fix: disallow expression after binding identifier of (#11355)

packages/babel-parser/src/plugins/flow.js

@@ -3456,4 +3456,18 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       });
       return this.finishNode(node, "EnumDeclaration");
     }
+
+    updateContext(prevType: TokenType): void {
+      if (
+        this.match(tt.name) &&
+        this.state.value === "of" &&
+        prevType === tt.name &&
+        this.input.slice(this.state.lastTokStart, this.state.lastTokEnd) ===
+          "interface"
+      ) {
+        this.state.exprAllowed = false;
+      } else {
+        super.updateContext(prevType);
+      }
+    }
   };

packages/babel-parser/src/tokenizer/context.js

@@ -59,7 +59,10 @@ tt.name.updateContext = function(prevType) {
   let allowed = false;
   if (prevType !== tt.dot) {
     if (
-      (this.state.value === "of" && !this.state.exprAllowed) ||
+      (this.state.value === "of" &&
+        !this.state.exprAllowed &&
+        prevType !== tt._function &&
+        prevType !== tt._class) ||
       (this.state.value === "yield" && this.prodParam.hasYield)
     ) {
       allowed = true;