feat: restart renovation after github error

When 404 or 422 errors are encountered writing updates, Renovate will now restart in an attempt to fix it. Usually this is because branches/PRs have been edited or closed while Renovate is running.

Closes #1299

lib/workers/branch/index.js

@@ -116,6 +116,11 @@ async function processBranch(branchConfig) {
       config.forcePr = true;
     }
   } catch (err) {
+    // istanbul ignore if
+    if (err.statusCode === 404 || err.statusCode === 422) {
+      logger.warn({ err }, `Error updating branch: ${err.message}`);
+      return 'platform-error';
+    }
     logger.error({ err }, `Error updating branch: ${err.message}`);
     // Don't throw here - we don't want to stop the other renovations
     return 'error';

lib/workers/repository/index.js

@@ -32,6 +32,10 @@ async function renovateRepository(repoConfig, token, loop = 1) {
       logger.info('Restarting repo renovation after automerge');
       return renovateRepository(repoConfig, token, loop + 1);
     }
+    if (res === 'platform-error') {
+      logger.info('Restarting renovation after platform error');
+      return renovateRepository(repoConfig, token, loop + 1);
+    }
     return res;
   } catch (err) {
     return handleError(config, err);

lib/workers/repository/write.js

@@ -21,6 +21,9 @@ async function writeUpdates(config) {
         // Stop procesing other branches because base branch has been changed by an automerge
         return 'automerged';
       }
+      if (res === 'platform-error') {
+        return 'platform-error';
+      }
     }
     return 'done';
   } finally {

test/workers/repository/index.spec.js

@@ -28,6 +28,7 @@ describe('workers/repository', () => {
     it('writes', async () => {
       determineUpdates.mockReturnValue({ repoIsOnboarded: true });
       writeUpdates.mockReturnValueOnce('automerged');
+      writeUpdates.mockReturnValueOnce('platform-error');
       writeUpdates.mockReturnValueOnce('onboarded');
       const res = await renovateRepository(config, 'some-token');
       expect(res).toMatchSnapshot();

test/workers/repository/write.spec.js

@@ -25,5 +25,12 @@ describe('workers/repository/write', () => {
       expect(res).toEqual('automerged');
       expect(branchWorker.processBranch.mock.calls).toHaveLength(2);
     });
+    it('stops after platform error', async () => {
+      config.branches = [{}, {}];
+      branchWorker.processBranch.mockReturnValueOnce('platform-error');
+      const res = await writeUpdates(config);
+      expect(res).toEqual('platform-error');
+      expect(branchWorker.processBranch.mock.calls).toHaveLength(1);
+    });
   });
 });