Improve shared test cases

Author: jhnns

test/testModules/sharedTestCases.js

@@ -2,20 +2,30 @@
 // In case this module was in strict mode, all other modules called by this would also be strict.
 // But when testing if the strict mode is preserved, we must ensure that this module is NOT strict.
 
+// These shared test cases are used to check if the provided implementation of rewire is compatible
+// with the original rewire. Since you can use rewire with client-side bundlers like webpack we need
+// to test the implementation there again.
+// @see https://github.com/jhnns/rewire-webpack
+
 var expect = require("expect.js"),
-    rewire = require("rewire");
+    rewire = require("rewire"),
+    __set__Src = require("../../lib/__set__.js").toString(),
+    __get__Src = require("../../lib/__get__.js").toString(),
+    __with__Src = require("../../lib/__with__.js").toString();
 
 function checkForTypeError(err) {
     expect(err.constructor).to.be(TypeError);
 }
 
 describe("rewire " + (typeof testEnv === "undefined"? "(node)": "(" + testEnv + ")"), function () {
+
     it("should work like require()", function () {
         rewire("./moduleA.js").getFilename();
         require("./moduleA.js").getFilename();
         expect(rewire("./moduleA.js").getFilename()).to.eql(require("./moduleA.js").getFilename());
         expect(rewire("../testModules/someOtherModule.js").filename).to.eql(require("../testModules/someOtherModule.js").filename);
     });
+
     it("should return a fresh instance of the module", function () {
         var someOtherModule = require("./someOtherModule.js"),
             rewiredSomeOtherModule;
@@ -24,6 +34,7 @@ describe("rewire " + (typeof testEnv === "undefined"? "(node)": "(" + testEnv +
         rewiredSomeOtherModule = rewire("./someOtherModule.js");
         expect(rewiredSomeOtherModule.fs).not.to.be("This has been modified");
     });
+
     it("should not cache the rewired module", function () {
         var rewired,
             someOtherModule = require("./someOtherModule.js");
@@ -36,26 +47,42 @@ describe("rewire " + (typeof testEnv === "undefined"? "(node)": "(" + testEnv +
         expect(require("./moduleA.js").someOtherModule).to.be(someOtherModule);
         expect(require("./moduleA.js").someOtherModule.fs).to.be("This has been changed");
     });
-    it("should modify the module so it provides a __set__ - function", function () {
-        expect(rewire("./moduleA.js").__set__).to.be.a(Function);
-        expect(rewire("./moduleB.js").__set__).to.be.a(Function);
+
+    // By comparing the src we can ensure that the provided __set__ function is our tested implementation
+    it("should modify the module so it provides the __set__ - function", function () {
+        expect(rewire("./moduleA.js").__set__.toString()).to.be(__set__Src);
+        expect(rewire("./moduleB.js").__set__.toString()).to.be(__set__Src);
+    });
+
+    // By comparing the src we can ensure that the provided __set__ function is our tested implementation
+    it("should modify the module so it provides the __get__ - function", function () {
+        expect(rewire("./moduleA.js").__get__.toString()).to.be(__get__Src);
+        expect(rewire("./moduleB.js").__get__.toString()).to.be(__get__Src);
     });
-    it("should modify the module so it provides a __get__ - function", function () {
-        expect(rewire("./moduleA.js").__get__).to.be.a(Function);
-        expect(rewire("./moduleB.js").__get__).to.be.a(Function);
+
+    // By comparing the src we can ensure that the provided __set__ function is our tested implementation
+    it("should modify the module so it provides the __with__ - function", function () {
+        expect(rewire("./moduleA.js").__with__.toString()).to.be(__with__Src);
+        expect(rewire("./moduleB.js").__with__.toString()).to.be(__with__Src);
     });
+
     it("should not influence other modules", function () {
         rewire("./moduleA.js");
 
         expect(require("./someOtherModule.js").__set__).to.be(undefined);
         expect(require("./someOtherModule.js").__get__).to.be(undefined);
+        expect(require("./someOtherModule.js").__with__).to.be(undefined);
     });
+
     it("should not override/influence global objects by default", function () {
         // This should throw no exception
         rewire("./moduleA.js").checkSomeGlobals();
         rewire("./moduleB.js").checkSomeGlobals();
     });
-    it("should provide the ability to set private vars", function () {
+
+    // This is just an integration test for the __set__ method
+    // You can find a full test for __set__ under /test/__set__.test.js
+    it("should provide a working __set__ method", function () {
         var rewiredModuleA = rewire("./moduleA.js"),
             newObj = {};
 
@@ -66,12 +93,37 @@ describe("rewire " + (typeof testEnv === "undefined"? "(node)": "(" + testEnv +
         expect(rewiredModuleA.getMyObj()).to.be(newObj);
         rewiredModuleA.__set__("env", "ENVENV");
     });
-    it("should provide the ability to get private vars", function () {
+
+    // This is just an integration test for the __get__ method
+    // You can find a full test for __get__ under /test/__get__.test.js
+    it("should provide a working __get__ method", function () {
         var rewiredModuleA = rewire("./moduleA.js");
 
         expect(rewiredModuleA.__get__("myNumber")).to.be(rewiredModuleA.getMyNumber());
         expect(rewiredModuleA.__get__("myObj")).to.be(rewiredModuleA.getMyObj());
     });
+
+    // This is just an integration test for the __with__ method
+    // You can find a full test for __with__ under /test/__with__.test.js
+    it("should provide a working __with__ method", function () {
+        var rewiredModuleA = rewire("./moduleA.js"),
+            newObj = {};
+
+        expect(rewiredModuleA.getMyNumber()).to.be(0);
+        expect(rewiredModuleA.getMyObj()).to.not.be(newObj);
+
+        rewiredModuleA.__with__({
+            myNumber: 2,
+            myObj: newObj
+        })(function () {
+            expect(rewiredModuleA.getMyNumber()).to.be(2);
+            expect(rewiredModuleA.getMyObj()).to.be(newObj);
+        });
+
+        expect(rewiredModuleA.getMyNumber()).to.be(0);
+        expect(rewiredModuleA.getMyObj()).to.not.be(newObj);
+    });
+
     it("should provide the ability to inject mocks", function (done) {
         var rewiredModuleA = rewire("./moduleA.js"),
             mockedFs = {
@@ -84,6 +136,7 @@ describe("rewire " + (typeof testEnv === "undefined"? "(node)": "(" + testEnv +
         rewiredModuleA.__set__("fs", mockedFs);
         rewiredModuleA.readFileSync();
     });
+
     it("should not influence other modules when injecting mocks", function () {
         var rewiredModuleA = rewire("./moduleA.js"),
             someOtherModule,
@@ -93,6 +146,7 @@ describe("rewire " + (typeof testEnv === "undefined"? "(node)": "(" + testEnv +
         someOtherModule = require("./someOtherModule.js");
         expect(someOtherModule.fs).not.to.be(mockedFs);
     });
+
     it("should provide the ability to mock global objects just within the module", function () {
         var rewiredModuleA = rewire("./moduleA.js"),
             rewiredModuleB = rewire("./moduleB.js"),
@@ -123,6 +177,7 @@ describe("rewire " + (typeof testEnv === "undefined"? "(node)": "(" + testEnv +
             expect(document === documentMock).to.be(false);
         }
     });
+
     it("should be possible to mock global objects that are added on runtime", function () {
         var rewiredModule;
 
@@ -144,26 +199,31 @@ describe("rewire " + (typeof testEnv === "undefined"? "(node)": "(" + testEnv +
             }
         }
     });
+
     it("should not be a problem to have a comment on file end", function () {
         var rewired = rewire("./emptyModule.js");
 
         rewired.__set__("someVar", "hello");
         expect(rewired.__get__("someVar")).to.be("hello");
     });
+
     it("should not influence the original require if nothing has been required within the rewired module", function () {
         rewire("./emptyModule.js"); // nothing happens here because emptyModule doesn't require anything
         expect(require("./moduleA.js").__set__).to.be(undefined); // if restoring the original node require didn't worked, the module would have a setter
     });
+
     it("subsequent calls of rewire should always return a new instance", function () {
         expect(rewire("./moduleA.js")).not.to.be(rewire("./moduleA.js"));
     });
+
     it("should preserve the strict mode", function () {
         var strictModule = rewire("./strictModule.js");
 
         expect(function () {
             strictModule.doSomethingUnstrict();
         }).to.throwException(checkForTypeError);
     });
+
     it("should not modify line numbers in stack traces", function () {
         var throwError = rewire("./throwError.js");
 
@@ -175,9 +235,11 @@ describe("rewire " + (typeof testEnv === "undefined"? "(node)": "(" + testEnv +
             }
         }
     });
+
     it("should throw a TypeError if the path is not a string", function () {
         expect(function () {
             rewire(null);
         }).to.throwException(checkForTypeError);
     });
+
 });