Added sample for handling CORS requests. (#721)

* Added sample for handling CORS requests. * Added README * Moved samples to http/ * Minor fix * Fix nits
GoogleCloudPlatform · Aug 30, 2018 · c187157 · c187157
1 parent 77e8968
commit c187157
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diff --git a/functions/http/index.js b/functions/http/index.js
@@ -231,3 +231,57 @@ exports.getSignedUrl = (req, res) => {
  }
 };
 // [END functions_http_signed_url]
+
+// [START functions_http_cors]
+/**
+ * HTTP function that supports CORS requests.
+ *
+ * @param {Object} req Cloud Function request context.
+ * @param {Object} res Cloud Function response context.
+ */
+exports.corsEnabledFunction = (req, res) => {
+ // Set CORS headers for preflight requests
+ // Allows GETs from any origin with the Content-Type header
+ // and caches preflight response for 3600s
+
+ res.set('Access-Control-Allow-Origin', '*');
+
+ if (req.method === 'OPTIONS') {
+ // Send response to OPTIONS requests
+ res.set('Access-Control-Allow-Methods', 'GET');
+ res.set('Access-Control-Allow-Headers', 'Content-Type');
+ res.set('Access-Control-Max-Age', '3600');
+ res.status(204).send('');
+ } else {
+ // Set CORS headers for the main request
+ res.set('Access-Control-Allow-Origin', '*');
+ res.send('Hello World!');
+ }
+};
+// [END functions_http_cors]
+
+// [START functions_http_cors_auth]
+/**
+ * HTTP function that supports CORS requests with credentials.
+ *
+ * @param {Object} req Cloud Function request context.
+ * @param {Object} res Cloud Function response context.
+ */
+exports.corsEnabledFunctionAuth = (req, res) => {
+ // Set CORS headers for preflight requests
+ // Allows GETs from origin https://mydomain.com with Authorization header
+
+ res.set('Access-Control-Allow-Origin', 'https://mydomain.com');
+ res.set('Access-Control-Allow-Credentials', 'true');
+
+ if (req.method === 'OPTIONS') {
+ // Send response to OPTIONS requests
+ res.set('Access-Control-Allow-Methods', 'GET');
+ res.set('Access-Control-Allow-Headers', 'Authorization');
+ res.set('Access-Control-Max-Age', '3600');
+ res.status(204).send('');
+ } else {
+ res.send('Hello World!');
+ }
+};
+// [END functions_http_cors_auth]
diff --git a/functions/http/test/index.test.js b/functions/http/test/index.test.js
@@ -43,9 +43,20 @@ function getMocks () {
  };
  sinon.spy(req, `get`);
 
+ const corsPreflightReq = {
+ method: 'OPTIONS'
+ };
+
+ const corsMainReq = {
+ method: 'GET'
+ };
+
  return {
  req: req,
+ corsPreflightReq: corsPreflightReq,
+ corsMainReq: corsMainReq,
  res: {
+ set: sinon.stub().returnsThis(),
  send: sinon.stub().returnsThis(),
  json: sinon.stub().returnsThis(),
  end: sinon.stub().returnsThis(),
@@ -155,3 +166,41 @@ test.serial(`http:helloContent: should handle other`, (t) => {
  t.true(mocks.res.send.calledOnce);
  t.deepEqual(mocks.res.send.firstCall.args[0], `Hello World!`);
 });
+
+test.serial(`http:cors: should respond to preflight request (no auth)`, (t) => {
+ const mocks = getMocks();
+ const httpSample = getSample();
+
+ httpSample.sample.corsEnabledFunction(mocks.corsPreflightReq, mocks.res);
+
+ t.true(mocks.res.status.calledOnceWith(204));
+ t.true(mocks.res.send.called);
+});
+
+test.serial(`http:cors: should respond to main request (no auth)`, (t) => {
+ const mocks = getMocks();
+ const httpSample = getSample();
+
+ httpSample.sample.corsEnabledFunction(mocks.corsMainReq, mocks.res);
+
+ t.true(mocks.res.send.calledOnceWith(`Hello World!`));
+});
+
+test.serial(`http:cors: should respond to preflight request (auth)`, (t) => {
+ const mocks = getMocks();
+ const httpSample = getSample();
+
+ httpSample.sample.corsEnabledFunctionAuth(mocks.corsPreflightReq, mocks.res);
+
+ t.true(mocks.res.status.calledOnceWith(204));
+ t.true(mocks.res.send.calledOnce);
+});
+
+test.serial(`http:cors: should respond to main request (auth)`, (t) => {
+ const mocks = getMocks();
+ const httpSample = getSample();
+
+ httpSample.sample.corsEnabledFunctionAuth(mocks.corsMainReq, mocks.res);
+
+ t.true(mocks.res.send.calledOnceWith(`Hello World!`));
+});