files[0].filename : '';
+    expect(fileName).toBe('go1.14rc1.linux-amd64.tar.gz');
+  });
+
   it('evaluates to stable with input as true', async () => {
     inputs['go-version'] = '1.13.0';
     inputs.stable = 'true';

dist/setup/index.js

@@ -94763,7 +94763,8 @@ function findMatch(versionSpec_1) {
             const candidate = candidates[i];
             const version = makeSemver(candidate.version);
             core.debug(`check ${version} satisfies ${versionSpec}`);
-            if (semver.satisfies(version, versionSpec)) {
+            if (version === makeSemver(versionSpec) ||
+                semver.satisfies(version, versionSpec)) {
                 goFile = candidate.files.find(file => {
                     core.debug(`${file.arch}===${archFilter} && ${file.os}===${platFilter}`);
                     return file.arch === archFilter && file.os === platFilter;
@@ -94831,7 +94832,7 @@ function parseGoVersionFile(versionFilePath) {
             }
         }
         // go directive: https://go.dev/ref/mod#go-mod-file-go
-        const matchGo = contents.match(/^go (\d+(\.\d+)*)/m);
+        const matchGo = contents.match(/^go (\d+(\.\d+)*(?:\.\d+|(beta|rc)\d+)?)/m);
         return matchGo ? matchGo[1] : '';
     }
     else if (path.basename(versionFilePath) === '.tool-versions') {

src/installer.ts

@@ -423,7 +423,10 @@ export async function findMatch(
     const version = makeSemver(candidate.version);
 
     core.debug(`check ${version} satisfies ${versionSpec}`);
-    if (semver.satisfies(version, versionSpec)) {
+    if (
+      version === makeSemver(versionSpec) ||
+      semver.satisfies(version, versionSpec)
+    ) {
       goFile = candidate.files.find(file => {
         core.debug(
           `${file.arch}===${archFilter} && ${file.os}===${platFilter}`
@@ -511,7 +514,7 @@ export function parseGoVersionFile(versionFilePath: string): string {
     }
 
     // go directive: https://go.dev/ref/mod#go-mod-file-go
-    const matchGo = contents.match(/^go (\d+(\.\d+)*)/m);
+    const matchGo = contents.match(/^go (\d+(\.\d+)*(?:\.\d+|(beta|rc)\d+)?)/m);
     return matchGo ? matchGo[1] : '';
   } else if (path.basename(versionFilePath) === '.tool-versions') {
     const match = contents.match(/^golang\s+([^\n#]+)/m);