Add toHaveBeenCalledBefore matcher

This matcher makes sure the 'actual' spy is called before the
'expected' spy.

This code has been written in cooperation with Benjamin Van Ryseghem.

src/core/Spy.js

@@ -1,5 +1,13 @@
 getJasmineRequireObj().Spy = function (j$) {
 
+  var nextOrder = (function() {
+    var order = 0;
+
+    return function() {
+      return order++;
+    };
+  })();
+
   function Spy(name, originalFn) {
     var args = buildArgs(),
       /*`eval` is the only option to preserve both this and context:
@@ -21,6 +29,7 @@ getJasmineRequireObj().Spy = function (j$) {
       spy = function () {
         var callData = {
           object: this,
+          invocationOrder: nextOrder(),
           args: Array.prototype.slice.apply(arguments)
         };
 

src/core/matchers/requireMatchers.js

@@ -15,6 +15,7 @@ getJasmineRequireObj().requireMatchers = function(jRequire, j$) {
       'toContain',
       'toEqual',
       'toHaveBeenCalled',
+      'toHaveBeenCalledBefore',
       'toHaveBeenCalledWith',
       'toHaveBeenCalledTimes',
       'toMatch',

src/core/matchers/toHaveBeenCalledBefore.js

@@ -0,0 +1,40 @@
+getJasmineRequireObj().toHaveBeenCalledBefore = function(j$) {
+
+  var getErrorMsg = j$.formatErrorMsg('<toHaveBeenCalledBefore>', 'expect(<spyObj>).toHaveBeenCalledBefore(<spyObj>)');
+
+  function toHaveBeenCalledBefore() {
+    return {
+      compare: function(firstSpy, latterSpy) {
+        if (!j$.isSpy(firstSpy)) {
+          throw new Error(getErrorMsg('Expected a spy, but got ' + j$.pp(firstSpy) + '.'));
+        }
+        if (!j$.isSpy(latterSpy)) {
+          throw new Error(getErrorMsg('Expected a spy, but got ' + j$.pp(latterSpy) + '.'));
+        }
+
+        var result = { pass: false };
+
+        if (!firstSpy.calls.count()) {
+          result.message = 'Expected spy ' +  firstSpy.and.identity() + ' to have been called.';
+          return result;
+        }
+        if (!latterSpy.calls.count()) {
+          result.message = 'Expected spy ' +  latterSpy.and.identity() + ' to have been called.';
+          return result;
+        }
+
+        result.pass = firstSpy.calls.mostRecent().invocationOrder < latterSpy.calls.mostRecent().invocationOrder;
+
+        if (result.pass) {
+          result.message = 'Expected ' + firstSpy.and.identity() + ' to not have been called before ' + latterSpy.and.identity() + ', but it was';
+        } else {
+          result.message = 'Expected ' + firstSpy.and.identity() + ' to have been called before ' + latterSpy.and.identity();
+        }
+
+        return result;
+      }
+    };
+  }
+
+  return toHaveBeenCalledBefore;
+};