Properly inform the user if he has not enabled the GitHub integration when diffing

commands/pipelines/diff.js

@@ -108,6 +108,24 @@ function* diff(targetApp, downstreamApp, githubToken, herokuUserAgent) {
   }
 }
 
+function* findDownstreamApps(heroku, coupling) {
+  const allApps = yield cli.action(`Fetching apps from pipeline`,
+    heroku.request({
+      method: 'GET',
+      path: `/pipelines/${coupling.pipeline.id}/apps`,
+      headers: { Accept: PIPELINES_HEADER }
+    }));
+
+  const sourceStage = coupling.stage;
+  const downstreamStage = PROMOTION_ORDER[PROMOTION_ORDER.indexOf(sourceStage) + 1];
+  if (downstreamStage === null || PROMOTION_ORDER.indexOf(sourceStage) < 0) {
+    throw new Error(`Unable to infer the downstream stage for ${sourceStage}`);
+  }
+  return allApps.filter(function (app) {
+    return app.coupling.stage === downstreamStage;
+  });
+}
+
 module.exports = {
   topic: 'pipelines',
   command: 'diff',
@@ -128,26 +146,28 @@ module.exports = {
     }
     const targetAppId = coupling.app.id;
 
-    const allApps = yield cli.action(`Fetching apps from pipeline`,
-      heroku.request({
-        method: 'GET',
-        path: `/pipelines/${coupling.pipeline.id}/apps`,
-        headers: { 'Accept': PIPELINES_HEADER }
-      }));
-
-    const sourceStage = coupling.stage;
-    const downstreamStage = PROMOTION_ORDER[PROMOTION_ORDER.indexOf(sourceStage) + 1];
-    if (downstreamStage === null || PROMOTION_ORDER.indexOf(sourceStage) < 0) {
+    // Find downstream apps
+    let downstreamApps;
+    try {
+      downstreamApps = yield findDownstreamApps(heroku, coupling);
+    } catch (err) {
       return cli.error(`Unable to diff ${targetAppName}`);
     }
-    const downstreamApps = allApps.filter(function(app) {
-      return app.coupling.stage === downstreamStage;
-    });
 
     if (downstreamApps.length < 1) {
       return cli.error(`Cannot diff ${targetAppName} as there are no downstream apps configured`);
     }
 
+    // Fetch GitHub token for the user
+    let githubAccount;
+    try {
+      githubAccount = yield kolkrabbiRequest(`/account/github/token`, heroku.options.token);
+    } catch (err) {
+      cli.hush(err);
+      cli.error(`You need to enable the GitHub integration for your Heroku account`);
+      return cli.error(`See https://devcenter.heroku.com/articles/github-integration for help`);
+    }
+
     // Fetch GitHub repo/latest release hash for [target, downstream[0], .., downstream[n]] apps
     const wrappedGetAppInfo = co.wrap(getAppInfo);
     const appInfoPromises = [wrappedGetAppInfo(heroku, targetAppName, targetAppId)];
@@ -165,9 +185,6 @@ module.exports = {
       return cli.error(`No release was found for ${targetAppName}, unable to diff`);
     }
 
-    // Fetch GitHub token for the user
-    const githubAccount = yield kolkrabbiRequest(`/account/github/token`, heroku.options.token);
-
     // Diff [{target, downstream[0]}, {target, downstream[1]}, .., {target, downstream[n]}]
     const downstreamAppsInfo = appInfo.slice(1);
     for (let downstreamAppInfo of downstreamAppsInfo) {

test/commands/pipelines/diff.js

@@ -67,6 +67,12 @@ describe('pipelines:diff', function () {
       .reply(200, [targetApp, downstreamApp1, downstreamApp2]);
   }
 
+  function mockGithubAccount() {
+    nock(kolkrabbiApi)
+      .get(`/account/github/token`)
+      .reply(200, { github: { token: 'github-token' } });
+  }
+
   beforeEach(function () {
     cli.mockConsole();
   });
@@ -75,7 +81,7 @@ describe('pipelines:diff', function () {
     nock.cleanAll();
   });
 
-  describe('for app without a pipeline', function () {
+  describe('for apps without a pipeline', function () {
     it('should return an error', function () {
       const req = nock(api)
         .get(`/apps/${targetApp.name}/pipeline-couplings`)
@@ -89,9 +95,11 @@ describe('pipelines:diff', function () {
     });
   });
 
-  describe('for app with a pipeline but no downstream apps', function () {
-    it('should return an error', function () {
+  describe('for apps with a pipeline', function () {
+    beforeEach(function () {
       mockPipelineCoupling();
+    });
+    it('should return an error for pipelines with no downstream apps', function () {
       nock(api)
         .get(`/pipelines/${pipeline.id}/apps`)
         .reply(200, [targetApp]);
@@ -101,12 +109,23 @@ describe('pipelines:diff', function () {
         expect(cli.stderr).to.contain('no downstream apps');
       });
     });
+    it('should return an error if no GitHub account is associated', function () {
+      mockApps();
+      nock(kolkrabbiApi)
+        .get(`/account/github/token`)
+        .reply(404);
+      return cmd.run({ app: targetApp.name })
+      .then(function () {
+        expect(cli.stderr).to.contain('You need to enable the GitHub integration');
+      });
+    });
   });
 
   describe('for invalid apps with a pipeline', function () {
     beforeEach(function () {
       mockPipelineCoupling();
       mockApps();
+      mockGithubAccount();
     });
 
     it('should return an error if the app is not connected to GitHub', function () {
@@ -144,6 +163,7 @@ describe('pipelines:diff', function () {
     beforeEach(function () {
       mockPipelineCoupling();
       mockApps();
+      mockGithubAccount();
 
       // Mock the GitHub apps for targetApp and downstreamApp1:
       nock(kolkrabbiApi)
@@ -152,9 +172,7 @@ describe('pipelines:diff', function () {
         .get(`/apps/${downstreamApp1.id}/github`)
         .reply(200, downstreamApp1Github)
         .get(`/apps/${downstreamApp2.id}/github`)
-        .reply(200, downstreamApp2Github)
-        .get(`/account/github/token`)
-        .reply(200, { github: { token: 'github-token' } });
+        .reply(200, downstreamApp2Github);
 
       // Mock latest release/slug endpoints for two apps:
       nock(api)