Fix bugs related to go_version_file input

action.yml

@@ -53,7 +53,9 @@ inputs:
   go_version:
     description: "the version of Go. By default, the latest version of Go 1.x is installed."
     required: false
-    default: "1.x"
+  go_version_file:
+    description: "Path to the go.mod file or the file containing only Go version."
+    required: false
   cache:
     deprecation: "enable cache"
     default: true

src/main.ts

@@ -31,11 +31,9 @@ async function run() {
     const cwd = path.relative(process.env["GITHUB_WORKSPACE"] || process.cwd(), workdir);
     const enableCache = core.getBooleanInput("cache");
 
-    if (goVersion !== "" || goVersionFile !== "") {
-      await core.group("Installing Go ...", async () => {
-        await setupGo.run(goVersion, goVersionFile);
-      });
-    }
+    await core.group("Installing Go ...", async () => {
+      await setupGo.run(goVersion, goVersionFile);
+    });
 
     const reviewdog = await core.group(
       "🐶 Installing reviewdog ... https://github.com/reviewdog/reviewdog",

src/setup-go/main.ts

@@ -9,6 +9,8 @@ import cp from "child_process";
 import fs from "fs";
 import path from "path";
 
+const defaultGoVersion = "1.x";
+
 export async function run(version: string, versionFilePath: string): Promise<void> {
   try {
     const versionSpec = resolveVersionInput(version, versionFilePath);
@@ -100,5 +102,9 @@ function resolveVersionInput(version: string, versionFilePath: string): string {
     version = installer.parseGoVersionFile(versionFilePath);
   }
 
+  if (!version) {
+    version = defaultGoVersion;
+  }
+
   return version;
 }