feat: Add `delete-branch` option to delete PR branches after closing (#190)

* feat: Add `delete-branch` option to delete PR branches after closing

* Fix branch ref

__tests__/main.test.ts

@@ -51,7 +51,8 @@ const DefaultProcessorOptions: IssueProcessorOptions = Object.freeze({
   removeStaleWhenUpdated: false,
   ascending: false,
   skipStaleIssueMessage: false,
-  skipStalePrMessage: false
+  skipStalePrMessage: false,
+  deleteBranch: false
 });
 
 test('empty issue list results in 1 operation', async () => {
@@ -89,6 +90,7 @@ test('processing an issue with no label will make it stale and close it, if it i
 
   expect(processor.staleIssues.length).toEqual(1);
   expect(processor.closedIssues.length).toEqual(1);
+  expect(processor.deletedBranchIssues.length).toEqual(0);
 });
 
 test('processing an issue with no label will make it stale and not close it if days-before-close is set to > 0', async () => {
@@ -895,3 +897,59 @@ test('not providing stalePrMessage takes precedence over skipStalePrMessage', as
   expect(processor.removedLabelIssues.length).toEqual(0);
   expect(processor.staleIssues.length).toEqual(0);
 });
+
+test('git branch is deleted when option is enabled', async () => {
+  const opts = {...DefaultProcessorOptions, deleteBranch: true};
+  const isPullRequest = true;
+  const TestIssueList: Issue[] = [
+    generateIssue(
+      1,
+      'An issue that should have its branch deleted',
+      '2020-01-01T17:00:00Z',
+      isPullRequest,
+      ['Stale']
+    )
+  ];
+
+  const processor = new IssueProcessor(
+    opts,
+    async p => (p == 1 ? TestIssueList : []),
+    async (num, dt) => [],
+    async (issue, label) => new Date().toDateString()
+  );
+
+  await processor.processIssues(1);
+
+  expect(processor.closedIssues.length).toEqual(1);
+  expect(processor.removedLabelIssues.length).toEqual(0);
+  expect(processor.staleIssues.length).toEqual(0);
+  expect(processor.deletedBranchIssues.length).toEqual(1);
+});
+
+test('git branch is not deleted when issue is not pull request', async () => {
+  const opts = {...DefaultProcessorOptions, deleteBranch: true};
+  const isPullRequest = false;
+  const TestIssueList: Issue[] = [
+    generateIssue(
+      1,
+      'An issue that should not have its branch deleted',
+      '2020-01-01T17:00:00Z',
+      isPullRequest,
+      ['Stale']
+    )
+  ];
+
+  const processor = new IssueProcessor(
+    opts,
+    async p => (p == 1 ? TestIssueList : []),
+    async (num, dt) => [],
+    async (issue, label) => new Date().toDateString()
+  );
+
+  await processor.processIssues(1);
+
+  expect(processor.closedIssues.length).toEqual(1);
+  expect(processor.removedLabelIssues.length).toEqual(0);
+  expect(processor.staleIssues.length).toEqual(0);
+  expect(processor.deletedBranchIssues.length).toEqual(0);
+});

action.yml

@@ -56,6 +56,9 @@ inputs:
   skip-stale-issue-message:
     description: 'Skip adding stale message when marking an issue as stale.'
     default: false
+  delete-branch:
+    description: 'Delete the git branch after closing a stale pull request.'
+    default: false
 runs:
   using: 'node12'
   main: 'dist/index.js'

src/IssueProcessor.ts

@@ -14,6 +14,13 @@ export interface Issue {
   locked: boolean;
 }
 
+export interface PullRequest {
+  number: number;
+  head: {
+    ref: string;
+  };
+}
+
 export interface User {
   type: string;
   login: string;
@@ -54,6 +61,7 @@ export interface IssueProcessorOptions {
   ascending: boolean;
   skipStaleIssueMessage: boolean;
   skipStalePrMessage: boolean;
+  deleteBranch: boolean;
 }
 
 /***
@@ -66,6 +74,7 @@ export class IssueProcessor {
 
   readonly staleIssues: Issue[] = [];
   readonly closedIssues: Issue[] = [];
+  readonly deletedBranchIssues: Issue[] = [];
   readonly removedLabelIssues: Issue[] = [];
 
   constructor(
@@ -250,6 +259,14 @@ export class IssueProcessor {
         `Closing ${issueType} because it was last updated on ${issue.updated_at}`
       );
       await this.closeIssue(issue, closeMessage, closeLabel);
+
+      if (this.options.deleteBranch && issue.pull_request) {
+        core.info(
+          `Deleting branch for #${issue.number} as delete-branch option was specified`
+        );
+        await this.deleteBranch(issue);
+        this.deletedBranchIssues.push(issue);
+      }
     } else {
       core.info(
         `Stale ${issueType} is not old enough to close yet (hasComments? ${issueHasComments}, hasUpdate? ${issueHasUpdate})`
@@ -432,6 +449,61 @@ export class IssueProcessor {
     }
   }
 
+  private async getPullRequest(
+    pullNumber: number
+  ): Promise<PullRequest | undefined> {
+    this.operationsLeft -= 1;
+
+    try {
+      const pullRequest = await this.client.pulls.get({
+        owner: context.repo.owner,
+        repo: context.repo.repo,
+        pull_number: pullNumber
+      });
+
+      return pullRequest.data;
+    } catch (error) {
+      core.error(`Error getting pull request ${pullNumber}: ${error.message}`);
+    }
+  }
+
+  // Delete the branch on closed pull request
+  private async deleteBranch(issue: Issue): Promise<void> {
+    core.info(
+      `Delete branch from closed issue #${issue.number} - ${issue.title}`
+    );
+
+    if (this.options.debugOnly) {
+      return;
+    }
+
+    const pullRequest = await this.getPullRequest(issue.number);
+
+    if (!pullRequest) {
+      core.info(
+        `Not deleting branch as pull request not found for issue ${issue.number}`
+      );
+      return;
+    }
+
+    const branch = pullRequest.head.ref;
+    core.info(`Deleting branch ${branch} from closed issue #${issue.number}`);
+
+    this.operationsLeft -= 1;
+
+    try {
+      await this.client.git.deleteRef({
+        owner: context.repo.owner,
+        repo: context.repo.repo,
+        ref: `heads/${branch}`
+      });
+    } catch (error) {
+      core.error(
+        `Error deleting branch ${branch} from issue #${issue.number}: ${error.message}`
+      );
+    }
+  }
+
   // Remove a label from an issue
   private async removeLabel(issue: Issue, label: string): Promise<void> {
     core.info(`Removing label from issue #${issue.number}`);

src/main.ts

@@ -42,7 +42,8 @@ function getAndValidateArgs(): IssueProcessorOptions {
     debugOnly: core.getInput('debug-only') === 'true',
     ascending: core.getInput('ascending') === 'true',
     skipStalePrMessage: core.getInput('skip-stale-pr-message') === 'true',
-    skipStaleIssueMessage: core.getInput('skip-stale-issue-message') === 'true'
+    skipStaleIssueMessage: core.getInput('skip-stale-issue-message') === 'true',
+    deleteBranch: core.getInput('delete-branch') === 'true'
   };
 
   for (const numberInput of [