Fix regression in computed methods. [closes #807]

src/acorn/parser/class-fields.js

@@ -1,9 +1,10 @@
 // A loose implementation of class fields syntax.
 // https://github.com/tc39/proposal-class-fields
+// https://github.com/tc39/proposal-static-class-features
 
 import CHAR_CODE from "../../constant/char-code.js"
 
-import lookahead from "../../parse/lookahead.js"
+import branch from "../../parse/branch.js"
 import shared from "../../shared.js"
 import { tokTypes as tt } from "../../acorn.js"
 import wrap from "../../util/wrap.js"
@@ -42,41 +43,47 @@ function init() {
       return Reflect.apply(func, this, args)
     }
 
-    const next = lookahead(this)
-    const nextType = next.type
+    const branched1 = branch(this)
+    const dummyNode = this.startNode()
 
-    if (nextType === tt.parenL) {
+    branched1.parsePropertyName(dummyNode)
+
+    const branched1Type = branched1.type
+
+    if (branched1Type === tt.parenL) {
       return Reflect.apply(func, this, args)
     }
 
-    if (nextType !== tt.braceR &&
-        nextType !== tt.eq &&
-        nextType !== tt.semi) {
+    if (branched1Type !== tt.braceR &&
+        branched1Type !== tt.eq &&
+        branched1Type !== tt.semi) {
       if (this.isContextual("async") ||
           this.isContextual("get") ||
           this.isContextual("set")) {
         return Reflect.apply(func, this, args)
       }
 
       if (this.isContextual("static")) {
-        if (nextType === tt.star) {
+        if (branched1Type === tt.star) {
           return Reflect.apply(func, this, args)
         }
 
-        const nextNextType = lookahead(next).type
+        const branched2 = branch(branched1)
+
+        branched2.parsePropertyName(dummyNode)
 
-        if (nextNextType !== tt.braceR &&
-            nextNextType !== tt.eq &&
-            nextNextType !== tt.semi &&
-            (next.isContextual("async") ||
-             next.isContextual("get") ||
-             next.isContextual("set"))) {
+        const branched2Type = branched2.type
+
+        if (branched2Type === tt.parenL) {
           return Reflect.apply(func, this, args)
         }
 
-        next.parsePropertyName(this.startNode())
-
-        if (next.type === tt.parenL) {
+        if (branched2Type !== tt.braceR &&
+            branched2Type !== tt.eq &&
+            branched2Type !== tt.semi &&
+            (branched1.isContextual("async") ||
+             branched1.isContextual("get") ||
+             branched1.isContextual("set"))) {
           return Reflect.apply(func, this, args)
         }
       }
@@ -85,8 +92,8 @@ function init() {
     const node = this.startNode()
 
     node.static =
-      nextType !== tt.braceR &&
-      nextType !== tt.eq &&
+      branched1Type !== tt.braceR &&
+      branched1Type !== tt.eq &&
       this.eatContextual("static")
 
     this.parsePropertyName(node)

src/parse/branch.js

@@ -0,0 +1,51 @@
+import Parser from "../parser.js"
+
+import shared from "../shared.js"
+
+function init() {
+  let flyweight
+
+  function branch(parser) {
+    if (flyweight === void 0 ||
+        flyweight === parser) {
+      flyweight = createFlyweight()
+    }
+
+    flyweight.awaitIdentPos = parser.awaitIdentPos
+    flyweight.awaitPos = parser.awaitPos
+    flyweight.containsEsc = parser.containsEsc
+    flyweight.curLine = parser.curLine
+    flyweight.end = parser.end
+    flyweight.exprAllowed = parser.exprAllowed
+    flyweight.inModule = parser.inModule
+    flyweight.input = parser.input
+    flyweight.inTemplateElement = parser.inTemplateElement
+    flyweight.lastTokEnd = parser.lastTokEnd
+    flyweight.lastTokStart = parser.lastTokStart
+    flyweight.lineStart = parser.lineStart
+    flyweight.pos = parser.pos
+    flyweight.potentialArrowAt = parser.potentialArrowAt
+    flyweight.sourceFile = parser.sourceFile
+    flyweight.start = parser.start
+    flyweight.strict = parser.strict
+    flyweight.type = parser.type
+    flyweight.value = parser.value
+    flyweight.yieldPos = parser.yieldPos
+
+    return flyweight
+  }
+
+  function createFlyweight() {
+    return Parser.create("", {
+      allowAwaitOutsideFunction: true,
+      allowReturnOutsideFunction: true,
+      ecmaVersion: 10
+    })
+  }
+
+  return branch
+}
+
+export default shared.inited
+  ? shared.module.parseBranch
+  : shared.module.parseBranch = init()

src/parse/lookahead.js

@@ -1,48 +1,13 @@
-import Parser from "../parser.js"
-
+import branch from "./branch.js"
 import shared from "../shared.js"
 
 function init() {
-  let flyweight
-
   function lookahead(parser) {
-    if (flyweight === void 0 ||
-        flyweight === parser) {
-      flyweight = createFlyweight()
-    }
-
-    flyweight.awaitIdentPos = parser.awaitIdentPos
-    flyweight.awaitPos = parser.awaitPos
-    flyweight.containsEsc = parser.containsEsc
-    flyweight.curLine = parser.curLine
-    flyweight.end = parser.end
-    flyweight.exprAllowed = parser.exprAllowed
-    flyweight.inModule = parser.inModule
-    flyweight.input = parser.input
-    flyweight.inTemplateElement = parser.inTemplateElement
-    flyweight.lastTokEnd = parser.lastTokEnd
-    flyweight.lastTokStart = parser.lastTokStart
-    flyweight.lineStart = parser.lineStart
-    flyweight.pos = parser.pos
-    flyweight.potentialArrowAt = parser.potentialArrowAt
-    flyweight.sourceFile = parser.sourceFile
-    flyweight.start = parser.start
-    flyweight.strict = parser.strict
-    flyweight.type = parser.type
-    flyweight.value = parser.value
-    flyweight.yieldPos = parser.yieldPos
+    const branched = branch(parser)
 
-    flyweight.next()
-
-    return flyweight
-  }
+    branched.next()
 
-  function createFlyweight() {
-    return Parser.create("", {
-      allowAwaitOutsideFunction: true,
-      allowReturnOutsideFunction: true,
-      ecmaVersion: 10
-    })
+    return branched
   }
 
   return lookahead

test/compiler-tests.mjs

@@ -414,6 +414,7 @@ describe("compiler tests", () => {
       "  static async g() {}",
       "  static *h() {}",
       "  static async *i() {}",
+      "  [Symbol.iterator]() {}",
       "  async = 1;",
       "  get = 1",
       "  set = 1",