feat: ✨ Automatically delete branches when issues are closed

README.md

@@ -377,6 +377,19 @@ the following is true for your app configuration:
 - Your branch name contains the string `issue-` (case insensitive) followed by
   the issue number, for example: `Project-A-Issue-123-Rewrite_in_Clojure`
 
+## Automatically delete issue branch after closing an issue
+
+This app can delete issue branches for you when a related issue is closed. You
+can enable this feature with:
+
+```yaml
+autoDeleteBranch: true
+```
+
+Be aware that the app needs to be able to find the issue number in the branch
+name, otherwise this feature will not work. See also the explanation in [this
+section](#Automatically-close-issues-after-a-pull-request-merge).
+
 ## Default source branch
 
 You can override the source branch (by default

src/entities/Config.ts

@@ -3,6 +3,7 @@ export interface Config {
     branchName: string;
     autoLinkIssue: boolean;
     autoCloseIssue: boolean;
+    autoDeleteBranch: boolean;
     defaultBranch?: string;
     branches: Array<BranchConfig>;
     copyIssueLabelsToPR: boolean;
@@ -40,6 +41,7 @@ export function getDefaultConfig(): Config {
         branchName: 'full',
         autoLinkIssue: false,
         autoCloseIssue: false,
+        autoDeleteBranch: false,
         branches: [],
         copyIssueLabelsToPR: false,
         copyIssueAssigneeToPR: false,

src/github.ts

@@ -200,6 +200,19 @@ export async function branchExists(ctx: Context<any>, branchName: string) {
     }
 }
 
+export async function deleteBranch(ctx: Context<any>, branchName: string) {
+    const owner = getRepoOwnerLogin(ctx)
+    const repo = getRepoName(ctx)
+    try {
+        await ctx.octokit.git.deleteRef({
+            owner: owner, repo: repo, ref: `heads/${branchName}`
+        })
+        return true
+    } catch (err) {
+        return false
+    }
+}
+
 export function getSourceBranch(ctx: Context<any>, config: Config) {
     const branchConfig = getIssueBranchConfig(ctx, config)
     if (branchConfig && branchConfig.name) {

src/probot.ts

@@ -14,6 +14,7 @@ import {gitDate, gitSha, version} from "./version";
 import {isRunningInGitHubActions, logMemoryUsage} from "./utils";
 import {MongoDbService} from "./services/MongoDbService";
 import {WebhookEvent} from "./entities/WebhookEvent";
+import {issueClosed} from "./webhooks/issue-closed";
 
 
 export default (app: Probot, {getRouter}: ApplicationFunctionOptions) => {
@@ -34,6 +35,9 @@ function setupEventHandlers(app: Probot) {
     app.on('issues.assigned', async ctx => {
         await issueAssigned(app, ctx);
     });
+    app.on('issues.closed', async ctx => {
+        await issueClosed(app, ctx);
+    });
     app.on('issue_comment.created', async ctx => {
         const comment = ctx.payload.comment.body;
         await commentCreated(app, ctx, comment);

src/webhooks/issue-closed.ts

@@ -0,0 +1,28 @@
+import {Context, Probot} from "probot";
+import {loadConfig} from "../config";
+import {logMemoryUsage} from "../utils";
+import {Config} from "../entities/Config";
+import {branchExists, deleteBranch, getBranchNameFromIssue} from "../github";
+
+export async function issueClosed(app: Probot, ctx: Context<any>) {
+    const config = await loadConfig(ctx);
+    if (config) {
+        if (!config.autoDeleteBranch) {
+            return;
+        }
+        await handle(app, ctx, config);
+        logMemoryUsage(app);
+    }
+}
+
+async function handle(app: Probot, ctx: Context<any>, config: Config) {
+    const branchName = await getBranchNameFromIssue(ctx, config)
+    if (await branchExists(ctx, branchName)) {
+        const result = await deleteBranch(ctx, branchName);
+        if (result) {
+            app.log.info(`Deleted branch ${branchName}`);
+        } else {
+            app.log.error(`Failed to delete branch ${branchName}`);
+        }
+    }
+}

tests/webhooks/issue-assigned.test.ts

@@ -26,5 +26,5 @@ test('do nothing if configured to skip', async () => {
         "description": "Something isn't working"
     }] as any;
 
-    await probot.receive({id: '', name: 'issues', payload: issueAssignedPayload as any});
+    await probot.receive({id: '', name: 'issues', payload: payload as any});
 });

tests/webhooks/issue-closed.test.ts

@@ -0,0 +1,40 @@
+import {Probot} from "probot";
+import issueOpenedPayload from "../test-fixtures/issues.opened.json";
+import {initNock, initProbot, nockConfig, nockEmptyConfig, nockExistingBranch} from "../test-helpers";
+
+let probot: Probot
+
+beforeAll(() => {
+    initNock()
+})
+
+beforeEach(() => {
+    probot = initProbot()
+})
+
+test('do nothing if not configured', async () => {
+    nockEmptyConfig();
+    const payload = issueOpenedPayload;
+    payload.action = 'closed';
+    const deleteRef = jest.fn()
+    // @ts-ignore
+    probot.state.octokit.git.deleteRef = deleteRef
+
+    await probot.receive({id: '', name: 'issues', payload: payload as any});
+
+    expect(deleteRef).toHaveBeenCalledTimes(0);
+});
+
+test('do delete branch', async () => {
+    nockConfig('autoDeleteBranch: true');
+    nockExistingBranch('issue-1-Test_issue', 'abcd1234');
+    const payload = issueOpenedPayload;
+    payload.action = 'closed';
+    const deleteRef = jest.fn()
+    // @ts-ignore
+    probot.state.octokit.git.deleteRef = deleteRef
+
+    await probot.receive({id: '', name: 'issues', payload: payload as any});
+
+    expect(deleteRef).toHaveBeenCalledTimes(1);
+});