#172 - Support alternative fs implementations.

README.md

@@ -95,6 +95,10 @@ Plugins are executed in a pipeline, and register which event they should be exec
 
 ## Tests
 
+```
+npm install yarn -g
+```
+
 ``` javascript
 npm test
 ```

lib/NodeJsInputFileSystem.js

@@ -4,11 +4,30 @@
 */
 "use strict";
 
-const fs = require("graceful-fs");
+const defaultFs = require("graceful-fs");
+
+const fsMethods = [
+	"stat",
+	"statSync",
+	"readFile",
+	"readFileSync",
+	"readlink",
+	"readlinkSync"
+];
 
 class NodeJsInputFileSystem {
+	constructor(fs) {
+		var fileSystem = (this.fs = fs || defaultFs);
+		for (const key of fsMethods) {
+			Object.defineProperty(this, key, {
+				configurable: true,
+				writable: true,
+				value: fileSystem[key].bind(fileSystem)
+			});
+		}
+	}
 	readdir(path, callback) {
-		fs.readdir(path, (err, files) => {
+		this.fs.readdir(path, (err, files) => {
 			callback(
 				err,
 				files &&
@@ -20,7 +39,7 @@ class NodeJsInputFileSystem {
 	}
 
 	readdirSync(path) {
-		const files = fs.readdirSync(path);
+		const files = this.fs.readdirSync(path);
 		return (
 			files &&
 			files.map(file => {
@@ -30,21 +49,4 @@ class NodeJsInputFileSystem {
 	}
 }
 
-const fsMethods = [
-	"stat",
-	"statSync",
-	"readFile",
-	"readFileSync",
-	"readlink",
-	"readlinkSync"
-];
-
-for (const key of fsMethods) {
-	Object.defineProperty(NodeJsInputFileSystem.prototype, key, {
-		configurable: true,
-		writable: true,
-		value: fs[key].bind(fs)
-	});
-}
-
 module.exports = NodeJsInputFileSystem;

package.json

@@ -30,7 +30,8 @@
     "lint-staged": "^8.1.0",
     "mocha": "^2.3.4",
     "prettier": "^1.15.2",
-    "should": "^8.0.2"
+    "should": "^8.0.2",
+    "memfs": "^2.14.1"
   },
   "engines": {
     "node": ">=6.9.0"

test/NodeJsInputFileSystem.js

@@ -0,0 +1,67 @@
+var nodeJsInputFileSystem = require("../lib/NodeJsInputFileSystem");
+var should = require("should");
+
+describe("NodeJsInputFileSystem", function() {
+	this.timeout(3000);
+	beforeEach(function() {});
+	afterEach(function() {
+		//fs.purge();
+	});
+
+	it("shoud not require fs argument in constructor", function(done) {
+		var nodeFs = new nodeJsInputFileSystem();
+		should.exist(nodeFs);
+		done();
+	});
+
+	it("shoud allow fs argument in constructor", function(done) {
+		const volumeDir = "app";
+		//const unionfs = require("unionfs");
+		const memfs = require("memfs");
+		// mount files specified by "mockedFiles.js.amd" to "app" base directory.
+		const json = {
+			"./README.md": "1"
+		};
+		var vol = memfs.Volume.fromJSON(json, `${volumeDir}`);
+		//var ufs = unionfs.ufs.use(vol);
+		var nodeFs = new nodeJsInputFileSystem(vol);
+		should.exist(nodeFs);
+		done();
+	});
+
+	it("should call methods on fs provided", function(done) {
+		const volumeDir = "app";
+		//const unionfs = require("unionfs");
+		const memfs = require("memfs");
+		// mount files specified by "mockedFiles.js.amd" to "app" base directory.
+		const json = {
+			"./README.md": "1"
+		};
+		var vol = memfs.Volume.fromJSON(json, `${volumeDir}`);
+		var nodeFs = new nodeJsInputFileSystem(vol);
+
+		// stat
+		// statSync
+		nodeFs.stat("app/README.md", (err, stats) => {
+			should.exist(stats);
+			should.not.exist(err);
+			var statsSync = nodeFs.statSync("app/README.md");
+			should.exist(statsSync);
+			done();
+		});
+	});
+
+	it("should call methods on default fs when no fs provided", function(done) {
+		var nodeFs = new nodeJsInputFileSystem();
+
+		// stat
+		// statSync
+		nodeFs.stat("README.md", (err, stats) => {
+			should.exist(stats);
+			should.not.exist(err);
+			var statsSync = nodeFs.statSync("README.md");
+			should.exist(statsSync);
+			done();
+		});
+	});
+});