fix: make fetch promise patching safe

Closes #451

Author: marclaval

karma.conf.js

@@ -6,6 +6,7 @@ module.exports = function (config) {
     files: [
       'node_modules/systemjs/dist/system-polyfills.js',
       'node_modules/systemjs/dist/system.src.js',
+      'node_modules/whatwg-fetch/fetch.js',
       {pattern: 'test/assets/**/*.*', watched: true, served: true, included: false},
       {pattern: 'build/**/*.js.map', watched: true, served: true, included: false},
       {pattern: 'build/**/*.js', watched: true, served: true, included: false},

lib/zone.ts

@@ -1155,7 +1155,7 @@ const Zone: ZoneType = (function(global: any) {
       }
       // ignore output to prevent error;
       fetchPromise.then(() => null, () => null);
-      if (fetchPromise.constructor != NativePromise) {
+      if (fetchPromise.constructor != NativePromise && fetchPromise.constructor != ZoneAwarePromise) {
         patchThen(fetchPromise.constructor);
       }
     }

package.json

@@ -38,6 +38,7 @@
     "@types/systemjs": "^0.19.30",
     "concurrently": "^2.2.0",
     "es6-promise": "^3.0.2",
+    "whatwg-fetch": "^1.0.0",
     "gulp": "^3.8.11",
     "gulp-rename": "^1.2.2",
     "gulp-rollup": "^2.3.0",

test/common/Promise.spec.ts

@@ -341,17 +341,22 @@ describe('Promise', ifEnvSupports('Promise', function () {
       });
     });
 
-    it('should work for blob response', function(done) {
-      testZone.run(function() {
-        global['fetch']('/base/test/assets/sample.json').then(function(response: any) {
+    it('should work for blob response', function (done) {
+      testZone.run(function () {
+        global['fetch']('/base/test/assets/sample.json').then(function (response:any) {
           var fetchZone = Zone.current;
           expect(fetchZone).toBe(testZone);
 
-          response.blob().then(function(blob) {
-            expect(Zone.current).toBe(fetchZone);
-            expect(blob instanceof Blob).toEqual(true);
+          // Android 4.3- doesn't support response.blob()
+          if (response.blob) {
+            response.blob().then(function (blob) {
+              expect(Zone.current).toBe(fetchZone);
+              expect(blob instanceof Blob).toEqual(true);
+              done();
+            });
+          } else {
             done();
-          });
+          }
         });
       });
     });
@@ -362,13 +367,19 @@ describe('Promise', ifEnvSupports('Promise', function () {
           var fetchZone = Zone.current;
           expect(fetchZone).toBe(testZone);
 
-          response.arrayBuffer().then(function(blob) {
-            expect(Zone.current).toBe(fetchZone);
-            expect(blob instanceof ArrayBuffer).toEqual(true);
+          // Android 4.3- doesn't support response.arrayBuffer()
+          if (response.arrayBuffer) {
+            response.arrayBuffer().then(function (blob) {
+              expect(Zone.current).toBe(fetchZone);
+              expect(blob instanceof ArrayBuffer).toEqual(true);
+              done();
+            });
+          } else {
             done();
-          });
+          }
         });
       });
     });
+
   }));
 }));