Merge pull request #245 from XmiliaH/per-script-compiler

Allow to specify a compiler per VMScript.
patriksimek · Sep 14, 2019 · 78f8be5 · 78f8be5
2 parents 284a518 + d674d43
commit 78f8be5
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Showing 2 changed files with 39 additions and 29 deletions.
diff --git a/lib/main.js b/lib/main.js
@@ -8,30 +8,42 @@ const pa = require('path');
 const {EventEmitter} = require('events');
 const {INSPECT_MAX_BYTES} = require('buffer');
 
-const _compileToJS = function compileToJS(code, compiler, filename) {
-	if ('function' === typeof compiler) return compiler(code, filename);
+const COFFEE_SCRIPT_COMPILER = {compiler: null};
+function getCoffeeScriptCompiler() {
+	if (!COFFEE_SCRIPT_COMPILER.compiler) {
+		try {
+			const coffeeScript = require('coffee-script');
+			COFFEE_SCRIPT_COMPILER.compiler = (code, filename) => {
+				return coffeeScript.compile(code, {header: false, bare: true});
+			};
+		} catch (e) {
+			throw new VMError('Coffee-Script compiler is not installed.');
+		}
+	}
+	return COFFEE_SCRIPT_COMPILER.compiler;
+}
 
+function jsCompiler(code, filename) {
+	return code;
+}
+
+function lookupCompiler(compiler) {
+	if ('function' === typeof compiler) return compiler;
 	switch (compiler) {
 		case 'coffeescript':
 		case 'coffee-script':
 		case 'cs':
 		case 'text/coffeescript':
-			try {
-				return require('coffee-script').compile(code, {header: false, bare: true});
-			} catch (ex) {
-				throw new VMError('Coffee-Script compiler is not installed.');
-			}
-
+			return getCoffeeScriptCompiler();
 		case 'javascript':
 		case 'java-script':
 		case 'js':
 		case 'text/javascript':
-			return code;
-
+			return jsCompiler;
 		default:
 			throw new VMError(`Unsupported compiler '${compiler}'.`);
 	}
-};
+}
 
 /**
  * Class Script
@@ -51,12 +63,14 @@ class VMScript {
 
 	constructor(code, filename, options) {
 		this._code = String(code);
-		this.filename = filename || 'vm.js';
 		this.options = options || {};
+		this.filename = filename || this.options.filename || 'vm.js';
 		this._prefix = '';
 		this._suffix = '';
 		this._compiledVM = null;
 		this._compiledNodeVM = null;
+		this._compiler = lookupCompiler(this.options.compiler || 'javascript');
+		this._unresolvedFilename = this.options.filename || this.filename;
 	}
 
 	/**
@@ -120,7 +134,7 @@ class VMScript {
 	_compileVM() {
 		if (this._compiledVM) return this;
 
-		this._compiledVM = new vm.Script(this._prefix + this._code + this._suffix, {
+		this._compiledVM = new vm.Script(this._compiler(this._prefix + this._code + this._suffix, this._unresolvedFilename), {
 			filename: this.filename,
 			displayErrors: false,
 			lineOffset: this.options.lineOffset || 0,
@@ -139,7 +153,7 @@ class VMScript {
 		if (this._compiledNodeVM) return this;
 
 		this._compiledNodeVM = new vm.Script('(function (exports, require, module, __filename, __dirname) { ' +
-				this._prefix + this._code + this._suffix + '\n})', {
+				this._compiler(this._prefix + this._code + this._suffix, this._unresolvedFilename) + '\n})', {
 			filename: this.filename,
 			displayErrors: false,
 			lineOffset: this.options.lineOffset || 0,
@@ -183,7 +197,7 @@ class VM extends EventEmitter {
 		this.options = {
 			timeout: options.timeout,
 			sandbox: options.sandbox,
-			compiler: options.compiler || 'javascript',
+			compiler: lookupCompiler(options.compiler || 'javascript'),
 			eval: options.eval === false ? false : true,
 			wasm: options.wasm === false ? false : true
 		};
@@ -281,15 +295,12 @@ class VM extends EventEmitter {
 	 * Run the code in VM.
 	 *
 	 * @param {String} code Code to run.
+	 * @param {String} [filename] Filename that shows up in any stack traces produced from this script.
 	 * @return {*} Result of executed code.
 	 */
 
-	run(code) {
-		if (this.options.compiler !== 'javascript') {
-			code = _compileToJS(code, this.options.compiler);
-		}
-
-		const script = code instanceof VMScript ? code : new VMScript(code);
+	run(code, filename) {
+		const script = code instanceof VMScript ? code : new VMScript(code, filename, {compiler: this.options.compiler});
 		script._compileVM();
 
 		try {
@@ -330,7 +341,7 @@ class NodeVM extends EventEmitter {
 			sandbox: options.sandbox,
 			console: options.console || 'inherit',
 			require: options.require || false,
-			compiler: options.compiler || 'javascript',
+			compiler: lookupCompiler(options.compiler || 'javascript'),
 			eval: options.eval === false ? false : true,
 			wasm: options.wasm === false ? false : true,
 			nesting: options.nesting || false,
@@ -495,26 +506,23 @@ class NodeVM extends EventEmitter {
 	 */
 
 	run(code, filename) {
-		if (this.options.compiler !== 'javascript') {
-			code = _compileToJS(code, this.options.compiler, filename);
-		}
-
 		let dirname;
 		let returned;
+		let resolvedFilename;
 
 		if (filename) {
-			filename = pa.resolve(filename);
+			resolvedFilename = pa.resolve(filename);
 			dirname = pa.dirname(filename);
 		} else {
-			filename = null;
+			resolvedFilename = null;
 			dirname = null;
 		}
 
 		const module = SCRIPT_CACHE.exp._compiledVM.runInContext(this._context, {
 			displayErrors: false
 		});
 
-		const script = code instanceof VMScript ? code : new VMScript(code, filename);
+		const script = code instanceof VMScript ? code : new VMScript(code, resolvedFilename, {compiler: this.options.compiler, filename});
 		script._compileNodeVM();
 
 		try {

diff --git a/test/vm.js b/test/vm.js
@@ -316,6 +316,8 @@ describe('VM', () => {
 				return true;
 			});
 		}
+		assert.throws(() => new VM({compiler: 'nonexistant'}), /Unsupported compiler/);
+		assert.throws(() => new VMScript('', '', {compiler: 'nonexistant'}), /Unsupported compiler/);
 	});
 
 	it('timeout', () => {