From e0c159e82ce73b24398aa9ce88a216b5c4e5a7d2 Mon Sep 17 00:00:00 2001
From: Sebass van Boxel <svboxel@gmail.com>
Date: Wed, 12 Sep 2018 21:41:39 +0200
Subject: [PATCH 1/2] Added test case

---
 test/lib/delete-merged-branch.test.js | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/test/lib/delete-merged-branch.test.js b/test/lib/delete-merged-branch.test.js
index 034fed0..5626aaa 100644
--- a/test/lib/delete-merged-branch.test.js
+++ b/test/lib/delete-merged-branch.test.js
@@ -30,6 +30,23 @@ describe('deleteMergedBranch function', () => {
     repo = payload.repository.name
   })
 
+  describe('branch is merged from fork', () => {
+    beforeEach(async () => {
+      context.payload.pull_request.base.repo.id = 200
+      context.payload.pull_request.head.repo.id = 100
+      context.payload.pull_request.head.label = 'foobar'
+      await deleteMergedBranch(context)
+    })
+
+    it('should log it didn\'t delete the branch', () => {
+      expect(context.log.info).toBeCalledWith(`Closing PR from fork. Keeping ${context.payload.pull_request.head.label}`)
+    })
+
+    it('should NOT call the deleteReference method', () => {
+      expect(context.github.gitdata.deleteReference).not.toHaveBeenCalled()
+    })
+  })
+
   describe('branch is merged', async () => {
     beforeEach(async () => {
       context.payload.pull_request.merged = true

From 037a986ab6f4938f5297baf05fa782b9bf397e56 Mon Sep 17 00:00:00 2001
From: Sebass van Boxel <svboxel@gmail.com>
Date: Wed, 12 Sep 2018 21:54:33 +0200
Subject: [PATCH 2/2] Fix: forks should not branch trigger deletion

---
 lib/delete-merged-branch.js           | 8 ++++++++
 test/lib/delete-merged-branch.test.js | 4 ++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/lib/delete-merged-branch.js b/lib/delete-merged-branch.js
index c433b91..c8f2af5 100644
--- a/lib/delete-merged-branch.js
+++ b/lib/delete-merged-branch.js
@@ -1,8 +1,16 @@
 module.exports = async (context) => {
+  const headRepoId = context.payload.pull_request.head.repo.id
+  const baseRepoId = context.payload.pull_request.base.repo.id
+
   const owner = context.payload.repository.owner.login
   const repo = context.payload.repository.name
   const ref = `heads/${context.payload.pull_request.head.ref}`
 
+  if (headRepoId !== baseRepoId) {
+    context.log.info(`Closing PR from fork. Keeping ${context.payload.pull_request.head.label}`)
+    return
+  }
+
   if (!context.payload.pull_request.merged) {
     context.log.info(`PR was closed but not merged. Keeping ${owner}/${repo}/${ref}`)
     return
diff --git a/test/lib/delete-merged-branch.test.js b/test/lib/delete-merged-branch.test.js
index 5626aaa..6c32189 100644
--- a/test/lib/delete-merged-branch.test.js
+++ b/test/lib/delete-merged-branch.test.js
@@ -18,7 +18,7 @@ describe('deleteMergedBranch function', () => {
       event: {
         event: 'pull_request.closed'
       },
-      payload,
+      payload: JSON.parse(JSON.stringify(payload)), // Njeh...
       github: {
         gitdata: {
           deleteReference
@@ -34,7 +34,7 @@ describe('deleteMergedBranch function', () => {
     beforeEach(async () => {
       context.payload.pull_request.base.repo.id = 200
       context.payload.pull_request.head.repo.id = 100
-      context.payload.pull_request.head.label = 'foobar'
+      context.payload.pull_request.head.label = 'foo:bar'
       await deleteMergedBranch(context)
     })