Fix missing TS2725 error for class named 'Object' in non-ES2015 modules

[Copilot]

In CommonJS (and other non-ES2015 module formats), declaring class Object {} should produce error TS2725 because the emitted code for object spread depends on the global Object. The Go implementation was missing the checkClassNameCollisionWithObject call in checkCollisionsForDeclarationName.

// @module: commonjs
class Object {}
export let x = { ...{} }; // error TS2725: Class name cannot be 'Object' when targeting ES5 and above with module CommonJS.

Changes

• internal/checker/checker.go: Added checkClassNameCollisionWithObject — reports TS2725 when a non-ambient class is named "Object" and the file's emit module format is below ES2015. Wired it into checkCollisionsForDeclarationName for non-ambient class-like nodes, matching TypeScript's behavior.

• Test baselines: Removed .diff files and updated/added .errors.txt baselines for all affected tests whose Go output now matches the TypeScript reference:

  • exportClassNameWithObjectCommonJS, exportDefaultClassNameWithObject, checkForObjectTooStrict, instanceofOperator
  • nodeModulesGeneratedNameCollisions and nodeModulesAllowJsGeneratedNameCollisions (node16/18/20/nodenext variants) — correctly emits the error only for CJS-format files, not ESM-format files in the same project

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[jakebailey]

Why not fix #2087 and fix all of these?

[Copilot]

Pull request overview

This PR aligns the Go checker’s name-collision diagnostics with TypeScript by ensuring TS2725 is reported when a non-ambient class is named Object in files that emit to a non-ES2015 module format (e.g. CommonJS), and updates baseline outputs accordingly.

Changes:

• Added checkClassNameCollisionWithObject and invoked it from checkCollisionsForDeclarationName for non-ambient class-like nodes.
• Updated reference .errors.txt baselines to include TS2725 where Go output now matches the TypeScript reference.
• Removed now-unnecessary .errors.txt.diff files for the affected baseline tests.

Reviewed changes

Copilot reviewed 25 out of 25 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
internal/checker/checker.go	Adds TS2725 reporting for class Object under non-ES2015 emit module formats and wires it into collision checks.
testdata/baselines/reference/submodule/conformance/nodeModulesGeneratedNameCollisions(module=nodenext).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/conformance/nodeModulesGeneratedNameCollisions(module=nodenext).errors.txt	Updates expected diagnostics to include TS2725 for the CJS-format file.
testdata/baselines/reference/submodule/conformance/nodeModulesGeneratedNameCollisions(module=node20).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/conformance/nodeModulesGeneratedNameCollisions(module=node20).errors.txt	Updates expected diagnostics to include TS2725 for the CJS-format file.
testdata/baselines/reference/submodule/conformance/nodeModulesGeneratedNameCollisions(module=node18).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/conformance/nodeModulesGeneratedNameCollisions(module=node18).errors.txt	Updates expected diagnostics to include TS2725 for the CJS-format file.
testdata/baselines/reference/submodule/conformance/nodeModulesGeneratedNameCollisions(module=node16).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/conformance/nodeModulesGeneratedNameCollisions(module=node16).errors.txt	Updates expected diagnostics to include TS2725 for the CJS-format file.
testdata/baselines/reference/submodule/conformance/nodeModulesAllowJsGeneratedNameCollisions(module=nodenext).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/conformance/nodeModulesAllowJsGeneratedNameCollisions(module=nodenext).errors.txt	Updates expected diagnostics to include TS2725 for the CJS-format file (allowJs).
testdata/baselines/reference/submodule/conformance/nodeModulesAllowJsGeneratedNameCollisions(module=node20).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/conformance/nodeModulesAllowJsGeneratedNameCollisions(module=node20).errors.txt	Updates expected diagnostics to include TS2725 for the CJS-format file (allowJs).
testdata/baselines/reference/submodule/conformance/nodeModulesAllowJsGeneratedNameCollisions(module=node18).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/conformance/nodeModulesAllowJsGeneratedNameCollisions(module=node18).errors.txt	Updates expected diagnostics to include TS2725 for the CJS-format file (allowJs).
testdata/baselines/reference/submodule/conformance/nodeModulesAllowJsGeneratedNameCollisions(module=node16).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/conformance/nodeModulesAllowJsGeneratedNameCollisions(module=node16).errors.txt	Updates expected diagnostics to include TS2725 for the CJS-format file (allowJs).
testdata/baselines/reference/submodule/conformance/exportDefaultClassNameWithObject(target=es2015).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/conformance/exportDefaultClassNameWithObject(target=es2015).errors.txt	Adds/updates expected TS2725 output for default-exported class named Object under CommonJS.
testdata/baselines/reference/submodule/conformance/exportClassNameWithObjectCommonJS(target=es2015).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/conformance/exportClassNameWithObjectCommonJS(target=es2015).errors.txt	Adds/updates expected TS2725 output for exported class named Object under CommonJS.
testdata/baselines/reference/submodule/compiler/instanceofOperator(target=es2015).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/compiler/instanceofOperator(target=es2015).errors.txt	Updates expected diagnostics to include TS2725 in this scenario.
testdata/baselines/reference/submodule/compiler/checkForObjectTooStrict(target=es2015).errors.txt.diff	Removes obsolete baseline diff after outputs converged.
testdata/baselines/reference/submodule/compiler/checkForObjectTooStrict(target=es2015).errors.txt	Updates expected diagnostics to include TS2725 in this scenario.

[Copilot]

checkClassNameCollisionWithObject currently reports TS2725 solely based on the file’s emit module format. The diagnostic text is specific to “targeting ES5 and above”, but this helper doesn’t check the compilation target (c.languageVersion). Consider gating the error on c.languageVersion >= core.ScriptTargetES5 (or the equivalent target threshold used by the emitter) so we don’t report TS2725 for ES3 targets while still emitting an ES5+ specific message.