Syntax Error for `let` var declaration under semicolon-less instantiation expressions

[sosukesuzuki]

Bug Report

🔎 Search Terms

• instantiation expression semicolon

🕗 Version & Regression Information

• This is a bug of new syntax that is landed in TS 4.7

⏯ Playground Link

Playground link with relevant code

💻 Code

const foo = func<string>

let bar;

🙁 Actual behavior

Syntax error Cannot find name 'let'.(2304)

🙂 Expected behavior

Parsing successfully

[ahejlsberg]

Hmm, yeah, it seems were not doing the right thing when an instantiation expression is immediately followed by a strict mode reserved word (which includes interface and let). In non-strict mode interface and let are valid identifiers, but when they follow a type argument list and are immediately preceded by a line break, it is very unlikely that's the desired interpretation.