feat: create action

index.js

@@ -0,0 +1,7 @@
+const got = require("got");
+
+got.get("https://api.github.com/repos/doitadrian/contreebutors-action/pulls/2/commits", {
+    responseType: "json",
+}).then((response) => {
+    console.log(response.body);
+});

main.ts

@@ -1,25 +1,56 @@
 const { context } = require("@actions/github");
 const core = require("@actions/core");
+const get = require("lodash.get");
+const got = require("got");
 
-const isValidCommitMessage = message => message.match(/^[a-z].*:/);
+type Commit = {
+    message: string;
+};
+
+const isValidCommitMessage = (message): boolean => message.match(/^[a-z].*:/);
+
+const extractCommits = async (): Promise<Commit[]> => {
+    // For "push" events, commits can be found in the "context.payload.commits".
+    const pushCommits = Array.isArray(get(context, "payload.commits"));
+    if (pushCommits) {
+        return context.payload.commits;
+    }
+
+    // For PRs, we need to get a list of commits via the GH API:
+    const prCommitsUrl = typeof get(context, "payload.pull_request.commits_url");
+    if (prCommitsUrl) {
+        try {
+            const { body } = await got.get(prCommitsUrl, {
+                responseType: "json",
+            });
+
+            if (Array.isArray(body)) {
+                return body.map((item) => item.commit);
+            }
+            return [];
+        } catch {
+            return [];
+        }
+    }
+
+    return [];
+};
 
 async function run() {
     core.info(
         `ℹ️ Checking if commit messages are following the Conventional Commits specification...`
     );
 
-    console.log('context', JSON.stringify(context, null, 2));
-
-    const hasCommits = context.payload && Array.isArray(context.payload.commits);
-    if (!hasCommits) {
+    const extractedCommits = await extractCommits();
+    if (extractedCommits.length === 0) {
         core.info(`No commits to check, skipping...`);
         return;
     }
 
     let hasErrors;
     core.startGroup("Commit messages:");
-    for (let i = 0; i < context.payload.commits.length; i++) {
-        let commit = context.payload.commits[i];
+    for (let i = 0; i < extractedCommits.length; i++) {
+        let commit = extractedCommits[i];
         if (isValidCommitMessage(commit.message)) {
             core.info(`✅ ${commit.message}`);
         } else {

package.json

@@ -8,7 +8,9 @@
   "dependencies": {
     "@actions/core": "^1.2.3",
     "@actions/exec": "^1.0.3",
-    "@actions/github": "^2.1.1"
+    "@actions/github": "^2.1.1",
+    "got": "^11.3.0",
+    "lodash.get": "^4.4.2"
   },
   "devDependencies": {
     "@zeit/ncc": "^0.22.0",