EAGLESIX-2651: Size: fix expr and tests

lib/pipeline/expressions/SizeExpression.js

@@ -6,36 +6,25 @@
  * @class SizeExpression
  * @namespace mungedb-aggregate.pipeline.expressions
  * @module mungedb-aggregate
+ * @extends mungedb-aggregate.pipeline.FixedArityExpressionT
  * @constructor
- **/
+ */
 var SizeExpression = module.exports = function SizeExpression() {
+	if (arguments.length !== 0) throw new Error(klass.name + ": args expected: value");
 	base.call(this);
-}, klass = SizeExpression,
-	FixedArityExpression = require("./FixedArityExpressionT")(klass, 1),
-	base = FixedArityExpression,
-	proto = klass.prototype = Object.create(base.prototype, {
-		constructor: {
-			value: klass
-		}
-	});
+}, klass = SizeExpression, base = require("./FixedArityExpressionT")(SizeExpression, 1), proto = klass.prototype = Object.create(base.prototype, {constructor:{value:klass}});
 
-// DEPENDENCIES
 var Value = require("../Value"),
 	Expression = require("./Expression");
 
-// PROTOTYPE MEMBERS
-proto.getOpName = function getOpName() {
-	return "$size";
-};
-
-/**
- * Takes an array and return the size.
- **/
 proto.evaluateInternal = function evaluateInternal(vars) {
 	var array = this.operands[0].evaluateInternal(vars);
-	if (array instanceof Date) throw new Error("$size does not support dates; code 16376");
+	if (!(array instanceof Array)) throw new Error("The argument to $size must be an Array but was of type" + Value.getType(array) + "; uassert code 16376");
 	return array.length;
 };
 
-/** Register Expression */
 Expression.registerExpression("$size", base.parse);
+
+proto.getOpName = function getOpName() {
+	return "$size";
+};

test/lib/pipeline/expressions/SizeExpression.js

@@ -1,46 +1,50 @@
 "use strict";
+
 var assert = require("assert"),
-		SizeExpression = require("../../../../lib/pipeline/expressions/SizeExpression"),
-		Expression = require("../../../../lib/pipeline/expressions/Expression");
+	SizeExpression = require("../../../../lib/pipeline/expressions/SizeExpression"),
+	Expression = require("../../../../lib/pipeline/expressions/Expression");
 
+// Mocha one-liner to make these tests self-hosted
+if(!module.parent)return(require.cache[__filename]=null,(new(require("mocha"))({ui:"exports",reporter:"spec",grep:process.env.TEST_GREP})).addFile(__filename).run(process.exit));
 
-module.exports = {
+exports.SizeExpression = {
 
-		"SizeExpression": {
+	"constructor()": {
 
-				"constructor()": {
+		"should construct instance": function testConstructor() {
+			assert(new SizeExpression() instanceof SizeExpression);
+			assert(new SizeExpression() instanceof Expression);
+		},
 
-						"should throw Error when constructing without args": function testConstructor() {
-								assert.throws(function() {
-										new SizeExpression();
-								});
-						}
+		"should error if given args": function testConstructor() {
+			assert.throws(function() {
+				new SizeExpression("bad stuff");
+			});
+		},
 
-				},
+	},
 
-				"#getOpName()": {
+	"#evaluate()": {
 
-						"should return the correct op name; $size": function testOpName() {
-								assert.equal(new SizeExpression("test").getOpName(), "$size");
-						}
+		"should return the size": function testSize() {
+			assert.deepEqual(
+				Expression.parseOperand({$size: ["$a"]})
+					.evaluate({
+						a: [{a:1},{b:2}],
+						b: [{c:3}]
+					}),
+				[{a:1},{b:2}]
+			);
+		},
 
-				},
+	},
 
-				"#evaluateInternal()": {
+	"#getOpName()": {
 
-						// New test not working
-						"should return the size": function testSize() {
-								assert.strictEqual(Expression.parseOperand({
-										$size: ["$a"]
-								}).evaluateInternal({
-										a: [{a:1},{b:2}],
-										b: [{c:3}]
-								}), 4);
-						}
-				}
+		"should return the correct op name; $size": function testOpName() {
+			assert.equal(new SizeExpression().getOpName(), "$size");
+		},
 
-		}
+	},
 
 };
-
-if (!module.parent)(new(require("mocha"))()).ui("exports").reporter("spec").addFile(__filename).run(process.exit);