feat: rewrite format handling

README.md

@@ -10,6 +10,7 @@ The action runs [golangci-lint](https://github.com/golangci/golangci-lint) and r
 
 ## Compatibility
 
+* `v6.0.0+` removes `annotations` option.
 * `v5.0.0+` removes `skip-pkg-cache` and `skip-build-cache` because the cache related to Go itself is already handled by `actions/setup-go`.
 * `v4.0.0+` requires an explicit `actions/setup-go` installation step before using this action: `uses: actions/setup-go@v5`.
   The `skip-go-installation` option has been removed.
@@ -212,23 +213,24 @@ with:
 
 If set the number is `<= 0`, the cache will be always invalidate (Not recommended).
 
-### `annotations`
+### `problem-matchers`
 
 (optional)
 
-To enable/disable GitHub Action annotations.
+Force the usage of the embedded problem matchers.
 
-If disabled (`false`), the output format(s) will follow the golangci-lint configuration file (or CLI flags from `args`) 
-and use the same default as golangci-lint (i.e. `colored-line-number`).
+By default, the [problem matcher of Go (`actions/setup-go`)](https://github.com/actions/setup-go/blob/main/matchers.json) already handles the golangci-lint output (`colored-line-number`). 
+
+Works only with `colored-line-number` (the golangci-lint default).
 
 https://golangci-lint.run/usage/configuration/#output-configuration
 
-The default value is `true`.
+The default value is `false`.
 
 ```yml
 uses: golangci/golangci-lint-action@v5
 with:
-  annotations: false
+  problem-matchers: true
   # ...
 ```
 

action.yml

@@ -36,9 +36,9 @@ inputs:
       restore existing caches, subject to other options.
     default: 'false'
     required: false
-  annotations:
-    description: "To Enable/disable GitHub Action annotations"
-    default: 'true'
+  problem-matchers:
+    description: "Force the usage of the embedded problem matchers"
+    default: 'false'
     required: false
   args:
     description: "golangci-lint command line arguments"

problem-matchers.json

@@ -0,0 +1,17 @@
+{
+  "problemMatcher": [
+    {
+      "owner": "golangci-lint-colored-line-number",
+      "severity": "error",
+      "pattern": [
+        {
+          "regexp": "^([^:]+):(\\d+):(?:(\\d+):)?\\s+(.+ \\(.+\\))$",
+          "file": 1,
+          "line": 2,
+          "column": 3,
+          "message": 4
+        }
+      ]
+    }
+  ]
+}

src/run.ts

@@ -185,21 +185,32 @@ async function runLint(lintPath: string, patchPath: string): Promise<void> {
   const userArgsMap = new Map<string, string>(userArgsList)
   const userArgNames = new Set<string>(userArgsList.map(([key]) => key))
 
-  const annotations = core.getBooleanInput(`annotations`)
+  const problemMatchers = core.getBooleanInput(`problem-matchers`)
+
+  if (problemMatchers) {
+    const matchersPath = path.join(__dirname, "../..", "problem-matchers.json")
+    if (fs.existsSync(matchersPath)) {
+      // Adds problem matchers.
+      // https://github.com/actions/setup-go/blob/cdcb36043654635271a94b9a6d1392de5bb323a7/src/main.ts#L81-L83
+      core.info(`##[add-matcher]${matchersPath}`)
+    }
+  }
 
-  if (annotations) {
-    const formats = (userArgsMap.get("out-format") || "")
-      .trim()
-      .split(",")
-      .filter((f) => f.length > 0)
-      .filter((f) => !f.startsWith(`github-actions`))
-      .concat("github-actions")
-      .join(",")
+  const formats = (userArgsMap.get("out-format") || "")
+    .trim()
+    .split(",")
+    .filter((f) => f.length > 0)
+    .filter((f) => !f.startsWith(`github-actions`)) // Removes `github-actions` format.
+    .join(",")
 
+  if (formats) {
+    // Adds formats but without `github-actions` format.
     addedArgs.push(`--out-format=${formats}`)
-    userArgs = userArgs.replace(/--out-format=\S*/gi, "").trim()
   }
 
+  // Removes `--out-format` from the user flags because it's already inside `addedArgs`.
+  userArgs = userArgs.replace(/--out-format=\S*/gi, "").trim()
+
   if (isOnlyNewIssues()) {
     if (userArgNames.has(`new`) || userArgNames.has(`new-from-rev`) || userArgNames.has(`new-from-patch`)) {
       throw new Error(`please, don't specify manually --new* args when requesting only new issues`)