Fix scope-related regressions and await vs. class property initializers issue

Author: adams85

acorn/src/state.js

@@ -104,13 +104,14 @@ export class Parser {
   get inAsync() { return (this.currentVarScope().flags & SCOPE_ASYNC) > 0 && !this.currentVarScope().inClassFieldInit }
 
   get canAwait() {
-    if (this.currentThisScope().inClassFieldInit) return false
-    for (let i = this.scopeStack.length - 1; i >= 0; i--) {
-      let scope = this.scopeStack[i]
-      if (scope.flags & SCOPE_CLASS_STATIC_BLOCK) return false
-      if (scope.flags & SCOPE_FUNCTION) return (scope.flags & SCOPE_ASYNC) > 0
+    const scope = this.currentVarScope()
+    if (scope.flags & SCOPE_FUNCTION) {
+      return (scope.flags & SCOPE_ASYNC) && !scope.inClassFieldInit
     }
-    return (this.inModule && this.options.ecmaVersion >= 13) || this.options.allowAwaitOutsideFunction
+    if (scope.flags & SCOPE_TOP) {
+      return ((this.inModule && this.options.ecmaVersion >= 13) || this.options.allowAwaitOutsideFunction) && !scope.inClassFieldInit
+    }
+    return false
   }
 
   get allowSuper() {

acorn/src/statement.js

@@ -742,11 +742,13 @@ pp.parseClassField = function(field) {
 
   if (this.eat(tt.eq)) {
     // To raise SyntaxError if 'arguments' exists in the initializer.
-    const scope = this.currentThisScope()
-    const inClassFieldInit = scope.inClassFieldInit
-    scope.inClassFieldInit = true
+    const thisScope = this.currentThisScope(), varScope = this.currentVarScope()
+    const thisScopeInClassFieldInit = thisScope.inClassFieldInit
+    const varScopeInClassFieldInit = varScope.inClassFieldInit
+    thisScope.inClassFieldInit = varScope.inClassFieldInit = true
     field.value = this.parseMaybeAssign()
-    scope.inClassFieldInit = inClassFieldInit
+    thisScope.inClassFieldInit = thisScopeInClassFieldInit
+    varScope.inClassFieldInit = varScopeInClassFieldInit
   } else {
     field.value = null
   }