[Bug]: Parsing doesn't finish for unmatched bracket in TypeScript type expression

[woongsikchoi]

💻

• Would you like to work on a fix?

How are you using Babel?

@babel/cli

Input code

type Foo = ([;

Configuration file name

babel.config.json

Configuration

{
  "presets": ["@babel/preset-typescript"]
}

Current and expected behavior

Current behavior - parsing does not finish
Expected behavior - a syntax error should be thrown

Environment

System:
OS: Linux 4.4 Ubuntu 20.04.2 LTS (Focal Fossa)
Binaries:
Node: 16.13.1 - ~/local/lib/node-v16.13.1-linux-x64/bin/node
npm: 8.1.2 - ~/local/lib/node-v16.13.1-linux-x64/bin/npm
npmPackages:
@babel/cli: ^7.17.6 => 7.17.6
@babel/core: ^7.17.5 => 7.17.5
@babel/preset-typescript: ^7.16.7 => 7.16.7

Possible solution

The problem seems to occur at tsSkipParameterStart() in packages/babel-parser/src/plugins/typescript/index.js

      if (this.match(tt.bracketL)) {
        let braceStackCounter = 1;
        this.next();

        while (braceStackCounter > 0) {
          if (this.match(tt.bracketL)) {
            ++braceStackCounter;
          } else if (this.match(tt.bracketR)) {
            --braceStackCounter;
          }
          this.next();
        }
        return true;
      }

In the above while loop, a syntax error should be thrown when tt.eof is matched.
(or maybe just returning false would work?)

Additional context

No response

[babel-bot]

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