fix: prevent unhandled promise rejection in apps:destroy

src/commands/apps/destroy.ts

@@ -2,7 +2,7 @@ import {Command, flags} from '@heroku-cli/command'
 import * as color from '@heroku/heroku-cli-util/color'
 import {Args, ux} from '@oclif/core'
 
-import * as git from '../../lib/ci/git.js'
+import {gitService} from '../../lib/ci/git.js'
 import ConfirmCommand from '../../lib/confirm-command.js'
 
 export default class Destroy extends Command {
@@ -35,13 +35,15 @@ export default class Destroy extends Command {
      * you want, and they can all point to the same url.
      * The only requirement is that the "name" is unique.
      */
-    if (git.inGitRepo()) {
+    if (gitService.inGitRepo()) {
       // delete git remotes pointing to this app
-      const remotes = await git.listRemotes()
-      await Promise.all([
-        remotes.get(git.gitUrl(app))?.map(({name}) => git.rmRemote(name)),
-        remotes.get(git.sshGitUrl(app))?.map(({name}) => git.rmRemote(name)),
+      const remotes = await gitService.listRemotes()
+      // Deduplicate remote names (same name appears for fetch and push)
+      const names = new Set([
+        ...(remotes.get(gitService.gitUrl(app))?.map(({name}) => name) ?? []),
+        ...(remotes.get(gitService.sshGitUrl(app))?.map(({name}) => name) ?? []),
       ])
+      await Promise.all([...names].map(name => gitService.rmRemote(name)))
     }
 
     ux.action.stop()

src/lib/ci/git.ts

@@ -162,7 +162,6 @@ async function createRemote(remote: string, url: string) {
   return null
 }
 
-// GitService class for easier testing/stubbing
 export class GitService {
   async createArchive(ref: string) {
     return createArchive(ref)
@@ -172,9 +171,29 @@ export class GitService {
     return githubRepository()
   }
 
+  gitUrl(app?: string) {
+    return gitUrl(app)
+  }
+
+  inGitRepo() {
+    return inGitRepo()
+  }
+
+  async listRemotes() {
+    return listRemotes()
+  }
+
   async readCommit(commit: string) {
     return readCommit(commit)
   }
+
+  async rmRemote(remote: string) {
+    return rmRemote(remote)
+  }
+
+  sshGitUrl(app: string) {
+    return sshGitUrl(app)
+  }
 }
 
 // Export a shared instance for use across commands

test/unit/commands/apps/destroy.unit.test.ts

@@ -1,8 +1,10 @@
 import {runCommand} from '@heroku-cli/test-utils'
 import {expect} from 'chai'
 import nock from 'nock'
+import {createSandbox} from 'sinon'
 
 import Destroy from '../../../../src/commands/apps/destroy.js'
+import {gitService} from '../../../../src/lib/ci/git.js'
 
 describe('apps:destroy', function () {
   let api: nock.Scope
@@ -43,4 +45,73 @@ describe('apps:destroy', function () {
 
     expect(error?.message).to.include('No app specified.')
   })
+
+  describe('git remote cleanup', function () {
+    const sandbox = createSandbox()
+
+    afterEach(function () {
+      sandbox.restore()
+    })
+
+    it('removes duplicate git remotes without error (issue #3677)', async function () {
+      api
+        .get('/apps/myapp').reply(200, {name: 'myapp'})
+        .delete('/apps/myapp').reply(200)
+
+      const rmRemoteCalls: string[] = []
+
+      // Stub gitService methods
+      sandbox.stub(gitService, 'inGitRepo').returns(true)
+      // Return a map with duplicate entries (fetch + push for same remote)
+      const mockRemotes = new Map([
+        ['https://git.heroku.com/myapp.git', [
+          {kind: '(fetch)', name: 'heroku'},
+          {kind: '(push)', name: 'heroku'},
+        ]],
+      ])
+      sandbox.stub(gitService, 'listRemotes').resolves(mockRemotes)
+      sandbox.stub(gitService, 'gitUrl').returns('https://git.heroku.com/myapp.git')
+      sandbox.stub(gitService, 'sshGitUrl').returns('git@git.heroku.com:myapp.git')
+      sandbox.stub(gitService, 'rmRemote').callsFake(async (name: string) => {
+        rmRemoteCalls.push(name)
+      })
+
+      await runCommand(Destroy, ['--app', 'myapp', '--confirm', 'myapp'])
+
+      // Verify rmRemote was called exactly once (deduplication worked)
+      expect(rmRemoteCalls.length).to.equal(1)
+      expect(rmRemoteCalls[0]).to.equal('heroku')
+    })
+
+    it('removes multiple different remotes', async function () {
+      api
+        .get('/apps/myapp').reply(200, {name: 'myapp'})
+        .delete('/apps/myapp').reply(200)
+
+      const rmRemoteCalls: string[] = []
+
+      sandbox.stub(gitService, 'inGitRepo').returns(true)
+      // Multiple remotes with duplicates (fetch + push for each)
+      const mockRemotes = new Map([
+        ['https://git.heroku.com/myapp.git', [
+          {kind: '(fetch)', name: 'heroku'},
+          {kind: '(push)', name: 'heroku'},
+          {kind: '(fetch)', name: 'production'},
+          {kind: '(push)', name: 'production'},
+        ]],
+      ])
+      sandbox.stub(gitService, 'listRemotes').resolves(mockRemotes)
+      sandbox.stub(gitService, 'gitUrl').returns('https://git.heroku.com/myapp.git')
+      sandbox.stub(gitService, 'sshGitUrl').returns('git@git.heroku.com:myapp.git')
+      sandbox.stub(gitService, 'rmRemote').callsFake(async (name: string) => {
+        rmRemoteCalls.push(name)
+      })
+
+      await runCommand(Destroy, ['--app', 'myapp', '--confirm', 'myapp'])
+
+      // Verify both remotes were removed exactly once each
+      expect(rmRemoteCalls.length).to.equal(2)
+      expect(rmRemoteCalls).to.have.members(['heroku', 'production'])
+    })
+  })
 })