chore(promises): Wait for promises explicitly (#70)

See #68 for details

Author: sjelin

.jshintignore

@@ -1 +1 @@
-spec/asyncAwaitSpec.js
+./spec/asyncAwaitSpec.js

index.js

@@ -6,17 +6,6 @@
 
 var webdriver = require('selenium-webdriver');
 
-/**
- * Wraps a function so that all passed arguments are ignored.
- * @param {!Function} fn The function to wrap.
- * @return {!Function} The wrapped function.
- */
-function seal(fn) {
-  return function() {
-    fn();
-  };
-}
-
 /**
  * Validates that the parameter is a function.
  * @param {Object} functionToValidate The function to validate.
@@ -59,10 +48,28 @@ function validateString(stringtoValidate) {
   }
 }
 
+/**
+ * Calls a function once the control flow is idle
+ * @param {webdriver.promise.ControlFlow} flow The Web Driver control flow
+ * @param {!Function} fn The function to call
+ */
+function callWhenIdle(flow, fn) {
+  if (flow.isIdle()) {
+    fn();
+  } else {
+    flow.once(webdriver.promise.ControlFlow.EventType.IDLE, function() {
+      fn();
+    });
+  }
+}
+
+
 /**
  * Wraps a function so it runs inside a webdriver.promise.ControlFlow and
  * waits for the flow to complete before continuing.
+ * @param {!webdriver.promise.ControlFlow} flow The WebDriver control flow.
  * @param {!Function} globalFn The function to wrap.
+ * @param {!string} fnName The name of the function being wrapped (e.g. `'it'`).
  * @return {!Function} The new function.
  */
 function wrapInControlFlow(flow, globalFn, fnName) {
@@ -78,30 +85,38 @@ function wrapInControlFlow(flow, globalFn, fnName) {
 
         flow.execute(function controlFlowExecute() {
           return new webdriver.promise.Promise(function(fulfill, reject) {
+            function wrappedReject(err) {
+              var wrappedErr = new Error(err);
+              reject(wrappedErr);
+            }
             if (async) {
               // If testFn is async (it expects a done callback), resolve the promise of this
               // test whenever that callback says to.  Any promises returned from testFn are
               // ignored.
               var proxyDone = fulfill;
-              proxyDone.fail = function(err) {
-                var wrappedErr = new Error(err);
-                reject(wrappedErr);
-              };
+              proxyDone.fail = wrappedReject;
               testFn(proxyDone);
             } else {
               // Without a callback, testFn can return a promise, or it will
               // be assumed to have completed synchronously.
-              fulfill(testFn());
+              var ret = testFn();
+              if (webdriver.promise.isPromise(ret)) {
+                ret.then(fulfill, wrappedReject);
+              } else {
+                fulfill(ret);
+              }
             }
           }, flow);
-        }, 'Run ' + fnName + description + ' in control flow').then(seal(done), function(err) {
-          if (!err) {
-            err = new Error('Unknown Error');
-            err.stack = '';
+        }, 'Run ' + fnName + description + ' in control flow').then(
+          callWhenIdle.bind(null, flow, done), function(err) {
+            if (!err) {
+              err = new Error('Unknown Error');
+              err.stack = '';
+            }
+            err.stack = err.stack + '\nFrom asynchronous test: \n' + driverError.stack;
+            callWhenIdle(flow, done.fail.bind(done, err));
           }
-          err.stack = err.stack + '\nFrom asynchronous test: \n' + driverError.stack;
-          done.fail(err);
-        });
+        );
       };
     }
 

scripts/test.sh

@@ -9,7 +9,7 @@ $CMD
 [ "$?" -eq 0 ] || exit 1
 echo
 
-EXPECTED_RESULTS="16 specs, 15 failures"
+EXPECTED_RESULTS="18 specs, 16 failures"
 echo "### running failing specs (expecting $EXPECTED_RESULTS)"
 CMD=$CMD_BASE$FAILING_SPECS
 echo "### $CMD"

spec/adapterSpec.js

@@ -242,4 +242,25 @@ describe('webdriverJS Jasmine adapter', function() {
       expect(spec3.description).toBe('test3');
     });
   });
+
+  describe('native promises', function() {
+    var currentTest = null;
+
+    it('should wait for webdriver events sent from native promise', function() {
+      currentTest = 'A';
+      return new Promise(function(resolve) {
+        setTimeout(function() {
+          fakeDriver.sleep(100).then(function() {
+            expect(currentTest).toBe('A');
+          });
+          resolve();
+        }, 100);
+      });
+    });
+
+    it('should not start a test before another finishes', function(done) {
+      currentTest = 'B';
+      setTimeout(done, 200);
+    });
+  });
 });

spec/errorSpec.js

@@ -102,4 +102,24 @@ describe('things that should fail', function() {
     expect(fakeDriver.getDecimalNumber()).toBeCloseTo(3.1);
     expect(fakeDriver.getDecimalNumber()).not.toBeCloseTo(3.14);
   });
+
+  describe('native promises', function() {
+    var testADone = false;
+
+    it('should handle rejection from native promise', function() {
+      return new Promise(function(resolve, reject) {
+        setTimeout(function() {
+          fakeDriver.sleep(100).then(function() {
+            testADone = true;
+          });
+          reject('Rejected promise');
+        }, 100);
+      });
+    });
+
+    it('should not start a test before another finishes', function(done) {
+      expect(testADone).toBe(true); // this test actually passes
+      setTimeout(done, 200);
+    });
+  });
 });