Revert variadic back to a non-eval approach.

lib/variadic.js

@@ -4,40 +4,21 @@ function variadic(fn) {
   if (!isFn(fn)) throw new TypeError('Parameter `fn` must be a function.')
 
   const argc  = fn.length - 1
-      , argn  = String(fn).replace(argexp, "$1").split(/,\s*/).slice(0, -1)
-      , fnsrc = gensrc(fn, argn, argc)
 
-  return eval(fnsrc).bind(fn)
-}
-
-const argexp = /function[^\(]*\(([^\)]*)\)(?:\n|.)*/
-    , isFn   = require('./isFn')
-
-function gensrc(fn, argn, argc) {
   if (argc) {
-    body =
-      [ 'const head = [].slice.call(arguments, 0, '+argc+')'
-      , '    , tail = [].slice.call(arguments, '+argc+')'
-      , 'return this.apply(null, head.concat([tail]))'
-      ].join('\n')
+    return function variadic() {
+      const head = slice(arguments, 0, argc)
+          , tail = slice(arguments, argc)
+
+      return fn.apply(this, head.concat([tail]))
+    }
   } else {
-    body =
-      [ 'const rest = [].slice.call(arguments)'
-      , 'return this.call(null, rest)'
-      ].join('\n')
+    return function variadic() {
+      const rest = slice(arguments)
+      return fn.call(this, rest)
+    }
   }
+}
 
-  const src =
-        [ '(function() {'
-        , '  var {name} = function {name}({params}) {'
-        , '    ' + body.replace(/\n/g, '\n    ')
-        , '  }'
-        , '  return {name}'
-        , '}())'
-        ]
-        .join('\n')
-        .replace(/{name}/g, fn.name || 'variadic')
-        .replace(/{params}/g, argn.join(', '))
-
-  return src
-}
+const slice = require('./slice')
+    , isFn  = require('./isFn')

test/variadic.js

@@ -33,11 +33,6 @@ describe('variadic', function() {
       describe('when given `' + src(fn) + '`', function() {
         const varfn = variadic(fn)
 
-        it('should return a function of length ' + (fn.length - 1), function() {
-          expect(varfn).to.be.a('function')
-          expect(varfn.length).to.equal(fn.length - 1)
-        })
-
         each(test.slice(1), function(args) {
           const argsrc = args.length? '`' + src(args).slice(1, -1) + '`' : 'nothing'