Update squash commit message to include all PR commit authors

#77

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2017 Uber Technologies, Inc.
+Copyright (c) 2019 Uber Technologies, Inc.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

__tests__/__fixtures__/issue_comment.created.js

@@ -0,0 +1,27 @@
+// webhook: https://developer.github.com/v3/activity/events/types/#webhook-payload-example-13
+// webhook.issue (pull request): https://developer.github.com/v3/issues/#response
+module.exports = {
+  action: 'created',
+  issue: {
+    html_url: 'https://github.com/fusionjs/test-repo/pull/1',
+    number: 1,
+    pull_request: {
+      url: 'https://api.github.com/repos/fusionjs/test-repo/pulls/1',
+    },
+    state: 'open',
+    title: 'Test PR',
+  },
+  comment: {
+    body: '!merge',
+    user: {
+      login: 'test-user',
+      type: 'User',
+    },
+  },
+  repository: {
+    name: 'test-repo',
+    owner: {
+      login: 'fusionjs',
+    },
+  },
+};

__tests__/__fixtures__/listCommits.js

@@ -0,0 +1,27 @@
+// https://developer.github.com/v3/pulls/#list-commits-on-a-pull-request
+module.exports = [
+  {
+    commit: {
+      author: {
+        name: 'test-user',
+        email: '[email protected]',
+      },
+    },
+  },
+  {
+    commit: {
+      author: {
+        name: 'test-user2',
+        email: '[email protected]',
+      },
+    },
+  },
+  {
+    commit: {
+      author: {
+        name: 'test-user3',
+        email: '[email protected]',
+      },
+    },
+  },
+];

__tests__/__fixtures__/reviewUserPermissionLevel.js

@@ -0,0 +1,4 @@
+// https://developer.github.com/v3/repos/collaborators/#review-a-users-permission-level
+module.exports = {
+  permission: 'admin',
+};

__tests__/index.js

@@ -1,13 +1,58 @@
-/** Copyright (c) 2017 Uber Technologies, Inc.
+/** Copyright (c) 2019 Uber Technologies, Inc.
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  */
 
 /* eslint-env jest */
 
-const t = require('assert');
+const nock = require('nock');
+const mergePRApp = require('../index.js');
+const {Probot} = require('probot');
+const fixtures = {
+  listCommits: require('./__fixtures__/listCommits.js'),
+  payload: require('./__fixtures__/issue_comment.created.js'),
+  reviewUserPermissionLevel: require('./__fixtures__/reviewUserPermissionLevel.js'),
+};
 
-test('dummy test', () => {
-  t.ok(true, 'dummy assertion passed');
+nock.disableNetConnect();
+
+describe('probot-app-merge-pr', () => {
+  let probot;
+
+  beforeEach(() => {
+    probot = new Probot({});
+    const app = probot.load(mergePRApp);
+
+    // just return a test token
+    app.app = () => 'test';
+  });
+
+  test('merges the PR with commit authors as co-authors', async () => {
+    nock('https://api.github.com')
+      .get('/repos/fusionjs/test-repo/collaborators/test-user/permission')
+      .reply(200, fixtures.reviewUserPermissionLevel)
+      .get('/repos/fusionjs/test-repo/contents/.github/merge-pr.yml')
+      .reply(404)
+      .get('/repos/fusionjs/test-repo/pulls/1/commits')
+      .reply(200, fixtures.listCommits);
+
+    const mergeRequest = new Promise(resolve => {
+      nock('https://api.github.com')
+        .put('/repos/fusionjs/test-repo/pulls/1/merge', resolve)
+        .reply(200);
+    });
+
+    const expectedMessage = `https://github.com/fusionjs/test-repo/pull/1
+
+Co-authored-by: test-user2 <[email protected]>
+Co-authored-by: test-user3 <[email protected]>`;
+
+    await probot.receive({name: 'issue_comment', payload: fixtures.payload});
+    expect(await mergeRequest).toEqual({
+      commit_title: 'Test PR',
+      commit_message: expectedMessage,
+      merge_method: 'squash',
+    });
+  });
 });

index.js

@@ -1,4 +1,4 @@
-/** Copyright (c) 2017 Uber Technologies, Inc.
+/** Copyright (c) 2019 Uber Technologies, Inc.
  *
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
@@ -38,11 +38,45 @@ module.exports = robot => {
     }
 
     try {
+      let commit_message = issue.html_url;
+
+      // add all PR commiters as co-authors
+      // https://help.github.com/articles/creating-a-commit-with-multiple-authors/
+      if (merge_method === 'squash') {
+        const prNumber = pull_request.url.split('/').slice(-1)[0];
+        const commitList = await github.pullRequests.listCommits(
+          context.repo({
+            number: prNumber,
+          }),
+        );
+        const authorTrailers = commitList.data.reduce((result, item) => {
+          const {
+            commit: {
+              author: {email, name},
+            },
+          } = item;
+
+          if (name !== user.login) {
+            const trailer = `Co-authored-by: ${name} <${email}>`;
+
+            if (!result.includes(trailer)) {
+              result.push(trailer);
+            }
+          }
+
+          return result;
+        }, []);
+
+        if (authorTrailers.length) {
+          commit_message += '\n\n' + authorTrailers.join('\n');
+        }
+      }
+
       await github.pullRequests.merge(
         context.repo({
           number: issue.number,
           commit_title: issue.title,
-          commit_message: issue.html_url,
+          commit_message,
           merge_method,
         }),
       );

package.json

@@ -20,13 +20,18 @@
     "eslint-plugin-prettier": "2.6.2",
     "jest": "23.6.0",
     "localtunnel": "1.9.1",
+    "nock": "^10.0.6",
     "prettier": "1.15.3"
   },
   "jest": {
+    "testPathIgnorePatterns": [
+      "__fixtures__"
+    ],
     "testURL": "http://localhost:3000/"
   },
   "engines": {
-    "node": ">= 8.6.0"
+    "node": ">= 8.6.0",
+    "yarn": ">=1.12"
   },
   "license": "MIT"
 }