feat: safe-integer/coerce

README.md

@@ -192,6 +192,22 @@ ensureInteger(null); // Thrown TypeError: null is not a number
 
 ---
 
+#### Safe Integer Number
+
+##### `safe-integer/coerce`
+
+Follows [`integer/coerce`](#integercoerce) but returns `null` in place of values which are beyond `Number.MIN_SAFE_INTEGER` and `Number.MAX_SAFE_INTEGER` range.
+
+```javascript
+const coerceToSafeInteger = require("type/safe-integer/coerce");
+
+coerceToInteger("12.95"); // 12
+coerceToInteger(9007199254740992); // null
+coerceToInteger(null); // null
+```
+
+---
+
 ### Array
 
 The JavaScript _Array_ instance

safe-integer/coerce.js

@@ -0,0 +1,13 @@
+"use strict";
+
+var coerceToInteger = require("../integer/coerce");
+
+var MAX_SAFE_INTEGER = 9007199254740991, MIN_SAFE_INTEGER = -9007199254740991;
+
+module.exports = function (value) {
+	value = coerceToInteger(value);
+	if (!value) return value;
+	if (value > MAX_SAFE_INTEGER) return null;
+	if (value < MIN_SAFE_INTEGER) return null;
+	return value;
+};

test/integer/coerce.js

@@ -18,6 +18,12 @@ describe("integer/coerce", function () {
 	it("Should coerce objects", function () {
 		assert.equal(coerceToInteger({ valueOf: function () { return 23; } }), 23);
 	});
+	it("Should coerce number beyond Number.MAX_SAFE_INTEGER", function () {
+		assert.equal(coerceToInteger(9007199254740992), 9007199254740992);
+	});
+	it("Should coerce number beyond Number.MIN_SAFE_INTEGER", function () {
+		assert.equal(coerceToInteger(-9007199254740992), -9007199254740992);
+	});
 
 	it("Should reject infinite number", function () {
 		assert.equal(coerceToInteger(Infinity), null);

test/safe-integer/coerce.js

@@ -0,0 +1,49 @@
+"use strict";
+
+var assert              = require("chai").assert
+  , coerceToSafeInteger = require("../../safe-integer/coerce");
+
+describe("integer/coerce", function () {
+	it("Should coerce float to integer", function () {
+		assert.equal(coerceToSafeInteger(123.123), 123);
+		assert.equal(coerceToSafeInteger(123.823), 123);
+		assert.equal(coerceToSafeInteger(-123.123), -123);
+		assert.equal(coerceToSafeInteger(-123.823), -123);
+	});
+	it("Should coerce string", function () { assert.equal(coerceToSafeInteger("12.123"), 12); });
+	it("Should coerce booleans", function () { assert.equal(coerceToSafeInteger(true), 1); });
+	it("Should coerce number objects", function () {
+		assert.equal(coerceToSafeInteger(new Number(343)), 343);
+	});
+	it("Should coerce objects", function () {
+		assert.equal(coerceToSafeInteger({ valueOf: function () { return 23; } }), 23);
+	});
+	it("Should reject infinite number", function () {
+		assert.equal(coerceToSafeInteger(Infinity), null);
+	});
+	it("Should reject number beyond Number.MAX_SAFE_INTEGER", function () {
+		assert.equal(coerceToSafeInteger(9007199254740992), null);
+	});
+	it("Should reject number beyond Number.MIN_SAFE_INTEGER", function () {
+		assert.equal(coerceToSafeInteger(-9007199254740992), null);
+	});
+
+	it("Should reject NaN", function () { assert.equal(coerceToSafeInteger(NaN), null); });
+
+	if (typeof Object.create === "function") {
+		it("Should not coerce objects with no number representation", function () {
+			assert.equal(coerceToSafeInteger(Object.create(null)), null);
+		});
+	}
+
+	it("Should not coerce null", function () { assert.equal(coerceToSafeInteger(null), null); });
+	it("Should not coerce undefined", function () {
+		assert.equal(coerceToSafeInteger(undefined), null);
+	});
+
+	if (typeof Symbol === "function") {
+		it("Should not coerce symbols", function () {
+			assert.equal(coerceToSafeInteger(Symbol("foo")), null);
+		});
+	}
+});