Replace function constructor with defineProperty

index.js

@@ -64,20 +64,6 @@ function convertDataDescriptorToAccessor (obj, prop, message) {
   return descriptor
 }
 
-/**
- * Create arguments string to keep arity.
- */
-
-function createArgumentsString (arity) {
-  var str = ''
-
-  for (var i = 0; i < arity; i++) {
-    str += ', arg' + i
-  }
-
-  return str.substr(2)
-}
-
 /**
  * Create stack string from stack.
  */
@@ -374,6 +360,20 @@ function formatLocation (callSite) {
     ':' + callSite[2]
 }
 
+/**
+ * Create arguments string to keep arity.
+ */
+
+function createArgumentsString (arity) {
+  var str = ''
+
+  for (var i = 0; i < arity; i++) {
+    str += ', arg' + i
+  }
+
+  return str.substr(2)
+}
+
 /**
  * Get the stack as array of call sites.
  */
@@ -415,20 +415,29 @@ function wrapfunction (fn, message) {
     throw new TypeError('argument fn must be a function')
   }
 
-  var args = createArgumentsString(fn.length)
+  var deprecate = this
   var stack = getStack()
   var site = callSiteLocation(stack[1])
 
   site.name = fn.name
 
-  // eslint-disable-next-line no-new-func
-  var deprecatedfn = new Function('fn', 'log', 'deprecate', 'message', 'site',
-    '"use strict"\n' +
-    'return function (' + args + ') {' +
-    'log.call(deprecate, message, site)\n' +
-    'return fn.apply(this, arguments)\n' +
-    '}')(fn, log, this, message, site)
-
+  var deprecatedfn = function () {
+    log.call(deprecate, message, site)
+    return fn.apply(this, arguments)
+  }
+  try {
+    Object.defineProperty(deprecatedfn, 'length', { value: fn.length })
+  } catch (e) {
+    // Fallback for NodeJS 2.5 and below
+    var args = createArgumentsString(fn.length)
+    // eslint-disable-next-line no-new-func
+    deprecatedfn = new Function('fn', 'log', 'deprecate', 'message', 'site',
+      '"use strict"\n' +
+      'return function (' + args + ') {' +
+      'log.call(deprecate, message, site)\n' +
+      'return fn.apply(this, arguments)\n' +
+      '}')(fn, log, this, message, site)
+  }
   return deprecatedfn
 }
 

test/fixtures/basic.js

@@ -0,0 +1,8 @@
+
+var deprecate = require('../..')('basic')
+
+var object = { foo: 'bar' }
+deprecate.property(object, 'foo')
+
+function fn () {}
+deprecate.function(fn)

test/test.js

@@ -10,6 +10,16 @@ var script = path.join(__dirname, 'fixtures', 'script.js')
 var spawn = require('child_process').spawn
 var strictlib = libs.strict
 
+function isNodeVersionGE (required) {
+  var nodeVersion = process.version.substr(1).split('.')
+  for (var i = 0; i < required.length; i++) {
+    if (+nodeVersion[i] < required[i]) {
+      return false
+    }
+  }
+  return true
+}
+
 describe('depd(namespace)', function () {
   it('creates deprecated function', function () {
     assert.strictEqual(typeof depd('test'), 'function')
@@ -730,9 +740,9 @@ describe('node script.js', function () {
 ;(function () {
   // --*-deprecation switches are 0.8+
   // no good way to feature detect this sync
-  var describe = /^v0\.6\./.test(process.version)
-    ? global.describe.skip
-    : global.describe
+  var describe = isNodeVersionGE([0, 8])
+    ? global.describe
+    : global.describe.skip
 
   describe('node --no-deprecation script.js', function () {
     it('should suppress deprecation message', function (done) {
@@ -755,6 +765,19 @@ describe('node script.js', function () {
   })
 }())
 
+describe('node --disallow-code-generation-from-strings script.js', function () {
+  it('should run without error', function (done) {
+    if (!isNodeVersionGE([9])) this.skip() // --disallow-code-generation-from-strings is 9+
+
+    var basic = path.join(__dirname, 'fixtures', 'basic.js')
+    captureChildStderr(basic, ['--disallow-code-generation-from-strings'], function (err, stderr) {
+      if (err) return done(err)
+      assert.strictEqual(stderr, '')
+      done()
+    })
+  })
+})
+
 function captureChildStderr (script, opts, callback) {
   var chunks = []
   var env = { PATH: process.env.PATH }