Fix promises and surface IAP errors in Composer GCF Dag triggering

functions/composer-storage-trigger/index.js

@@ -29,9 +29,9 @@ const FormData = require('form-data');
  * https://cloud.google.com/iap/docs/authentication-howto
  *
  * @param {!Object} event The Cloud Functions event.
- * @param {!Function} callback The callback function.
+ * @returns {Promise}
  */
-exports.triggerDag = function triggerDag (event, callback) {
+exports.triggerDag = function triggerDag (event) {
   // Fill in your Composer environment information here.
 
   // The project that holds your function
@@ -50,12 +50,10 @@ exports.triggerDag = function triggerDag (event, callback) {
   const BODY = {'conf': JSON.stringify(event.data)};
 
   // Make the request
-  authorizeIap(CLIENT_ID, PROJECT_ID, USER_AGENT)
+  return authorizeIap(CLIENT_ID, PROJECT_ID, USER_AGENT)
     .then(function iapAuthorizationCallback (iap) {
-      makeIapPostRequest(WEBSERVER_URL, BODY, iap.idToken, USER_AGENT, iap.jwt);
-    })
-    .then(_ => callback(null))
-    .catch(callback);
+      return makeIapPostRequest(WEBSERVER_URL, BODY, iap.idToken, USER_AGENT, iap.jwt);
+    });
 };
 
 /**
@@ -142,24 +140,17 @@ function authorizeIap (clientId, projectId, userAgent) {
    * @param {string} jwt A Json web token used to authenticate the request.
    */
 function makeIapPostRequest (url, body, idToken, userAgent, jwt) {
-  var form = new FormData();
-  form.append('grant_type', 'urn:ietf:params:oauth:grant-type:jwt-bearer');
-  form.append('assertion', jwt);
-
-  return fetch(
-    url, {
-      method: 'POST',
-      body: form
-    })
-    .then(function makeIapPostRequestCallback () {
-      return fetch(url, {
-        method: 'POST',
-        headers: {
-          'User-Agent': userAgent,
-          'Authorization': `Bearer ${idToken}`
-        },
-        body: JSON.stringify(body)
-      });
-    });
+  return fetch(url, {
+    method: 'POST',
+    headers: {
+      'User-Agent': userAgent,
+      'Authorization': `Bearer ${idToken}`
+    },
+    body: JSON.stringify(body)
+  }).then(function checkIapRequestStatus (res) {
+    if (!res.ok) {
+      return res.text().then(body => Promise.reject(body));
+    }
+  });
 }
 // [END composer_trigger]

functions/composer-storage-trigger/test/index.test.js

@@ -19,21 +19,13 @@ const proxyquire = require(`proxyquire`).noCallThru();
 const sinon = require(`sinon`);
 const test = require(`ava`);
 
-function getSample () {
-  const bodyJson = {};
-  const body = {
-    json: sinon.stub().resolves(bodyJson)
-  };
-  const FetchMock = sinon.stub().resolves(body);
-
+function getSample (FetchStub) {
   return {
     program: proxyquire(`../`, {
-      'node-fetch': FetchMock
+      'node-fetch': FetchStub
     }),
     mocks: {
-      fetch: FetchMock,
-      body: body,
-      bodyJson: bodyJson
+      fetch: FetchStub
     }
   };
 }
@@ -45,12 +37,41 @@ test.cb(`Handles error in JSON body`, (t) => {
     }
   };
   const expectedMsg = `Something bad happened.`;
-  const sample = getSample();
-  sample.mocks.bodyJson.error = expectedMsg;
+  const bodyJson = {'error': expectedMsg};
+  const body = {
+    json: sinon.stub().resolves(bodyJson)
+  };
+  const sample = getSample(sinon.stub().resolves(body));
 
-  sample.program.triggerDag(event, (err, message) => {
+  sample.program.triggerDag(event).catch(function (err) {
     t.regex(err, /Something bad happened/);
-    t.is(message, undefined);
+    t.end();
+  });
+});
+
+test.cb(`Handles error in IAP response.`, (t) => {
+  const event = {
+    data: {
+      file: `some-file`
+    }
+  };
+  const expectedMsg = 'Default IAP Error Message.';
+
+  const serviceAccountAccessTokenRes = {
+    json: sinon.stub().resolves({'access_token': 'default-access-token'})
+  };
+  const signJsonClaimRes = {json: sinon.stub().resolves({'signature': 'default-jwt-signature'})};
+  const getTokenRes = {json: sinon.stub().resolves({'id_token': 'default-id-token'})};
+  const makeIapPostRequestRes = {ok: false, text: sinon.stub().resolves(expectedMsg)};
+  const FetchStub = sinon.stub()
+    .onCall(0).resolves(serviceAccountAccessTokenRes)
+    .onCall(1).resolves(signJsonClaimRes)
+    .onCall(2).resolves(getTokenRes)
+    .onCall(3).resolves(makeIapPostRequestRes);
+  const sample = getSample(FetchStub);
+
+  sample.program.triggerDag(event).catch(function (err) {
+    t.is(err, expectedMsg);
     t.end();
   });
 });