remove eslint 2 logic (babel/babel-eslint#361)

* remove old code

* remove async/await logic before eslint supported it

* not needed

eslint/babel-eslint-parser/babylon-to-espree/toAST.js

@@ -202,11 +202,6 @@ var astTransformVisitor = {
       }
     }
 
-    // async function as generator
-    if (path.isFunction()) {
-      if (node.async) node.generator = true;
-    }
-
     // TODO: remove (old esprima)
     if (path.isFunction()) {
       if (!node.defaults) {
@@ -214,13 +209,6 @@ var astTransformVisitor = {
       }
     }
 
-    // await transform to yield
-    if (path.isAwaitExpression()) {
-      node.type = "YieldExpression";
-      node.delegate = node.all;
-      delete node.all;
-    }
-
     // template string range fixes
     if (path.isTemplateLiteral()) {
       node.quasis.forEach(function (q) {

eslint/babel-eslint-parser/index.js

@@ -7,7 +7,6 @@ var t              = require("babel-types");
 var tt              = require("babylon").tokTypes;
 var traverse        = require("babel-traverse").default;
 
-var estraverse;
 var hasPatched = false;
 var eslintOptions = {};
 
@@ -37,39 +36,12 @@ function monkeypatch() {
 
   // get modules relative to what eslint will load
   var eslintMod = createModule(eslintLoc);
-  var escopeLoc = Module._resolveFilename("escope", eslintMod);
-  var escopeMod = createModule(escopeLoc);
-
-  // npm 3: monkeypatch estraverse if it's in escope
-  var estraverseRelative = escopeMod;
-  try {
-    var esrecurseLoc = Module._resolveFilename("esrecurse", eslintMod);
-    estraverseRelative = createModule(esrecurseLoc);
-  } catch (err) {}
-
   // contains all the instances of estraverse so we can modify them if necessary
   var estraverses = [];
-
-  // monkeypatch estraverse
-  estraverse = estraverseRelative.require("estraverse");
-  estraverses.push(estraverse);
-  Object.assign(estraverse.VisitorKeys, t.VISITOR_KEYS);
-
-  // monkeypatch estraverse-fb (only for eslint < 2.3.0)
-  try {
-    var estraverseFb = eslintMod.require("estraverse-fb");
-    estraverses.push(estraverseFb);
-    Object.assign(estraverseFb.VisitorKeys, t.VISITOR_KEYS);
-  } catch (err) {
-      // Ignore: ESLint v2.3.0 does not have estraverse-fb
-  }
-
   // ESLint v1.9.0 uses estraverse directly to work around https://github.com/npm/npm/issues/9663
   var estraverseOfEslint = eslintMod.require("estraverse");
-  if (estraverseOfEslint !== estraverseFb) {
   estraverses.push(estraverseOfEslint);
   Object.assign(estraverseOfEslint.VisitorKeys, t.VISITOR_KEYS);
-  }
 
   estraverses.forEach(function (estraverse) {
     estraverse.VisitorKeys.MethodDefinition.push("decorators");
@@ -77,6 +49,8 @@ function monkeypatch() {
   });
 
   // monkeypatch escope
+  var escopeLoc = Module._resolveFilename("escope", eslintMod);
+  var escopeMod = createModule(escopeLoc);
   var escope  = require(escopeLoc);
   var analyze = escope.analyze;
   escope.analyze = function (ast, opts) {

eslint/babel-eslint-parser/test/babel-eslint.js

@@ -56,7 +56,7 @@ function parseAndAssertSame(code) {
     range: true,
     comment: true,
     attachComment: true,
-    ecmaVersion: 6,
+    ecmaVersion: 8,
     sourceType: "module"
   });
   var babylonAST = babelEslint.parse(code);
@@ -455,5 +455,13 @@ describe("babylon-to-esprima", function () {
       parseAndAssertSame("var a = [ a, ...b ]");
       parseAndAssertSame("var a = sum(...b)");
     });
+
+    it("Async/Await", function() {
+      parseAndAssertSame(
+        `async function a() {
+          await 1;
+        }`
+      );
+    });
   });
 });

eslint/babel-eslint-parser/test/non-regression.js

@@ -11,7 +11,7 @@ function verifyAndAssertMessages(code, rules, expectedMessages, sourceType, over
       es6: true
     },
     parserOptions: {
-      ecmaVersion: 6,
+      ecmaVersion: 8,
       ecmaFeatures: {
         jsx: true,
         experimentalObjectRestSpread: true,