feat: integer/coerce

README.md

@@ -127,6 +127,20 @@ ensureFinite(12); // "12"
 ensureFinite(null); // Thrown TypeError: null is not a number
 ```
 
+#### Integer Number
+
+##### `integer/coerce`
+
+Follows [`finite/coerce`](#finitecoerce) additionally stripping decimal part from the number
+
+```javascript
+const coerceToInteger = require("type/integer/coerce");
+
+coerceToInteger("12.95"); // 12
+coerceToInteger(Infinity); // null
+coerceToInteger(null); // null
+```
+
 #### Object
 
 _Object_ is assumed to be any non-primitive JavaScript value

integer/coerce.js

@@ -0,0 +1,11 @@
+"use strict";
+
+var coerceToFinite = require("../finite/coerce");
+
+var abs = Math.abs, floor = Math.floor;
+
+module.exports = function (value) {
+	value = coerceToFinite(value);
+	if (!value) return value;
+	return (value > 0 ? 1 : -1) * floor(abs(value));
+};

test/integer/coerce.js

@@ -0,0 +1,43 @@
+"use strict";
+
+var assert          = require("chai").assert
+  , coerceToInteger = require("../../integer/coerce");
+
+describe("integer/coerce", function () {
+	it("Should coerce float to integer", function () {
+		assert.equal(coerceToInteger(123.123), 123);
+		assert.equal(coerceToInteger(123.823), 123);
+		assert.equal(coerceToInteger(-123.123), -123);
+		assert.equal(coerceToInteger(-123.823), -123);
+	});
+	it("Should coerce string", function () { assert.equal(coerceToInteger("12.123"), 12); });
+	it("Should coerce booleans", function () { assert.equal(coerceToInteger(true), 1); });
+	it("Should coerce number objects", function () {
+		assert.equal(coerceToInteger(new Number(343)), 343);
+	});
+	it("Should coerce objects", function () {
+		assert.equal(coerceToInteger({ valueOf: function () { return 23; } }), 23);
+	});
+
+	it("Should reject infinite number", function () {
+		assert.equal(coerceToInteger(Infinity), null);
+	});
+	it("Should reject NaN", function () { assert.equal(coerceToInteger(NaN), null); });
+
+	if (typeof Object.create === "function") {
+		it("Should not coerce objects with no number representation", function () {
+			assert.equal(coerceToInteger(Object.create(null)), null);
+		});
+	}
+
+	it("Should not coerce null", function () { assert.equal(coerceToInteger(null), null); });
+	it("Should not coerce undefined", function () {
+		assert.equal(coerceToInteger(undefined), null);
+	});
+
+	if (typeof Symbol === "function") {
+		it("Should not coerce symbols", function () {
+			assert.equal(coerceToInteger(Symbol("foo")), null);
+		});
+	}
+});