Unused identifiers compiler code

[sarangan12]

Fixes #

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[mhegazy]

this should not be deleted.

[sarangan12]

Done

[mhegazy]

why not all signatures?

[sarangan12]

I have already tried this. But checkSignatureDeclaration is also called from CheckConstructorDeclartion and checkFunctionOrMethodDeclaration (before their body is processed). So, we should put them in the condition

[mhegazy]

thanks @sarangan12, and sorry for the delay. just a few more comments.

[sarangan12]

@mhegazy Changed the code per PR comments and also added the scenario for TypeParameters in interfaces. Kindly review

[mhegazy]

if (declaration.kind === SyntaxKind.ImportSpecifier || declaration.kind === SyntaxKind.ImportClause || declaration.kind === SyntaxKind.NamespaceImport || declaration.kind === SyntaxKind.ImportEqualsDeclaration) {
     error(declaration.name, Diagnostics._0_is_declared_but_never_used, localValue.name);
}

[mhegazy]

i am still not sure i understand why checkUnusedImports is not part of the checkUnusedModuleLocals?

[mhegazy]

👍

[ligaz]

Hey @sarangan12

I just tested this feature on my project and received 'Member' is declared but never used.

Here are my files:
a.ts

import { Member } from './b';

declare module './b' {
  interface Member {
  }
}

b.ts

export interface Member {
}

The code compiles just fine without specifying the compiler flags.

Is this expected?

[mhegazy]

You do not need the import, it contributes nothing to the module augmentation.

[ligaz]

If I remove the import I get Ambient module declaration cannot specify relative module name.

[mhegazy]

The file needs to be an external module. at least one import of export declarations. so you could either add an import without a name binding:

import "./b";

or add an empty export:

export {};

[ligaz]

I already tried to import it without a name which results in: '"./b"' is declared but never used.

[ligaz]

Also to be more precise I'm actually using the imported Member in the first file. So the code looks more like:
a.ts

import { Member } from './b';

declare module './b' {
  interface Member {
  }
}

const m: Member = ...;
export m;

[mhegazy]

that is a bug then. let me see why it is happening.

[mhegazy]

I have a fix out in #9434