From 5bdbcb0ac6089db1411319e4990897682ad7938f Mon Sep 17 00:00:00 2001
From: Michael Fix <mrfix84@gmail.com>
Date: Thu, 29 Aug 2019 18:38:56 -0700
Subject: [PATCH] Update pulls (#76)

* merge base branch if required

* add unit test

* enable for me for now
---
 src/api.js          |  3 ++-
 src/pull/labeled.js | 29 +++++++++++++++++++++++-
 test/index.test.js  | 55 ++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 84 insertions(+), 3 deletions(-)

diff --git a/src/api.js b/src/api.js
index d499d16..ecda8e7 100644
--- a/src/api.js
+++ b/src/api.js
@@ -29,7 +29,8 @@ exports.getPullRequest = function getPullRequest(github, data) {
       repo,
       pull_number: number,
       headers: {
-        Accept: 'application/vnd.github.symmetra-preview+json'
+        Accept:
+          'application/vnd.github.symmetra-preview+json,application/vnd.github.shadow-cat-preview+json'
       }
     })
     .then(_ => _.data)
diff --git a/src/pull/labeled.js b/src/pull/labeled.js
index 5672df2..4a43c53 100644
--- a/src/pull/labeled.js
+++ b/src/pull/labeled.js
@@ -111,7 +111,6 @@ module.exports.process = robot => async ({
     pull = await getPullRequest(github, { owner, repo, number })
   } catch (error) {
     const Sentry = require('@sentry/node')
-    robot.log('Get pull request failed', error, { installation_id, owner, repo, number, method })
     Sentry.configureScope(scope => {
       scope.setUser({ username: owner, id: installation_id })
       Sentry.captureException(error)
@@ -200,6 +199,34 @@ module.exports.process = robot => async ({
         await mergeAttempt(2)
       }
     }
+  } else if (pull.mergeable_state === STATUS.BEHIND) {
+    // TODO use getBranchProtection?
+    const { data: branch } = await github.repos.getBranch({
+      owner: pull.base.user.login,
+      repo: pull.base.repo.name,
+      branch: pull.base.ref
+    })
+    if (
+      branch.protected &&
+      branch.protection &&
+      branch.protection.enabled &&
+      branch.protection.required_status_checks &&
+      branch.protection.required_status_checks.enforcement_level !== 'off' &&
+      branch.protection.required_status_checks.contexts.length &&
+      // TODO
+      (owner === 'carbon-app' || owner === 'mfix22')
+    ) {
+      await github.pulls.updateBranch({
+        owner,
+        repo,
+        pull_number: number,
+        expected_head_sha: pull.base.sha,
+        headers: {
+          accept: 'application/vnd.github.lydian-preview+json'
+        }
+      })
+      return
+    }
   } else if (pull.mergeable_state === STATUS.DIRTY) {
     // don't retry if there are merge conflicts
     return
diff --git a/test/index.test.js b/test/index.test.js
index 5fbd197..e247e13 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -202,7 +202,18 @@ beforeEach(async () => {
       }),
       getCombinedStatusForRef: jest
         .fn()
-        .mockResolvedValue({ data: { state: 'success', statuses: [] } })
+        .mockResolvedValue({ data: { state: 'success', statuses: [] } }),
+      getBranch: jest.fn().mockResolvedValue({
+        data: {
+          protected: true,
+          protection: {
+            enabled: true,
+            required_status_checks: {
+              contexts: ['Build']
+            }
+          }
+        }
+      })
     },
     apps: {
       listRepos: jest.fn().mockResolvedValue({
@@ -224,6 +235,9 @@ beforeEach(async () => {
     },
     users: {
       getByUsername: jest.fn().mockResolvedValue({ data: { email: 'test@test.com' } })
+    },
+    pulls: {
+      updateBranch: jest.fn().mockResolvedValue({ data: {} })
     }
   }
   robot.auth = () => Promise.resolve(github)
@@ -379,6 +393,45 @@ describe('pull_request', () => {
     })
   })
 
+  test('Will not update branch if a pull request is "behind" and branch requires it', async () => {
+    github.pullRequests.get.mockResolvedValue({
+      data: {
+        mergeable: true,
+        mergeable_state: 'behind',
+        base: {
+          sha: 'fake sha ahhh',
+          user: { login: 'mfix22' },
+          repo: { name: 'test-issue-bot', owner: { login: 'mfix22' } }
+        },
+        head: {
+          sha: 0,
+          user: { login: 'mfix22' },
+          repo: { name: 'test-issue-bot', owner: { login: 'mfix22' } }
+        }
+      }
+    })
+
+    await robot.receive(
+      payload({
+        name: 'pull_request',
+        threadType: 'pull_request',
+        labels: ['merge'],
+        number: 98
+      })
+    )
+
+    await wait(10)
+
+    expect(github.pullRequests.merge).not.toHaveBeenCalled()
+    expect(github.pulls.updateBranch).toHaveBeenCalledWith({
+      expected_head_sha: 'fake sha ahhh',
+      owner: 'mfix22',
+      pull_number: 98,
+      repo: 'test-issue-bot',
+      headers: { accept: 'application/vnd.github.lydian-preview+json' }
+    })
+  })
+
   test('Will not merge a pull request with state `dirty`', async () => {
     github.pullRequests.get.mockResolvedValue({
       data: {