Change the public API to use Promises (#66)

Author: realityking

index.js

@@ -1,13 +1,16 @@
 'use strict';
 const fs = require('fs');
 const path = require('path');
+const pify = require('pify');
 const importLazy = require('import-lazy')(require);
 
 const binCheck = importLazy('bin-check');
 const binVersionCheck = importLazy('bin-version-check');
 const download = importLazy('download');
 const osFilterObj = importLazy('os-filter-obj');
 
+const statAsync = pify(fs.stat);
+
 /**
  * Initialize a new `BinWrapper`
  *
@@ -106,39 +109,27 @@ module.exports = class BinWrapper {
 	 * Run
 	 *
 	 * @param {Array} cmd
-	 * @param {Function} cb
 	 * @api public
 	 */
-	run(cmd, cb) {
-		if (typeof cmd === 'function' && !cb) {
-			cb = cmd;
-			cmd = ['--version'];
-		}
-
-		this.findExisting(err => {
-			if (err) {
-				cb(err);
-				return;
-			}
-
-			if (this.options.skipCheck) {
-				cb();
-				return;
-			}
+	run(cmd = ['--version']) {
+		return this.findExisting()
+			.then(() => {
+				if (this.options.skipCheck) {
+					return;
+				}
 
-			this.runCheck(cmd, cb);
-		});
+				return this.runCheck(cmd);
+			});
 	}
 
 	/**
 	 * Run binary check
 	 *
 	 * @param {Array} cmd
-	 * @param {Function} cb
 	 * @api private
 	 */
-	runCheck(cmd, cb) {
-		binCheck(this.path(), cmd)
+	runCheck(cmd) {
+		return binCheck(this.path(), cmd)
 			.then(works => {
 				if (!works) {
 					throw new Error(`The \`${this.path()}\` binary doesn't seem to work correctly`);
@@ -149,56 +140,44 @@ module.exports = class BinWrapper {
 				}
 
 				return Promise.resolve();
-			})
-			.then(() => cb())
-			.catch(err => cb(err));
+			});
 	}
 
 	/**
 	 * Find existing files
 	 *
-	 * @param {Function} cb
 	 * @api private
 	 */
-	findExisting(cb) {
-		fs.stat(this.path(), err => {
-			if (err && err.code === 'ENOENT') {
-				this.download(cb);
-				return;
-			}
-
-			if (err) {
-				cb(err);
-				return;
-			}
-
-			cb();
-		});
+	findExisting() {
+		return statAsync(this.path())
+			.catch(err => {
+				if (err && err.code === 'ENOENT') {
+					return this.download();
+				}
+
+				return Promise.reject(err);
+			});
 	}
 
 	/**
 	 * Download files
 	 *
-	 * @param {Function} cb
 	 * @api private
 	 */
-	download(cb) {
+	download() {
 		const files = osFilterObj(this.src() || []);
 		const urls = [];
 
 		if (files.length === 0) {
-			cb(new Error('No binary found matching your system. It\'s probably not supported.'));
-			return;
+			return Promise.reject(new Error('No binary found matching your system. It\'s probably not supported.'));
 		}
 
 		files.forEach(file => urls.push(file.url));
 
-		Promise.all(urls.map(url => download(url, this.dest(), {
+		return Promise.all(urls.map(url => download(url, this.dest(), {
 			extract: true,
 			mode: '755',
 			strip: this.options.strip
-		}))).then(() => {
-			cb();
-		});
+		})));
 	}
 };

package.json

@@ -29,13 +29,13 @@
 		"bin-version-check": "^3.0.0",
 		"download": "^7.1.0",
 		"import-lazy": "^3.1.0",
-		"os-filter-obj": "^2.0.0"
+		"os-filter-obj": "^2.0.0",
+		"pify": "^3.0.0"
 	},
 	"devDependencies": {
 		"ava": "*",
 		"nock": "^9.4.2",
 		"path-exists": "^3.0.0",
-		"pify": "^3.0.0",
 		"rimraf": "^2.6.2",
 		"tempy": "^0.2.1",
 		"xo": "*"

readme.md

@@ -24,9 +24,10 @@ const bin = new BinWrapper()
 	.use(process.platform === 'win32' ? 'gifsicle.exe' : 'gifsicle')
 	.version('>=1.71');
 
-bin.run(['--version'], err => {
-	console.log('gifsicle is working');
-});
+bin.run(['--version'])
+  .then(()) => {
+	  console.log('gifsicle is working');
+  });
 ```
 
 Get the path to your binary with `bin.path()`:
@@ -110,7 +111,7 @@ Type: `string`
 Define a [semver range](https://github.com/isaacs/node-semver#ranges) to check
 the binary against.
 
-### .run([arguments], callback)
+### .run([arguments])
 
 Runs the search for the binary. If no binary is found it will download the file
 using the URL provided in `.src()`.
@@ -123,13 +124,6 @@ Default: `['--version']`
 Command to run the binary with. If it exits with code `0` it means that the
 binary is working.
 
-#### callback(err)
-
-Type: `Function`
-
-Returns nothing but a possible error.
-
-
 ## License
 
 MIT © [Kevin Mårtensson](http://kevinmartensson.com)

test.js

@@ -67,7 +67,7 @@ test('verify that a binary is working', async t => {
 		.dest(tempy.directory())
 		.use(process.platform === 'win32' ? 'gifsicle.exe' : 'gifsicle');
 
-	await pify(bin.run.bind(bin))();
+	await bin.run();
 	t.true(await pathExists(bin.path()));
 	await rimrafP(bin.dest());
 });
@@ -79,7 +79,7 @@ test('meet the desired version', async t => {
 		.use(process.platform === 'win32' ? 'gifsicle.exe' : 'gifsicle')
 		.version('>=1.71');
 
-	await pify(bin.run.bind(bin))();
+	await bin.run();
 	t.true(await pathExists(bin.path()));
 	await rimrafP(bin.dest());
 });
@@ -92,7 +92,7 @@ test('download files even if they are not used', async t => {
 		.dest(tempy.directory())
 		.use(process.platform === 'win32' ? 'gifsicle.exe' : 'gifsicle');
 
-	await pify(bin.run.bind(bin))();
+	await bin.run();
 	const files = await fsP.readdirSync(bin.dest());
 
 	t.is(files.length, 3);
@@ -109,7 +109,7 @@ test('skip running binary check', async t => {
 		.dest(tempy.directory())
 		.use(process.platform === 'win32' ? 'gifsicle.exe' : 'gifsicle');
 
-	await pify(bin.run.bind(bin))(['--shouldNotFailAnyway']);
+	await bin.run(['--shouldNotFailAnyway']);
 	t.true(await pathExists(bin.path()));
 	await rimrafP(bin.dest());
 });
@@ -119,5 +119,5 @@ test('error if no binary is found and no source is provided', async t => {
 		.dest(tempy.directory())
 		.use(process.platform === 'win32' ? 'gifsicle.exe' : 'gifsicle');
 
-	await t.throws(pify(bin.run.bind(bin))(), 'No binary found matching your system. It\'s probably not supported.');
+	await t.throws(bin.run(), 'No binary found matching your system. It\'s probably not supported.');
 });