Add isBoolean (#53)

docs/is.md

@@ -3,6 +3,7 @@
 Type checking utilities 
 
 - [isBN](#isbn) Tests for a `BN` object instance.
+- [isBoolean](#isboolean) Tests for a boolean value.
 - [isBuffer](#isbuffer) Tests for a `Buffer` object instance.
 - [isError](#iserror) Tests for a `Error` object instance.
 - [isFunction](#isfunction) Tests for a `function`.
@@ -34,6 +35,23 @@ import { isBN } from '@polkadot/util';
 console.log('isBN', isBN(new BN(1))); // => true
 ```
 
+## isBoolean
+
+Tests for a boolean value. 
+
+```js
+isBoolean (value: any): boolean
+```
+
+
+Checks to see if the input value is a JavaScript boolean.
+
+```js
+import { isBoolean } from '@polkadot/util';
+
+isBoolean(false); // => true
+```
+
 ## isBuffer
 
 Tests for a `Buffer` object instance. 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@polkadot/util",
-  "version": "0.9.3",
+  "version": "0.10.0",
   "description": "A collection of useful utilities for @polkadot",
   "main": "index.js",
   "keywords": [
@@ -29,8 +29,8 @@
     "test": "jest --coverage"
   },
   "devDependencies": {
-    "@polkadot/api-jsonrpc": "^0.6.5",
-    "@polkadot/dev": "^0.13.4"
+    "@polkadot/api-jsonrpc": "^0.6.7",
+    "@polkadot/dev": "^0.13.5"
   },
   "dependencies": {
     "babel-runtime": "^6.26.0",

src/is/boolean.js

@@ -0,0 +1,17 @@
+// ISC, Copyright 2017 Jaco Greeff
+// @flow
+
+/**
+  @name isBoolean
+  @signature isBoolean (value: any): boolean
+  @summary Tests for a boolean value.
+  @description
+    Checks to see if the input value is a JavaScript boolean.
+  @example
+    import { isBoolean } from '@polkadot/util';
+
+    isBoolean(false); // => true
+*/
+module.exports = function isBoolean (value: any): boolean {
+  return typeof value === 'boolean';
+};

src/is/boolean.spec.js

@@ -0,0 +1,23 @@
+// ISC, Copyright 2017 Jaco Greeff
+
+const { isBoolean } = require('./index');
+
+describe('isBoolean', () => {
+  it('returns true on false', () => {
+    expect(
+      isBoolean(false)
+    ).toEqual(true);
+  });
+
+  it('returns true on true', () => {
+    expect(
+      isBoolean(true)
+    ).toEqual(true);
+  });
+
+  it('returns false on invalid booleans', () => {
+    expect(
+      isBoolean('notABool')
+    ).toEqual(false);
+  });
+});

src/is/index.js

@@ -3,6 +3,7 @@
 
 const isBN = require('./bn');
 const isBuffer = require('./buffer');
+const isBoolean = require('./boolean');
 const isError = require('./error');
 const isFunction = require('./function');
 const isHex = require('./hex');
@@ -20,6 +21,7 @@ const isUndefined = require('./undefined');
 */
 module.exports = {
   isBN,
+  isBoolean,
   isBuffer,
   isError,
   isFunction,

yarn.lock

@@ -54,15 +54,15 @@
     lodash "^4.2.0"
     to-fast-properties "^2.0.0"
 
-"@polkadot/api-jsonrpc@^0.6.5":
-  version "0.6.5"
-  resolved "https://registry.yarnpkg.com/@polkadot/api-jsonrpc/-/api-jsonrpc-0.6.5.tgz#fa78923847e17e0c50c431b1935478e226284e1d"
+"@polkadot/api-jsonrpc@^0.6.7":
+  version "0.6.7"
+  resolved "https://registry.yarnpkg.com/@polkadot/api-jsonrpc/-/api-jsonrpc-0.6.7.tgz#5be45086d4c1d5f396bbd5cbcc17dcb8663f709b"
   dependencies:
     babel-runtime "^6.26.0"
 
-"@polkadot/dev@^0.13.4":
-  version "0.13.4"
-  resolved "https://registry.yarnpkg.com/@polkadot/dev/-/dev-0.13.4.tgz#beaa45da1655f8335b4a8294db3803f95cd3cc4e"
+"@polkadot/dev@^0.13.5":
+  version "0.13.5"
+  resolved "https://registry.yarnpkg.com/@polkadot/dev/-/dev-0.13.5.tgz#01dc2e720d5f9a4133a944fb42ae44623cd02880"
   dependencies:
     babel-cli "^6.26.0"
     babel-core "^6.26.0"