introducing problem matchers

.github/rust.json

@@ -0,0 +1,44 @@
+{
+    "problemMatcher": [
+        {
+            "owner": "cargo-common",
+            "pattern": [
+                {
+                    "regexp": "^(warning|warn|error)(\\[(\\S*)\\])?: (.*)$",
+                    "severity": 1,
+                    "message": 4,
+                    "code": 3
+                },
+                {
+                    "regexp": "^\\s+-->\\s(\\S+):(\\d+):(\\d+)$",
+                    "file": 1,
+                    "line": 2,
+                    "column": 3
+                }
+            ]
+        },
+        {
+            "owner": "cargo-test",
+            "pattern": [
+                {
+                    "regexp": "^.*panicked\\s+at\\s+'(.*)',\\s+(.*):(\\d+):(\\d+)$",
+                    "message": 1,
+                    "file": 2,
+                    "line": 3,
+                    "column": 4
+                }
+            ]
+        },
+        {
+            "owner": "cargo-fmt",
+            "pattern": [
+                {
+                    "regexp": "^(Diff in (\\S+)) at line (\\d):",
+                    "message": 1,
+                    "file": 2,
+                    "line": 3
+                }
+            ]
+        }
+    ]
+}

README.md

@@ -45,7 +45,18 @@ For more details, check out [`action.yml`].
 
 [`action.yml`]: https://github.com/hecrj/setup-rust-action/blob/master/action.yml
 
+
+## Problem Matchers
+
+This action registers the following [problem matchers](https://github.com/actions/toolkit/blob/master/docs/problem-matchers.md) to surface relavant information inline with changeset diffs.
+
+* `cargo-common` matches common cases of errors and warnings
+* `cargo-test` matches cargo test errors
+* `cargo-fmt` matches rust format errors
+
+To disable any or all of these you can use the `remove-matcher` directive documented [here](https://github.com/actions/toolkit/blob/master/docs/commands.md#problem-matchers)
+
 # Contributing / Feedback
 
 Contributions and feedback are welcome! Feel free to open any issues or pull
-requests.
+requests.

lib/main.js

@@ -18,6 +18,7 @@ Object.defineProperty(exports, "__esModule", { value: true });
 const core = __importStar(require("@actions/core"));
 const exec = __importStar(require("@actions/exec"));
 const rustup = __importStar(require("./rustup"));
+const path = __importStar(require("path"));
 function run() {
     return __awaiter(this, void 0, void 0, function* () {
         try {
@@ -38,6 +39,8 @@ function run() {
                 ]);
                 yield exec.exec('rustup', ['default', version]);
             }
+            const matchersPath = path.join(__dirname, '..', '.github');
+            console.log(`##[add-matcher]${path.join(matchersPath, 'go.json')}`);
         }
         catch (error) {
             core.setFailed(error.message);

src/main.ts

@@ -1,7 +1,7 @@
 import * as core from '@actions/core';
 import * as exec from '@actions/exec';
 import * as rustup from './rustup';
-import * as os from 'os';
+import * as path from 'path';
 
 async function run() {
   try {
@@ -30,6 +30,10 @@ async function run() {
 
       await exec.exec('rustup', ['default', version]);
     }
+
+    const matchersPath = path.join(__dirname, '..', '.github');
+    console.log(`##[add-matcher]${path.join(matchersPath, 'go.json')}`);
+
   } catch (error) {
     core.setFailed(error.message);
   }