Skip to content

fix: suppress TS4055/TS4073 for protected methods using typeof parameter #63221

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
umeshmore45 wants to merge 2 commits into from
+277 −1
Closed

fix: suppress TS4055/TS4073 for protected methods using typeof parameter #63221

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
6f43b64
fix(declaration-emit): suppress TS4055/TS4073 for protected methods u…
umeshmore45 Mar 8, 2026
c517acb
fix(checker): treat typeof parameter as accessible in declaration emit
umeshmore45 Mar 8, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions src/compiler/checker.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6158,6 +6158,11 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
errorNode: firstIdentifier,
};
}
// Parameters are always in scope within their enclosing function; `typeof paramName` in a
// return type annotation is valid regardless of method visibility (public, protected, private).
if (symbol.declarations && every(symbol.declarations, isParameter)) {
return { accessibility: SymbolAccessibility.Accessible };
}
// Verify if the symbol is accessible
return hasVisibleDeclarations(symbol, shouldComputeAliasToMakeVisible) || {
accessibility: SymbolAccessibility.NotAccessible,
Expand Down
2 changes: 1 addition & 1 deletion src/compiler/transformers/declarations/diagnostics.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -353,7 +353,7 @@ export function createGetSymbolAccessibilityDiagnosticForNode(node: DeclarationD
};
}

function getReturnTypeVisibilityError(symbolAccessibilityResult: SymbolAccessibilityResult): SymbolAccessibilityDiagnostic {
function getReturnTypeVisibilityError(symbolAccessibilityResult: SymbolAccessibilityResult): SymbolAccessibilityDiagnostic | undefined {
let diagnosticMessage: DiagnosticMessage;
switch (node.kind) {
case SyntaxKind.ConstructSignature:
Expand Down
34 changes: 34 additions & 0 deletions tests/baselines/reference/protectedMethodTypeofParameter.d.symbols
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,34 @@
//// [tests/cases/compiler/protectedMethodTypeofParameter.d.ts] ////

=== protectedMethodTypeofParameter.d.ts ===
export interface Properties {
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.d.ts, 0, 0))

propertyA: number;
>propertyA : Symbol(Properties.propertyA, Decl(protectedMethodTypeofParameter.d.ts, 0, 29))

propertyB: string;
>propertyB : Symbol(Properties.propertyB, Decl(protectedMethodTypeofParameter.d.ts, 1, 22))
}
export declare class A {
>A : Symbol(A, Decl(protectedMethodTypeofParameter.d.ts, 3, 1))

getPropertyValue_Ok(properties: Properties, propertyName: keyof Properties): Properties[typeof propertyName];
>getPropertyValue_Ok : Symbol(A.getPropertyValue_Ok, Decl(protectedMethodTypeofParameter.d.ts, 4, 24))
>properties : Symbol(properties, Decl(protectedMethodTypeofParameter.d.ts, 5, 24))
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.d.ts, 0, 0))
>propertyName : Symbol(propertyName, Decl(protectedMethodTypeofParameter.d.ts, 5, 47))
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.d.ts, 0, 0))
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.d.ts, 0, 0))
>propertyName : Symbol(propertyName, Decl(protectedMethodTypeofParameter.d.ts, 5, 47))

protected getPropertyValue_Error(properties: Properties, propertyName: keyof Properties): Properties[typeof propertyName];
>getPropertyValue_Error : Symbol(A.getPropertyValue_Error, Decl(protectedMethodTypeofParameter.d.ts, 5, 113))
>properties : Symbol(properties, Decl(protectedMethodTypeofParameter.d.ts, 6, 37))
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.d.ts, 0, 0))
>propertyName : Symbol(propertyName, Decl(protectedMethodTypeofParameter.d.ts, 6, 60))
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.d.ts, 0, 0))
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.d.ts, 0, 0))
>propertyName : Symbol(propertyName, Decl(protectedMethodTypeofParameter.d.ts, 6, 60))
}

37 changes: 37 additions & 0 deletions tests/baselines/reference/protectedMethodTypeofParameter.d.types
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,37 @@
//// [tests/cases/compiler/protectedMethodTypeofParameter.d.ts] ////

=== protectedMethodTypeofParameter.d.ts ===
export interface Properties {
propertyA: number;
>propertyA : number
> : ^^^^^^

propertyB: string;
>propertyB : string
> : ^^^^^^
}
export declare class A {
>A : A
> : ^

getPropertyValue_Ok(properties: Properties, propertyName: keyof Properties): Properties[typeof propertyName];
>getPropertyValue_Ok : (properties: Properties, propertyName: keyof Properties) => Properties[typeof propertyName]
> : ^ ^^ ^^ ^^ ^^^^^
>properties : Properties
> : ^^^^^^^^^^
>propertyName : keyof Properties
> : ^^^^^^^^^^^^^^^^
>propertyName : keyof Properties
> : ^^^^^^^^^^^^^^^^

protected getPropertyValue_Error(properties: Properties, propertyName: keyof Properties): Properties[typeof propertyName];
>getPropertyValue_Error : (properties: Properties, propertyName: keyof Properties) => Properties[typeof propertyName]
> : ^ ^^ ^^ ^^ ^^^^^
>properties : Properties
> : ^^^^^^^^^^
>propertyName : keyof Properties
> : ^^^^^^^^^^^^^^^^
>propertyName : keyof Properties
> : ^^^^^^^^^^^^^^^^
}

45 changes: 45 additions & 0 deletions tests/baselines/reference/protectedMethodTypeofParameter.js
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,45 @@
//// [tests/cases/compiler/protectedMethodTypeofParameter.ts] ////

//// [protectedMethodTypeofParameter.ts]
export interface Properties {
propertyA: number;
propertyB: string;
}

export class A {
public getPropertyValue_Ok(
properties: Properties,
propertyName: keyof Properties,
): Properties[typeof propertyName] {
return properties[propertyName];
}

protected getPropertyValue_Error(
properties: Properties,
propertyName: keyof Properties,
): Properties[typeof propertyName] {
return properties[propertyName];
}
}


//// [protectedMethodTypeofParameter.js]
export class A {
getPropertyValue_Ok(properties, propertyName) {
return properties[propertyName];
}
getPropertyValue_Error(properties, propertyName) {
return properties[propertyName];
}
}


//// [protectedMethodTypeofParameter.d.ts]
export interface Properties {
propertyA: number;
propertyB: string;
}
export declare class A {
getPropertyValue_Ok(properties: Properties, propertyName: keyof Properties): Properties[typeof propertyName];
protected getPropertyValue_Error(properties: Properties, propertyName: keyof Properties): Properties[typeof propertyName];
}
57 changes: 57 additions & 0 deletions tests/baselines/reference/protectedMethodTypeofParameter.symbols
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,57 @@
//// [tests/cases/compiler/protectedMethodTypeofParameter.ts] ////

=== protectedMethodTypeofParameter.ts ===
export interface Properties {
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.ts, 0, 0))

propertyA: number;
>propertyA : Symbol(Properties.propertyA, Decl(protectedMethodTypeofParameter.ts, 0, 29))

propertyB: string;
>propertyB : Symbol(Properties.propertyB, Decl(protectedMethodTypeofParameter.ts, 1, 20))
}

export class A {
>A : Symbol(A, Decl(protectedMethodTypeofParameter.ts, 3, 1))

public getPropertyValue_Ok(
>getPropertyValue_Ok : Symbol(A.getPropertyValue_Ok, Decl(protectedMethodTypeofParameter.ts, 5, 16))

properties: Properties,
>properties : Symbol(properties, Decl(protectedMethodTypeofParameter.ts, 6, 29))
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.ts, 0, 0))

propertyName: keyof Properties,
>propertyName : Symbol(propertyName, Decl(protectedMethodTypeofParameter.ts, 7, 27))
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.ts, 0, 0))

): Properties[typeof propertyName] {
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.ts, 0, 0))
>propertyName : Symbol(propertyName, Decl(protectedMethodTypeofParameter.ts, 7, 27))

return properties[propertyName];
>properties : Symbol(properties, Decl(protectedMethodTypeofParameter.ts, 6, 29))
>propertyName : Symbol(propertyName, Decl(protectedMethodTypeofParameter.ts, 7, 27))
}

protected getPropertyValue_Error(
>getPropertyValue_Error : Symbol(A.getPropertyValue_Error, Decl(protectedMethodTypeofParameter.ts, 11, 3))

properties: Properties,
>properties : Symbol(properties, Decl(protectedMethodTypeofParameter.ts, 13, 35))
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.ts, 0, 0))

propertyName: keyof Properties,
>propertyName : Symbol(propertyName, Decl(protectedMethodTypeofParameter.ts, 14, 27))
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.ts, 0, 0))

): Properties[typeof propertyName] {
>Properties : Symbol(Properties, Decl(protectedMethodTypeofParameter.ts, 0, 0))
>propertyName : Symbol(propertyName, Decl(protectedMethodTypeofParameter.ts, 14, 27))

return properties[propertyName];
>properties : Symbol(properties, Decl(protectedMethodTypeofParameter.ts, 13, 35))
>propertyName : Symbol(propertyName, Decl(protectedMethodTypeofParameter.ts, 14, 27))
}
}

68 changes: 68 additions & 0 deletions tests/baselines/reference/protectedMethodTypeofParameter.types
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,68 @@
//// [tests/cases/compiler/protectedMethodTypeofParameter.ts] ////

=== protectedMethodTypeofParameter.ts ===
export interface Properties {
propertyA: number;
>propertyA : number
> : ^^^^^^

propertyB: string;
>propertyB : string
> : ^^^^^^
}

export class A {
>A : A
> : ^

public getPropertyValue_Ok(
>getPropertyValue_Ok : (properties: Properties, propertyName: keyof Properties) => Properties[typeof propertyName]
> : ^ ^^ ^^ ^^ ^^^^^

properties: Properties,
>properties : Properties
> : ^^^^^^^^^^

propertyName: keyof Properties,
>propertyName : keyof Properties
> : ^^^^^^^^^^^^^^^^

): Properties[typeof propertyName] {
>propertyName : keyof Properties
> : ^^^^^^^^^^^^^^^^

return properties[propertyName];
>properties[propertyName] : string | number
> : ^^^^^^^^^^^^^^^
>properties : Properties
> : ^^^^^^^^^^
>propertyName : keyof Properties
> : ^^^^^^^^^^^^^^^^
}

protected getPropertyValue_Error(
>getPropertyValue_Error : (properties: Properties, propertyName: keyof Properties) => Properties[typeof propertyName]
> : ^ ^^ ^^ ^^ ^^^^^

properties: Properties,
>properties : Properties
> : ^^^^^^^^^^

propertyName: keyof Properties,
>propertyName : keyof Properties
> : ^^^^^^^^^^^^^^^^

): Properties[typeof propertyName] {
>propertyName : keyof Properties
> : ^^^^^^^^^^^^^^^^

return properties[propertyName];
>properties[propertyName] : string | number
> : ^^^^^^^^^^^^^^^
>properties : Properties
> : ^^^^^^^^^^
>propertyName : keyof Properties
> : ^^^^^^^^^^^^^^^^
}
}

8 changes: 8 additions & 0 deletions tests/cases/compiler/protectedMethodTypeofParameter.d.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,8 @@
export interface Properties {
propertyA: number;
propertyB: string;
}
export declare class A {
getPropertyValue_Ok(properties: Properties, propertyName: keyof Properties): Properties[typeof propertyName];
protected getPropertyValue_Error(properties: Properties, propertyName: keyof Properties): Properties[typeof propertyName];
}
22 changes: 22 additions & 0 deletions tests/cases/compiler/protectedMethodTypeofParameter.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,22 @@
// @declaration: true

export interface Properties {
propertyA: number;
propertyB: string;
}

export class A {
public getPropertyValue_Ok(
properties: Properties,
propertyName: keyof Properties,
): Properties[typeof propertyName] {
return properties[propertyName];
}

protected getPropertyValue_Error(
properties: Properties,
propertyName: keyof Properties,
): Properties[typeof propertyName] {
return properties[propertyName];
}
Comment on lines +8 to +21
Copy link

Copilot AI Mar 8, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The new test covers the protected-method return type case, but it doesn't cover the TS4073 scenario from the issue where another parameter’s type references typeof propertyName (e.g. propertyValue: Properties[typeof propertyName]). Adding that protected setter-style method (and asserting the .d.ts contains it without diagnostics) would prevent regressions and ensure the PR actually fixes both TS4055 and TS4073.

Copilot generated this review using guidance from repository custom instructions.
}
Loading