feat: Support for local files

index.js

@@ -12,6 +12,8 @@ const osFilterObj = importLazy('os-filter-obj');
 
 const statAsync = pify(fs.stat);
 const chmodAsync = pify(fs.chmod);
+const lstatAsync = pify(fs.lstat);
+const copyFileAsync = pify(fs.copyFile);
 
 /**
  * Initialize a new `BinWrapper`
@@ -30,6 +32,29 @@ module.exports = class BinWrapper {
 		}
 	}
 
+	/**
+	 * Get or set local files to use before download
+	 *
+	 * @param {String} src
+	 * @param {String} os
+	 * @param {String} arch
+	 * @api public
+	 */
+	localSrc(src, os, arch) {
+		if (arguments.length === 0) {
+			return this._localSrc;
+		}
+
+		this._localSrc = this._localSrc || [];
+		this._localSrc.push({
+			url: src,
+			os,
+			arch
+		});
+
+		return this;
+	}
+
 	/**
 	 * Get or set files to download
 	 *
@@ -151,13 +176,44 @@ module.exports = class BinWrapper {
 	findExisting() {
 		return statAsync(this.path()).catch(error => {
 			if (error && error.code === 'ENOENT') {
-				return this.download();
+				return this.copyLocal().catch(() => this.download());
 			}
 
 			return Promise.reject(error);
 		});
 	}
 
+	/**
+	 * Copying local files
+	 *
+	 * @api private
+	 */
+	copyLocal() {
+		const files = osFilterObj(this.localSrc() || []);
+		const urls = [];
+
+		if (files.length === 0) {
+			return Promise.reject(new Error('No binary found matching your system. It\'s probably not supported.'));
+		}
+
+		files.forEach(file => urls.push(file.url));
+
+		return Promise.all(urls.map(url => lstatAsync(url).then(stats => {
+			if (stats.isDirectory()) {
+				return Promise.reject(new Error('Local source path is a directory.'));
+			}
+			if (stats.isSymbolicLink()) {
+				return Promise.reject(new Error('Local source path is a symbolic link.'));
+			}
+			if (!stats.isFile()) {
+				return Promise.reject(new Error('Local source path is not a file.'));
+			}
+
+			return copyFileAsync(url, path.join(this.dest(), path.basename(url)))
+			.then(() => chmodAsync(path.join(this.dest(), fileName), 0o755));
+		})));
+	}
+
 	/**
 	 * Download files
 	 *

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "bin-wrapper",
-	"version": "4.1.0",
+	"version": "4.2.0",
 	"description": "Binary wrapper that makes your programs seamlessly available as local dependencies",
 	"license": "MIT",
 	"repository": "kevva/bin-wrapper",

readme.md

@@ -17,6 +17,9 @@ const BinWrapper = require('bin-wrapper');
 
 const base = 'https://github.com/imagemin/gifsicle-bin/raw/master/vendor';
 const bin = new BinWrapper()
+	.localSrc(`vendor/macos/gifsicle`, 'darwin')
+	.localSrc(`vendor/linux/x64/gifsicle`, 'linux', 'x64')
+	.localSrc(`vendor/win/x64/gifsicle.exe`, 'win32', 'x64')
 	.src(`${base}/macos/gifsicle`, 'darwin')
 	.src(`${base}/linux/x64/gifsicle`, 'linux', 'x64')
 	.src(`${base}/win/x64/gifsicle.exe`, 'win32', 'x64')
@@ -84,13 +87,23 @@ Type: `string`
 
 Tie the source to a specific arch.
 
+### .localSrc(filepath, [os], [arch])
+
+Same as `.src()`, but adds a local source to copy, before trying any downloads.
+
+#### filepath
+
+Type: `string`
+
+Accepts a filepath pointing to a local file.
+
 ### .dest(destination)
 
 #### destination
 
 Type: `string`
 
-Accepts a path which the files will be downloaded to.
+Accepts a path which the files will be copied/downloaded to.
 
 ### .use(binary)