fix: Properly handle EnumValue in Flow#canOverflow (AssemblyScript#2032)

Author: romdotdog

src/flow.ts

@@ -26,9 +26,9 @@ import {
  Function,
  Element,
  ElementKind,
- Global,
  Field,
- Class
+ Class,
+ TypedElement
 } from "./program";
 
 import {
@@ -1218,8 +1218,8 @@ export class Flow {
  case ExpressionId.GlobalGet: {
  // TODO: this is inefficient because it has to read a string
  let global = assert(this.parentFunction.program.elementsByName.get(assert(getGlobalGetName(expr))));
- assert(global.kind == ElementKind.GLOBAL);
- return canConversionOverflow((<Global>global).type, type);
+ assert(global.kind == ElementKind.GLOBAL || global.kind == ElementKind.ENUMVALUE);
+ return canConversionOverflow((<TypedElement>global).type, type);
  }
 
  case ExpressionId.Binary: {

tests/compiler/enum-return-error.json

@@ -0,0 +1,8 @@
+{
+ "asc_flags": [
+ ],
+ "stderr": [
+ "AS200: Conversion from type 'i32' to 'bool' requires an explicit cast.",
+ "EOF"
+ ]
+}

tests/compiler/enum-return-error.ts

@@ -0,0 +1,11 @@
+enum Bar {
+ Baz
+}
+
+function foo(): boolean {
+ return Bar.Baz;
+}
+
+foo();
+
+ERROR("EOF");