Provide better diffs for object graphs that include objectContaining

Turns this output:
    Expected $[0].foo = Object({ a: 4, b: 5 }) to equal <jasmine.objectContaining(Object({ a: 1, c: 3 }))>.

into this:
    Expected $[0].foo.a = 4 to equal 1.
    Expected $[0].foo.c = undefined to equal 3.

And turns this output:
    Expected spy jasmineDone to have been called with:
       [ ... snipped very long expected call ]
    but actual calls were:
       [ ... snipped very long actual call ]

    Call 0:
      Expected $[0] = Object({ overallStatus: 'failed', totalTime: 1, incompleteReason: undefined, order: Order({ random: true, seed: '88732', sort: Function }), failedExpectations: [ Object({ matcherName: 'toBeResolved', passed: false, message: 'Suite "a suite" ran a "toBeResolved" expectation after it finished.
      Did you forget to return or await the result of expectAsync?', error: undefined, errorForStack: Error, actual: [object Promise], expected: [  ], globalErrorType: 'lateExpeztation' }) ], deprecationWarnings: [  ] }) to equal <jasmine.objectContaining(Object({ failedExpectations: [ <jasmine.objectContaining(Object({ passed: false, globalErrorType: 'lateExpectation', message: 'Suite "a suite" ran a "toBeResolved" expectation after it finished.
      Did you forget to return or await the result of expectAsync?', matcherName: 'toBeResolved' }))> ] }))>.

into this:
    Expected spy jasmineDone to have been called with:
       [ ... snipped very long expected call ]
    but actual calls were:
       [ ... snipped very long actual call ]

    Call 0:
      Expected $[0].failedExpectations[0].globalErrorType = 'lateExpeztation' to equal 'lateExpectation'.

lib/jasmine-core/jasmine.js

@@ -2519,6 +2519,27 @@ getJasmineRequireObj().ObjectContaining = function(j$) {
     return true;
   };
 
+  ObjectContaining.prototype.valuesForDiff_ = function(other) {
+    if (!j$.isObject_(other)) {
+      return {
+        self: this.jasmineToString(),
+        other: other
+      };
+    }
+
+    var filteredOther = {};
+    Object.keys(this.sample).forEach(function (k) {
+      // eq short-circuits comparison of objects that have different key sets,
+      // so include all keys even if undefined.
+      filteredOther[k] = other[k];
+    });
+
+    return {
+      self: this.sample,
+      other: filteredOther
+    };
+  };
+
   ObjectContaining.prototype.jasmineToString = function() {
     return '<jasmine.objectContaining(' + j$.pp(this.sample) + ')>';
   };
@@ -4192,7 +4213,16 @@ getJasmineRequireObj().matchersUtil = function(j$) {
     return obj && j$.isA_('Function', obj.asymmetricMatch);
   }
 
-  function asymmetricMatch(a, b, customTesters, diffBuilder) {
+  function asymmetricDiff(a, b, aStack, bStack, customTesters, diffBuilder) {
+    if (j$.isFunction_(b.valuesForDiff_)) {
+      var values = b.valuesForDiff_(a);
+      eq(values.other, values.self, aStack, bStack, customTesters, diffBuilder);
+    } else {
+      diffBuilder.record(a, b);
+    }
+  }
+
+  function asymmetricMatch(a, b, aStack, bStack, customTesters, diffBuilder) {
     var asymmetricA = isAsymmetric(a),
         asymmetricB = isAsymmetric(b),
         result;
@@ -4204,6 +4234,8 @@ getJasmineRequireObj().matchersUtil = function(j$) {
     if (asymmetricA) {
       result = a.asymmetricMatch(b, customTesters);
       if (!result) {
+        // TODO: Do we want to build an asymmetric diff when the actual was an
+        // asymmeteric equality tester? Might be confusing.
         diffBuilder.record(a, b);
       }
       return result;
@@ -4212,7 +4244,7 @@ getJasmineRequireObj().matchersUtil = function(j$) {
     if (asymmetricB) {
       result = b.asymmetricMatch(a, customTesters);
       if (!result) {
-        diffBuilder.record(a, b);
+        asymmetricDiff(a, b, aStack, bStack, customTesters, diffBuilder);
       }
       return result;
     }
@@ -4230,7 +4262,7 @@ getJasmineRequireObj().matchersUtil = function(j$) {
   function eq(a, b, aStack, bStack, customTesters, diffBuilder) {
     var result = true, i;
 
-    var asymmetricResult = asymmetricMatch(a, b, customTesters, diffBuilder);
+    var asymmetricResult = asymmetricMatch(a, b, aStack, bStack, customTesters, diffBuilder);
     if (!j$.util.isUndefined(asymmetricResult)) {
       return asymmetricResult;
     }

spec/core/asymmetric_equality/ObjectContainingSpec.js

@@ -96,4 +96,65 @@ describe("ObjectContaining", function() {
 
     expect(containing.asymmetricMatch({foo: "fooBar"}, [tester])).toBe(true);
   });
+
+  describe("valuesForDiff_", function() {
+    describe("when other is not an object", function() {
+      it("sets self to jasmineToString()", function () {
+        var containing = new jasmineUnderTest.ObjectContaining({}),
+          result = containing.valuesForDiff_('a');
+
+        expect(result).toEqual({
+          self: '<jasmine.objectContaining(Object({  }))>',
+          other: 'a'
+        });
+      });
+    });
+
+    describe("when other is an object", function() {
+      it("includes keys that are present in both other and sample", function() {
+        var sample = {a: 1, b: 2},
+          other = {a: 3, b: 4},
+          containing = new jasmineUnderTest.ObjectContaining(sample),
+          result = containing.valuesForDiff_(other);
+
+        expect(result.self).not.toBeInstanceOf(jasmineUnderTest.ObjectContaining);
+        expect(result).toEqual({
+          self: sample,
+          other: other
+        });
+      });
+
+      it("includes keys that are present in only sample", function() {
+        var sample = {a: 1, b: 2},
+          other = {a: 3},
+          containing = new jasmineUnderTest.ObjectContaining(sample),
+          result = containing.valuesForDiff_(other);
+
+        expect(result.self).not.toBeInstanceOf(jasmineUnderTest.ObjectContaining);
+        expect(containing.valuesForDiff_(other)).toEqual({
+          self: sample,
+          other: {
+            a: 3,
+            b: undefined
+          }
+        });
+      });
+
+      it("omits keys that are present only in other", function() {
+        var sample = {a: 1, b: 2},
+          other = {a: 3, b: 4, c: 5},
+          containing = new jasmineUnderTest.ObjectContaining(sample),
+          result = containing.valuesForDiff_(other);
+
+        expect(result.self).not.toBeInstanceOf(jasmineUnderTest.ObjectContaining);
+        expect(result).toEqual({
+          self: sample,
+          other: {
+            a: 3,
+            b: 4
+          }
+        });
+      });
+    });
+  });
 });

spec/core/matchers/matchersUtilSpec.js

@@ -593,6 +593,42 @@ describe("matchersUtil", function() {
         expect(['foo']).toEqual(['foo']);
       });
     });
+
+    describe("Building diffs for asymmetric equality testers", function() {
+      it("diffs the values returned by valuesForDiff_", function() {
+        var tester = {
+            asymmetricMatch: function() { return false; },
+            valuesForDiff_: function() {
+              return {
+                self: 'asymmetric tester value',
+                other: 'other value'
+              }
+            }
+          },
+          diffBuilder = jasmine.createSpyObj('diffBuilder', ['record', 'withPath']);
+        diffBuilder.withPath.and.callFake(function(p, block) { block() });
+        debugger;
+        jasmineUnderTest.matchersUtil.equals({x: 42}, {x: tester}, [], diffBuilder);
+
+        expect(diffBuilder.withPath).toHaveBeenCalledWith('x', jasmine.any(Function));
+        expect(diffBuilder.record). toHaveBeenCalledWith(
+          'other value', 'asymmetric tester value'
+        );
+      });
+
+      it("records both objects when the tester does not implement valuesForDiff", function() {
+        var tester = {
+            asymmetricMatch: function() { return false; },
+          },
+          diffBuilder = jasmine.createSpyObj('diffBuilder', ['record', 'withPath']);
+        diffBuilder.withPath.and.callFake(function(p, block) { block() });
+        debugger;
+        jasmineUnderTest.matchersUtil.equals({x: 42}, {x: tester}, [], diffBuilder);
+
+        expect(diffBuilder.withPath).toHaveBeenCalledWith('x', jasmine.any(Function));
+        expect(diffBuilder.record). toHaveBeenCalledWith(42, tester);
+      });
+    });
   });
 
   describe("contains", function() {

spec/core/matchers/toEqualSpec.js

@@ -350,6 +350,20 @@ describe("toEqual", function() {
     expect(compareEquals(actual, expected).message).toEqual(message);
   });
 
+  it("reports mismatches involving objectContaining", function() {
+    var actual = {x: {a: 1, b: 4, c: 3, extra: 'ignored'}};
+    var expected = {x: jasmineUnderTest.objectContaining({a: 1, b: 2, c: 3})};
+    expect(compareEquals(actual, expected).message).toEqual('Expected $.x.b = 4 to equal 2.')
+  });
+
+  it("reports mismatches between a non-object and objectContaining", function() {
+    var actual = {x: 1};
+    var expected = {x: jasmineUnderTest.objectContaining({a: 1})};
+    expect(compareEquals(actual, expected).message).toEqual(
+      "Expected $.x = 1 to equal '<jasmine.objectContaining(Object({ a: 1 }))>'."
+    );
+  });
+
   // == Sets ==
 
   it("reports mismatches between Sets", function() {

src/core/asymmetric_equality/ObjectContaining.js

@@ -41,6 +41,27 @@ getJasmineRequireObj().ObjectContaining = function(j$) {
     return true;
   };
 
+  ObjectContaining.prototype.valuesForDiff_ = function(other) {
+    if (!j$.isObject_(other)) {
+      return {
+        self: this.jasmineToString(),
+        other: other
+      };
+    }
+
+    var filteredOther = {};
+    Object.keys(this.sample).forEach(function (k) {
+      // eq short-circuits comparison of objects that have different key sets,
+      // so include all keys even if undefined.
+      filteredOther[k] = other[k];
+    });
+
+    return {
+      self: this.sample,
+      other: filteredOther
+    };
+  };
+
   ObjectContaining.prototype.jasmineToString = function() {
     return '<jasmine.objectContaining(' + j$.pp(this.sample) + ')>';
   };

src/core/matchers/matchersUtil.js

@@ -55,7 +55,16 @@ getJasmineRequireObj().matchersUtil = function(j$) {
     return obj && j$.isA_('Function', obj.asymmetricMatch);
   }
 
-  function asymmetricMatch(a, b, customTesters, diffBuilder) {
+  function asymmetricDiff(a, b, aStack, bStack, customTesters, diffBuilder) {
+    if (j$.isFunction_(b.valuesForDiff_)) {
+      var values = b.valuesForDiff_(a);
+      eq(values.other, values.self, aStack, bStack, customTesters, diffBuilder);
+    } else {
+      diffBuilder.record(a, b);
+    }
+  }
+
+  function asymmetricMatch(a, b, aStack, bStack, customTesters, diffBuilder) {
     var asymmetricA = isAsymmetric(a),
         asymmetricB = isAsymmetric(b),
         result;
@@ -67,6 +76,8 @@ getJasmineRequireObj().matchersUtil = function(j$) {
     if (asymmetricA) {
       result = a.asymmetricMatch(b, customTesters);
       if (!result) {
+        // TODO: Do we want to build an asymmetric diff when the actual was an
+        // asymmeteric equality tester? Might be confusing.
         diffBuilder.record(a, b);
       }
       return result;
@@ -75,7 +86,7 @@ getJasmineRequireObj().matchersUtil = function(j$) {
     if (asymmetricB) {
       result = b.asymmetricMatch(a, customTesters);
       if (!result) {
-        diffBuilder.record(a, b);
+        asymmetricDiff(a, b, aStack, bStack, customTesters, diffBuilder);
       }
       return result;
     }
@@ -93,7 +104,7 @@ getJasmineRequireObj().matchersUtil = function(j$) {
   function eq(a, b, aStack, bStack, customTesters, diffBuilder) {
     var result = true, i;
 
-    var asymmetricResult = asymmetricMatch(a, b, customTesters, diffBuilder);
+    var asymmetricResult = asymmetricMatch(a, b, aStack, bStack, customTesters, diffBuilder);
     if (!j$.util.isUndefined(asymmetricResult)) {
       return asymmetricResult;
     }