Add extractCallbackFromArguments()

cucumber · Jun 7, 2011 · 55fe390 · 55fe390
1 parent 95f5a07
commit 55fe390
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Showing 2 changed files with 51 additions and 18 deletions.
diff --git a/lib/cucumber.js b/lib/cucumber.js
@@ -339,13 +339,18 @@ Cucumber.Ast.TreeWalker = function(features, supportCodeLibrary, listeners) {
       return userFunction;
     },
 
+    extractCallbackFromArguments: function extractCallbackFromArguments(argumentsObject) {
+      var nonPayloadArguments = self.extractNonMessagePayloadArgumentsFromArguments(argumentsObject);
+      var callback            = nonPayloadArguments.pop();
+      return callback;
+    },
+
     extractNonMessagePayloadArgumentsFromArguments: function extractNonMessagePayloadArgumentsFromArguments(argumentsObject) {
       var argumentsArray      = Cucumber.Util.Arguments(argumentsObject);
       var nonPayloadArguments = argumentsArray.slice(-Cucumber.Ast.TreeWalker.NON_PAYLOAD_TRAILING_PARAMETERS_COUNT);
       return nonPayloadArguments;
     },
 
-    extractCallbackFromArguments: TODO("extractCallbackFromArguments()"),
     wrapUserFunctionAndAfterMessageBroadcast: TODO("wrapUserFunctionAndAfterMessageBroadcast()"),
     broadcastBeforeMessage: TODO("broadcastBeforeMessage()"),
 

diff --git a/spec/cucumber/ast/tree_walker_spec.js b/spec/cucumber/ast/tree_walker_spec.js
@@ -273,6 +273,35 @@ describe("Cucumber.Ast.TreeWalker", function() {
     });
   });
 
+  describe("extractNonMessagePayloadArgumentsFromArguments()", function() {
+    var argumentsObject, argumentsArray, nonPayloadArguments;
+
+    beforeEach(function() {
+      nonPayloadArguments = createSpy("Non payload arguments");
+      argumentsObject     = createSpy("Arguments object");
+      argumentsArray      = createSpyWithStubs("Cucumber util arguments array",
+                                           {slice: nonPayloadArguments});
+      spyOn(Cucumber.Util, 'Arguments').andReturn(argumentsArray);
+    });
+
+    it("transforms the arguments object into an array", function() {
+      treeWalker.extractNonMessagePayloadArgumentsFromArguments(argumentsObject);
+      expect(Cucumber.Util.Arguments).toHaveBeenCalledWith(argumentsObject);
+    });
+
+     it("slices the payload parameters off", function() {
+       treeWalker.extractNonMessagePayloadArgumentsFromArguments(argumentsObject);
+       expect(argumentsArray.slice).toHaveBeenCalledWith(
+        -Cucumber.Ast.TreeWalker.NON_PAYLOAD_TRAILING_PARAMETERS_COUNT
+      );
+    });
+
+    it("returns the array slice", function() {
+      var returned = treeWalker.extractNonMessagePayloadArgumentsFromArguments(argumentsObject);
+      expect(returned).toBe(nonPayloadArguments);
+    });
+  });
+
   describe("extractUserFunctionFromArguments()", function() {
     var argumentsObject, userFunction, nonPayloadArguments;
 
@@ -300,35 +329,34 @@ describe("Cucumber.Ast.TreeWalker", function() {
     });
   });
 
-  describe("extractNonMessagePayloadArgumentsFromArguments()", function() {
-    var argumentsObject, argumentsArray, nonPayloadArguments;
+  describe("extractCallbackFromArguments()", function() {
+    var argumentsObject, callback, nonPayloadArguments;
 
     beforeEach(function() {
-      nonPayloadArguments = createSpy("Non payload arguments");
+      callback            = createSpy("User function");
       argumentsObject     = createSpy("Arguments object");
-      argumentsArray      = createSpyWithStubs("Cucumber util arguments array",
-                                           {slice: nonPayloadArguments});
-      spyOn(Cucumber.Util, 'Arguments').andReturn(argumentsArray);
+      nonPayloadArguments = createSpyWithStubs("Non payload arguments", {pop: callback});
+      spyOn(treeWalker, 'extractNonMessagePayloadArgumentsFromArguments').
+        andReturn(nonPayloadArguments);
     });
 
-    it("transforms the arguments object into an array", function() {
-      treeWalker.extractNonMessagePayloadArgumentsFromArguments(argumentsObject);
-      expect(Cucumber.Util.Arguments).toHaveBeenCalledWith(argumentsObject);
+    it("extracts the non-payload arguments from the arguments object", function() {
+      treeWalker.extractCallbackFromArguments(argumentsObject);
+      expect(treeWalker.extractNonMessagePayloadArgumentsFromArguments).toHaveBeenCalledWith(argumentsObject);
     });
 
-     it("slices the payload parameters off", function() {
-       treeWalker.extractNonMessagePayloadArgumentsFromArguments(argumentsObject);
-       expect(argumentsArray.slice).toHaveBeenCalledWith(
-        -Cucumber.Ast.TreeWalker.NON_PAYLOAD_TRAILING_PARAMETERS_COUNT
-      );
+    it("pops the last argument out of the non-payload arguments", function() {
+      treeWalker.extractCallbackFromArguments(argumentsObject);
+      expect(nonPayloadArguments.pop).toHaveBeenCalled();
     });
 
-    it("returns the array slice", function() {
-      var returned = treeWalker.extractNonMessagePayloadArgumentsFromArguments(argumentsObject);
-      expect(returned).toBe(nonPayloadArguments);
+    it("returns the unshifted argument", function() {
+      var returned = treeWalker.extractCallbackFromArguments(argumentsObject);
+      expect(returned).toBe(callback);
     });
   });
 
+
   /*
   describe("broadcastUserFunction()", function() {
     var message, userFunction, callback;