TS didnot transform `foo.return` from dot notation to bracket notation when targeting "ES5"

[AnnAngela]

Bug Report

🔎 Search Terms

I searched es5 dot notation but no relative issue.

🕗 Version & Regression Information

• This is a crash
• This changed between versions ______ and _______
• This is the behavior in every version I tried, and I reviewed the FAQ for entries about notation
• I was unable to test this on prior versions because _______

After ts 5.0, the target: ES3 configuration has been deprecated, but when I tried to configured the target as ES5, I noticed that the foo.return syntax was not transformed to bracket notation as required by the ECMAScript 5.1 Specification.

According to Section 11.2.1, the dot notation should use IdentifierName. However, Section 7.6 forbids using ReservedWord as IdentifierName. Furthermore, Section 7.6.1.1 lists the return as a Keywords which is a type of ReservedWord in Section 7.6.1.

⏯ Playground Link

Playground link with relevant code

💻 Code

const foo = {
    return: "foo",
};
console.info(foo.return);

🙁 Actual behavior

Output: console.info(foo.return);

🙂 Expected behavior

Output: console.info(foo["return"]);

[fatcerberus]

The spec text actually says:

An Identifier is an IdentifierName that is not a ReservedWord

But dotted property access uses IdentifierName, not Identifier. They are separate productions.

[AnnAngela]

Sorry for that ...