fix: suppress TS4055/TS4073 for protected methods using typeof parameter

[umeshmore45]

Fixes #61591

Problem

Using typeof parameterName in the return type of a protected method incorrectly triggered TS4055. The same pattern on a public method worked fine.

export class A {
  protected getPropertyValue(
    properties: Properties,
    propertyName: keyof Properties,
  ): Properties[typeof propertyName] { // TS4055: private name 'propertyName'
    return properties[propertyName];
  }
}

Root Cause

During declaration emit, isEntityNameVisible resolves the symbol for typeof propertyName and calls hasVisibleDeclarations. Parameters are not part of any module export scope, so isDeclarationVisible returns false for them, causing a NotAccessible result and triggering TS4055.

Fix

Added an early return in isEntityNameVisible for parameter symbols, mirroring the existing short-circuit for SymbolFlags.TypeParameter. Parameters are always accessible within their function's scope — visibility modifiers on the method don't change that.

if (symbol.declarations && every(symbol.declarations, isParameter)) {
    return { accessibility: SymbolAccessibility.Accessible };
}

Checklist

• Associated issue in the Backlog milestone
• Code is up-to-date with main
• hereby runtests passes locally (46,182 conformance tests)
• New test case: tests/cases/compiler/protectedMethodTypeofParameter.ts

[Copilot]

Pull request overview

Fixes an incorrect TS4055/TS4073 accessibility diagnostic during declaration emit when a protected method signature uses a typeof parameterName type query.

Changes:

• Updates isEntityNameVisible to treat parameter symbols as always accessible within their containing signature during declaration emit.
• Adds a new compiler test case for protected method return types using typeof on a parameter.
• Adds new baseline outputs for the new test.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/compiler/checker.ts	Short-circuits symbol visibility for parameter symbols to prevent TS4055/TS4073 in declaration emit for typeof paramName.
tests/cases/compiler/protectedMethodTypeofParameter.ts	New regression test covering protected method return type with Properties[typeof propertyName].
tests/cases/compiler/protectedMethodTypeofParameter.d.ts	Adds a .d.ts alongside the test case (looks like emitted output); flagged in review as likely unintended.
tests/baselines/reference/protectedMethodTypeofParameter.js	Baselines the emit output (JS + .d.ts section) for the new test.
tests/baselines/reference/protectedMethodTypeofParameter.types	Baselines type information for the .ts input.
tests/baselines/reference/protectedMethodTypeofParameter.symbols	Baselines symbol information for the .ts input.
tests/baselines/reference/protectedMethodTypeofParameter.d.types	Baselines type information for the emitted .d.ts.
tests/baselines/reference/protectedMethodTypeofParameter.d.symbols	Baselines symbol information for the emitted .d.ts.

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[Copilot]

Pull request overview

Copilot reviewed 8 out of 9 changed files in this pull request and generated 1 comment.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 8 changed files in this pull request and generated no new comments.

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