Normalize reused string-literal property names to identifiers in declaration emit

[Copilot]

Fixes #2400

Analysis

In tsgo, when emitting a declaration for a type whose nested object type was reused from a source-position node (via the pseudo-checker / pseudoTypeToNode path), property names that the user wrote as string literals were preserved verbatim — even when their text was a valid identifier. Meanwhile, the same property name produced by the freshly-constructed typeToTypeNode path (which uses createPropertyNameNodeForIdentifierOrLiteral) would emit as a plain identifier.

This caused inconsistent output like:

export declare const platformSlice: {
    query: {              // rebuilt: identifier
        "search": string; // reused: kept as string literal
        "user": string;   // reused: kept as string literal
    };
};

Fix

reuseName in internal/checker/nodecopy.go (only used for property names by the pseudo type node builder) now normalizes a reused StringLiteral whose text is a valid identifier into an Identifier, matching the behavior of createPropertyNameNodeForIdentifierOrLiteral. The name "new" is intentionally excluded so that "new"(): void on a method signature isn't rewritten into a construct signature — mirroring the existing isMethodNamedNew guard.

The result is consistent output, aligned with the TypeScript reference baselines (two existing submodule baselines now match strada exactly, so their .diff files were removed).

Copilot Checklist

• Add compiler test reproducing inconsistent quoting of string-named properties
• Fix reuseName to normalize string-literal property names with identifier-valid text
• Guard the normalization against "new" to preserve method signatures
• Update / remove affected reference baselines and submoduleAccepted.txt
• npx hereby build
• npx hereby test
• npx hereby lint
• npx hereby format

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Normalizes declaration emit output so that reused string-literal property names that are valid identifiers are emitted as identifiers, eliminating inconsistent quoting between rebuilt vs reused nested object types.

Changes:

• Normalize reused StringLiteral property names to Identifier (except "new") in reuseName.
• Update/clean up submodule baselines to match upstream exactly (remove accepted .diff artifacts).
• Add a new compiler test case and baselines covering nested reused object type property-name consistency.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
internal/checker/nodecopy.go	Normalizes reused string-literal property names to identifiers during node reuse, with a special-case for "new".
testdata/tests/cases/compiler/declarationEmitStringNamedPropertyConsistency.ts	Adds regression test reproducing inconsistent quoting and asserting consistent identifier emit.
testdata/submoduleAccepted.txt	Removes now-unneeded accepted baseline diff entry.
testdata/baselines/reference/submoduleAccepted/compiler/escapedReservedCompilerNamedIdentifier.js.diff	Deletes accepted diff file now matching upstream.
testdata/baselines/reference/submodule/conformance/jsDeclarationsPackageJson(target=es2015).types.diff	Deletes accepted diff file now matching upstream.
testdata/baselines/reference/submodule/conformance/jsDeclarationsPackageJson(target=es2015).types	Updates baseline output to reflect normalized property-name emit.
testdata/baselines/reference/submodule/compiler/escapedReservedCompilerNamedIdentifier.js	Updates baseline output to reflect normalized property-name emit.
testdata/baselines/reference/compiler/declarationEmitStringNamedPropertyConsistency.*	Adds baselines for the new regression test.

[weswigham]

Wanna remove this comment, too?

[jakebailey]

@copilot address this specific comment

[Copilot]

Removed the now-orphaned comment in f798665.

[weswigham]

Honestly, if the user uses a string we should probably respect that (which may have some minor significant for stringy numeric names w.r.t keyof), but this matches strada so 🤷‍♂️