Recover from "missing semicolon" errors (#12437)

* Recover from "missing semicolon" errors

* Update other tests

* Fix flow

* Fix windows test

* Add back deleted test

packages/babel-parser/src/parser/error-message.js

@@ -99,6 +99,7 @@ export const ErrorMessages = Object.freeze({
   MissingClassName: "A class name is required",
   MissingEqInAssignment:
     "Only '=' operator can be used for specifying default value.",
+  MissingSemicolon: "Missing semicolon",
   MissingUnicodeEscape: "Expecting Unicode escape sequence \\uXXXX",
   MixingCoalesceWithLogical:
     "Nullish coalescing operator(??) requires parens when mixing with logical operators",

packages/babel-parser/src/parser/statement.js

@@ -915,9 +915,9 @@ export default class StatementParser extends ExpressionParser {
     init: ?(N.VariableDeclaration | N.Expression),
   ): N.ForStatement {
     node.init = init;
-    this.expect(tt.semi);
+    this.semicolon(/* allowAsi */ false);
     node.test = this.match(tt.semi) ? null : this.parseExpression();
-    this.expect(tt.semi);
+    this.semicolon(/* allowAsi */ false);
     node.update = this.match(tt.parenR) ? null : this.parseExpression();
     this.expect(tt.parenR);
 

packages/babel-parser/src/parser/util.js

@@ -105,8 +105,9 @@ export default class UtilParser extends Tokenizer {
   // Consume a semicolon, or, failing that, see if we are allowed to
   // pretend that there is a semicolon at this position.
 
-  semicolon(): void {
-    if (!this.isLineTerminator()) this.unexpected(null, tt.semi);
+  semicolon(allowAsi: boolean = true): void {
+    if (allowAsi ? this.isLineTerminator() : this.eat(tt.semi)) return;
+    this.raise(this.state.lastTokEnd, Errors.MissingSemicolon);
   }
 
   // Expect a token of a given type. If found, consume it, otherwise,