Cleanup of mjsunit.js code and make assertEquals more strict.

test/mjsunit/mjsunit.js

Index: test/mjsunit/mjsunit.js
diff --git a/test/mjsunit/mjsunit.js b/test/mjsunit/mjsunit.js
index 41dd24036411b38e3fa4beb197d167e10b719175..faa5a43829a69f3dedbd39f3c524e6884f62e8fe 100644
--- a/test/mjsunit/mjsunit.js
+++ b/test/mjsunit/mjsunit.js
@@ -43,236 +43,313 @@ MjsUnitAssertionError.prototype.toString = function () {
 };
 
 
-function classOf(object) {
-  var string = Object.prototype.toString.call(object);
-  // String has format [object <ClassName>].
-  return string.substring(8, string.length - 1);
-}
+// Expected and found values the same objects, or the same primitive
+// values.
+// For known primitive values, please use assertEquals.
+var assertSame;
+
+// Expected and found values are identical primitive values or functions
+// or similarly structured objects (checking internal properties
+// of, e.g., Number and Date objects, the elements of arrays
+// and the properties of non-Array objects).
+var assertEquals;
+
+// The found object is an Array with the same length and elements
+// as the expected object. The expected object doesn't need to be an Array,
+// as long as it's "array-ish".
+var assertArrayEquals;
+
+// The found object must have the same enumerable properties as the
+// expected object. The type of object isn't checked.
+var assertPropertiesEqual;
+
+// Assert that the string conversion of the found value is equal to
+// the expected string. Only kept for backwards compatability, please
+// check the real structure of the found value.
+var assertToStringEquals;
+
+// Checks that the found value is true. Use with boolean expressions
+// for tests that doesn't have their own assertXXX function.
+var assertTrue;
+
+// Checks that the found value is false.
+var assertFalse;
+
+// Checks that the found value is null. Kept for historical compatability,
+// please just use assertEquals(null, expected).
+var assertNull;
+
+// Checks that the found value is *not* null.
+var assertNotNull;
+
+// Assert that the passed function or eval code throws an exception.
+// The optional second argument is an exception constructor that the
+// thrown exception is checked against with "instanceof".
+// The optional third argument is a message type string that is compared
+// to the type property on the thrown exception.
+var assertThrows;
+
+// Assert that the passed function or eval code does not throw an exception.
+var assertDoesNotThrow;
+
+// Asserts that the found value is an instance of the constructor passed
+// as the second argument.
+var assertInstanceof;
+
+// Assert that this code is never executed (i.e., always fails if executed).
+var assertUnreachable;
+
+(function () {  // Scope for utility functions.
+
+  function classOf(object) {
+    // Argument must not be null or undefined.
+    var string = Object.prototype.toString.call(object);
+    // String has format [object <ClassName>].
+    return string.substring(8, string.length - 1);
+  }
 
 
-function MjsUnitToString(value) {
-  switch (typeof value) {
-    case "string":
-      return JSON.stringify(value);
-    case "number":
-      if (value === 0 && (1 / value) < 0) return "-0";
-      // FALLTHROUGH.
-    case "boolean":
-    case "undefined":
-    case "function":
-      return String(value);
-    case "object":
-      if (value === null) return "null";
-      var objectClass = classOf(value);
-      switch (objectClass) {
+  function PrettyPrint(value) {
+    switch (typeof value) {
+      case "string":
+        return JSON.stringify(value);
+      case "number":
+        if (value === 0 && (1 / value) < 0) return "-0";
+        // FALLTHROUGH.
+      case "boolean":
+      case "undefined":
+      case "function":
+        return String(value);
+      case "object":
+        if (value === null) return "null";
+        var objectClass = classOf(value);
+        switch (objectClass) {
         case "Number":
         case "String":
         case "Boolean":
         case "Date":
-          return objectClass + "(" + MjsUnitToString(value.valueOf()) + ")";
+          return objectClass + "(" + PrettyPrint(value.valueOf()) + ")";
         case "RegExp":
           return value.toString();
         case "Array":
-          return "[" + value.map(MjsUnitArrayElementToString).join(",") + "]";
+          return "[" + value.map(PrettyPrintArrayElement).join(",") + "]";
         case "Object":
           break;
         default:
           return objectClass + "()";
-      }
-      // [[Class]] is "Object".
-      var constructor = value.constructor.name;
-      if (name) return name + "()";
-      return "Object()";
-    default:
-      return "-- unknown value --";
+        }
+        // [[Class]] is "Object".
+        var name = value.constructor.name;
+        if (name) return name + "()";
+        return "Object()";
+      default:
+        return "-- unknown value --";
+    }
   }
-}
 
 
-function MjsUnitArrayElementToString(value, index, array) {
-  if (value === undefined && !(index in array)) return "";
-  return MjsUnitToString(value);
-}
-
-
-function fail(expected, found, name_opt) {
-  var message = "Fail" + "ure";
-  if (name_opt) {
-    // Fix this when we ditch the old test runner.
-    message += " (" + name_opt + ")";
+  function PrettyPrintArrayElement(value, index, array) {
+    if (value === undefined && !(index in array)) return "";
+    return PrettyPrint(value);
   }
 
-  message += ": expected <" + MjsUnitToString(expected) +
-      "> found <" + MjsUnitToString(found) + ">";
-  throw new MjsUnitAssertionError(message);
-}
 
+  function fail(expectedText, found, name_opt) {
+    var message = "Fail" + "ure";
+    if (name_opt) {
+      // Fix this when we ditch the old test runner.
+      message += " (" + name_opt + ")";
+    }
 
-function deepObjectEquals(a, b) {
-  var aProps = [];
-  for (var key in a) {
-    aProps.push(key);
-  }
-  var bProps = [];
-  for (key in b) {
-    bProps.push(key);
+    message += ": expected <" + expectedText +
+        "> found <" + PrettyPrint(found) + ">";
+    throw new MjsUnitAssertionError(message);
   }
-  aProps.sort();
-  bProps.sort();
-  if (!deepEquals(aProps, bProps))
-    return false;
-  for (var i = 0; i < aProps.length; i++) {
-    if (!deepEquals(a[aProps[i]], b[aProps[i]]))
-      return false;
-  }
-  return true;
-}
 
 
-function deepEquals(a, b) {
-  if (a == b) {
-    // Check for -0.
-    if (a === 0 && b === 0) return (1 / a) === (1 / b);
-    return true;
-  }
-  if (typeof a == "number" && typeof b == "number" && isNaN(a) && isNaN(b)) {
-    return true;
-  }
-  if (a == null || b == null) return false;
-  var aClass = classOf(a);
-  var bClass = classOf(b);
-  if (aClass === "RegExp" || bClass === "RegExp") {
-    return (aClass === bClass) && (a.toString() === b.toString());
-  }
-  if ((typeof a) !== 'object' || (typeof b) !== 'object' ||
-      (a === null) || (b === null))
-    return false;
-  if (aClass === "Array") {
-    if (bClass !== "Array")
-      return false;
-    if (a.length != b.length)
+  function deepObjectEquals(a, b) {
+    var aProps = Object.keys(a);
+    aProps.sort();
+    var bProps = Object.keys(b);
+    bProps.sort();
+    if (!deepEquals(aProps, bProps)) {
       return false;
-    for (var i = 0; i < a.length; i++) {
-      if (i in a) {
-        if (!(i in b) || !(deepEquals(a[i], b[i])))
-          return false;
-      } else if (i in b) {
+    }
+    for (var i = 0; i < aProps.length; i++) {
+      if (!deepEquals(a[aProps[i]], b[aProps[i]])) {
         return false;
       }
     }
     return true;
-  } else if (bClass == "Array") {
-    return false;
-  } else {
-    return deepObjectEquals(a, b);
   }
-}
 
 
-function assertSame(expected, found, name_opt) {
-  if (found !== expected) {
-    fail(expected, found, name_opt);
+  function deepEquals(a, b) {
+    if (a === b) {
+      // Check for -0.
+      if (a === 0) return (1 / a) === (1 / b);
+      return true;
+    }
+    if (typeof a != typeof b) return false;
+    if (typeof a == "number") return isNaN(a) && isNaN(b);
+    if (typeof a !== "object" && typeof a !== "function") return false;
+    // Neither a nor b is primitive.
+    var objectClass = classOf(a);
+    if (objectClass !== classOf(b)) return false;
+    if (objectClass === "RegExp") {
+      // For RegExp, just compare pattern and flags using its toString.
+      return (a.toString() === b.toString());
+    }
+    // Functions are only identical to themselves.
+    if (objectClass === "Function") return false;
+    if (objectClass === "Array") {
+      var elementCount = 0;
+      if (a.length != b.length) {
+        return false;
+      }
+      for (var i = 0; i < a.length; i++) {
+        if (!deepEquals(a[i], b[i])) return false;
+      }
+      return true;
+    }
+    if (objectClass == "String" || objectClass == "Number" ||
+      objectClass == "Boolean" || objectClass == "Date") {
+      if (a.valueOf() !== b.valueOf()) return false;
+    }
+    return deepObjectEquals(a, b);
   }
-}
 
 
-function assertEquals(expected, found, name_opt) {
-  if (!deepEquals(found, expected)) {
-    fail(expected, found, name_opt);
-  }
-}
+  assertSame = function assertSame(expected, found, name_opt) {
+    if (found === expected) {
+      if (expected !== 0 || (1 / expected) == (1 / found)) return;
+    } else if (isNaN(expected) && isNaN(found)) {
+      return;
+    }
+    fail(PrettyPrint(expected), found, name_opt);
+  };
 
 
-function assertArrayEquals(expected, found, name_opt) {
-  var start = "";
-  if (name_opt) {
-    start = name_opt + " - ";
-  }
-  assertEquals(expected.length, found.length, start + "array length");
-  if (expected.length == found.length) {
-    for (var i = 0; i < expected.length; ++i) {
-      assertEquals(expected[i], found[i], start + "array element at index " + i);
+  assertEquals = function assertEquals(expected, found, name_opt) {
+    if (!deepEquals(found, expected)) {
+      fail(PrettyPrint(expected), found, name_opt);
     }
-  }
-}
+  };
 
 
-function assertTrue(value, name_opt) {
-  assertEquals(true, value, name_opt);
-}
+  assertArrayEquals = function assertArrayEquals(expected, found, name_opt) {
+    var start = "";
+    if (name_opt) {
+      start = name_opt + " - ";
+    }
+    assertEquals(expected.length, found.length, start + "array length");
+    if (expected.length == found.length) {
+      for (var i = 0; i < expected.length; ++i) {
+        assertEquals(expected[i], found[i],
+                     start + "array element at index " + i);
+      }
+    }
+  };
 
 
-function assertFalse(value, name_opt) {
-  assertEquals(false, value, name_opt);
-}
+  assertPropertiesEqual = function assertPropertiesEqual(expected, found,
+                                                         name_opt) {
+    // Check properties only.
+    if (!deepObjectEquals(expected, found)) {
+      fail(expected, found, name_opt);
+    }
+  };
 
 
-function assertNaN(value, name_opt) {
-  if (!isNaN(value)) {
-    fail("NaN", value, name_opt);
-  }
-}
+  assertToStringEquals = function assertToStringEquals(expected, found,
+                                                       name_opt) {
+    if (expected != String(found)) {
+      fail(expected, found, name_opt);
+    }
+  };
 
 
-function assertNull(value, name_opt) {
-  if (value !== null) {
-    fail("null", value, name_opt);
-  }
-}
+  assertTrue = function assertTrue(value, name_opt) {
+    assertEquals(true, value, name_opt);
+  };
 
 
-function assertNotNull(value, name_opt) {
-  if (value === null) {
-    fail("not null", value, name_opt);
-  }
-}
+  assertFalse = function assertFalse(value, name_opt) {
+    assertEquals(false, value, name_opt);
+  };
 
 
-function assertThrows(code, type_opt, cause_opt) {
-  var threwException = true;
-  try {
-    if (typeof code == 'function') {
-      code();
-    } else {
-      eval(code);
+  assertNull = function assertNull(value, name_opt) {
+    if (value !== null) {
+      fail("null", value, name_opt);
     }
-    threwException = false;
-  } catch (e) {
-    if (typeof type_opt == 'function')
-      assertInstanceof(e, type_opt);
-    if (arguments.length >= 3)
-      assertEquals(e.type, cause_opt);
-    // Do nothing.
-  }
-  if (!threwException) assertTrue(false, "did not throw exception");
-}
+  };
 
 
-function assertInstanceof(obj, type) {
-  if (!(obj instanceof type)) {
-    assertTrue(false, "Object <" + obj + "> is not an instance of <" + type + ">");
-  }
-}
+  assertNotNull = function assertNotNull(value, name_opt) {
+    if (value === null) {
+      fail("not null", value, name_opt);
+    }
+  };
 
 
-function assertDoesNotThrow(code) {
-  try {
-    if (typeof code == 'function') {
-      code();
-    } else {
-      eval(code);
+  assertThrows = function assertThrows(code, type_opt, cause_opt) {
+    var threwException = true;
+    try {
+      if (typeof code == 'function') {
+        code();
+      } else {
+        eval(code);
+      }
+      threwException = false;
+    } catch (e) {
+      if (typeof type_opt == 'function') {
+        assertInstanceof(e, type_opt);
+      }
+      if (arguments.length >= 3) {
+        assertEquals(e.type, cause_opt);
+      }
+      // Success.
+      return;
     }
-  } catch (e) {
-    assertTrue(false, "threw an exception: " + (e.message || e));
-  }
-}
+    throw new MjsUnitAssertionError("Did not throw exception");
+  };
 
 
-function assertUnreachable(name_opt) {
-  // Fix this when we ditch the old test runner.
-  var message = "Fail" + "ure: unreachable";
-  if (name_opt) {
-    message += " - " + name_opt;
-  }
-  throw new MjsUnitAssertionError(message);
-}
+  assertInstanceof = function assertInstanceof(obj, type) {
+    if (!(obj instanceof type)) {
+      var actualTypeName = null;
+      var actualConstructor = Object.prototypeOf(obj).constructor;
+      if (typeof actualConstructor == "function") {
+        actualTypeName = actualConstructor.name || String(actualConstructor);
+      }
+      fail("Object <" + PrettyPrint(obj) + "> is not an instance of <" +
+               (type.name || type) + ">" +
+               (actualTypeName ? " but of < " + actualTypeName + ">" : ""));
+    }
+  };
+
+
+   assertDoesNotThrow = function assertDoesNotThrow(code, name_opt) {
+    try {
+      if (typeof code == 'function') {
+        code();
+      } else {
+        eval(code);
+      }
+    } catch (e) {
+      fail("threw an exception: ", e.message || e, name_opt);
+    }
+  };
+
+  assertUnreachable = function assertUnreachable(name_opt) {
+    // Fix this when we ditch the old test runner.
+    var message = "Fail" + "ure: unreachable";
+    if (name_opt) {
+      message += " - " + name_opt;
+    }
+    throw new MjsUnitAssertionError(message);
+  };
+
+})();
+