Add a method for telling Functions to talk to a local emulator. (#61)

Author: bklimt

firebase-functions/src/androidTest/java/com/google/firebase/functions/CallTest.java

@@ -36,10 +36,14 @@ public static void setUp() {
     app = FirebaseApp.getInstance();
   }
 
+  private void useTestURL(FirebaseFunctions functions) {
+    functions.useFunctionsEmulator("http://10.0.2.2:5005");
+  }
+
   @Test
   public void testData() throws InterruptedException, ExecutionException {
     FirebaseFunctions functions = FirebaseFunctions.getInstance(app);
-    functions.setUseTestURL(true);
+    useTestURL(functions);
 
     Map<String, Object> params = new HashMap<>();
     params.put("bool", true);
@@ -63,7 +67,7 @@ public void testData() throws InterruptedException, ExecutionException {
   @Test
   public void testScalars() throws InterruptedException, ExecutionException {
     FirebaseFunctions functions = FirebaseFunctions.getInstance(app);
-    functions.setUseTestURL(true);
+    useTestURL(functions);
 
     HttpsCallableReference function = functions.getHttpsCallable("scalarTest");
     Task<HttpsCallableResult> result = function.call(17);
@@ -87,7 +91,7 @@ public Task<HttpsCallableContext> getContext() {
                 return Tasks.forResult(context);
               }
             });
-    functions.setUseTestURL(true);
+    useTestURL(functions);
 
     HttpsCallableReference function = functions.getHttpsCallable("tokenTest");
     Task<HttpsCallableResult> result = function.call(new HashMap<>());
@@ -111,7 +115,7 @@ public Task<HttpsCallableContext> getContext() {
                 return Tasks.forResult(context);
               }
             });
-    functions.setUseTestURL(true);
+    useTestURL(functions);
 
     HttpsCallableReference function = functions.getHttpsCallable("instanceIdTest");
     Task<HttpsCallableResult> result = function.call(new HashMap<>());
@@ -123,7 +127,7 @@ public Task<HttpsCallableContext> getContext() {
   @Test
   public void testNull() throws InterruptedException, ExecutionException {
     FirebaseFunctions functions = FirebaseFunctions.getInstance(app);
-    functions.setUseTestURL(true);
+    useTestURL(functions);
 
     HttpsCallableReference function = functions.getHttpsCallable("nullTest");
     Task<HttpsCallableResult> result = function.call(null);
@@ -139,7 +143,7 @@ public void testNull() throws InterruptedException, ExecutionException {
   @Test
   public void testMissingResult() throws InterruptedException, ExecutionException {
     FirebaseFunctions functions = FirebaseFunctions.getInstance(app);
-    functions.setUseTestURL(true);
+    useTestURL(functions);
 
     HttpsCallableReference function = functions.getHttpsCallable("missingResultTest");
     Task<HttpsCallableResult> result = function.call(null);
@@ -155,7 +159,7 @@ public void testMissingResult() throws InterruptedException, ExecutionException
   @Test
   public void testUnhandledError() throws InterruptedException, ExecutionException {
     FirebaseFunctions functions = FirebaseFunctions.getInstance(app);
-    functions.setUseTestURL(true);
+    useTestURL(functions);
 
     HttpsCallableReference function = functions.getHttpsCallable("unhandledErrorTest");
     Task<HttpsCallableResult> result = function.call();
@@ -171,7 +175,7 @@ public void testUnhandledError() throws InterruptedException, ExecutionException
   @Test
   public void testUnknownError() throws InterruptedException, ExecutionException {
     FirebaseFunctions functions = FirebaseFunctions.getInstance(app);
-    functions.setUseTestURL(true);
+    useTestURL(functions);
 
     HttpsCallableReference function = functions.getHttpsCallable("unknownErrorTest");
     Task<HttpsCallableResult> result = function.call();
@@ -187,7 +191,7 @@ public void testUnknownError() throws InterruptedException, ExecutionException {
   @Test
   public void testExplicitError() throws InterruptedException, ExecutionException {
     FirebaseFunctions functions = FirebaseFunctions.getInstance(app);
-    functions.setUseTestURL(true);
+    useTestURL(functions);
 
     HttpsCallableReference function = functions.getHttpsCallable("explicitErrorTest");
     Task<HttpsCallableResult> result = function.call();
@@ -208,7 +212,7 @@ public void testExplicitError() throws InterruptedException, ExecutionException
   @Test
   public void testHttpError() throws InterruptedException, ExecutionException {
     FirebaseFunctions functions = FirebaseFunctions.getInstance(app);
-    functions.setUseTestURL(true);
+    useTestURL(functions);
 
     HttpsCallableReference function = functions.getHttpsCallable("httpErrorTest");
     Task<HttpsCallableResult> result = function.call();

firebase-functions/src/main/java/com/google/firebase/functions/FirebaseFunctions.java

@@ -65,8 +65,8 @@ public class FirebaseFunctions {
   // The region to use for all function references.
   private final String region;
 
-  // If true, use an Android emulator localhost URL instead of the normal one.
-  private boolean useTestURL = false;
+  // The format to use for constructing urls from region, projectId, and name.
+  private String urlFormat = "https://%1$s-%2$s.cloudfunctions.net/%3$s";
 
   @VisibleForTesting
   FirebaseFunctions(
@@ -172,36 +172,22 @@ public HttpsCallableReference getHttpsCallable(String name) {
    */
   @VisibleForTesting
   URL getURL(String function) {
-    StringBuilder builder = new StringBuilder();
-    if (useTestURL) {
-      builder
-          .append("http://10.0.2.2:5005/")
-          .append(projectId)
-          .append("/")
-          .append(region)
-          .append("/");
-    } else {
-      builder
-          .append("https://")
-          .append(region)
-          .append("-")
-          .append(projectId)
-          .append(".cloudfunctions.net/");
-    }
-    builder.append(function);
+    String str = String.format(urlFormat, region, projectId, function);
     try {
-      return new URL(builder.toString());
+      return new URL(str);
     } catch (MalformedURLException mfe) {
-      // This should never happen.
       throw new IllegalStateException(mfe);
     }
   }
 
-  /** Sets a flag for this instance to use a test URL instead of the normal URL. */
-  @VisibleForTesting
-  void setUseTestURL(boolean value) {
-    // TODO: Change this once we hook up the test backend with hexa instead of the emulator.
-    useTestURL = value;
+  /**
+   * Changes this instance to point to a Cloud Functions emulator running locally.
+   * See https://firebase.google.com/docs/functions/local-emulator
+   *
+   * @param origin The origin of the local emulator, such as "http://10.0.2.2:5005".
+   */
+  public void useFunctionsEmulator(String origin) {
+    urlFormat = origin + "/%2$s/%1$s/%3$s";
   }
 
   /**