no-duplicate-imports: Allow duplicate imports from separate ambient module declarations

[ghost]

PR checklist

• Addresses an existing issue: Multiple module declarations with similar imports cause "no-duplicate-imports" microsoft/dtslint#79
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

Overview of change:

Allows two ambient modules to have separate imports:

declare module "a" {
    import foo from "foo";
}
declare module "b" {
    import foo from "foo";
}

Preserves existing behavior for module augmentations.

@ajafff It would be nice to reuse more code from findImports in tsutils but it doesn't seem possible given that it currently takes the whole source file as input, so I can't run it on a single declare module.

CHANGELOG.md entry:

[bugfix] no-duplicate-imports: Allow duplicate imports from separate ambient module declarations

[ajafff]

LGTM with a suggestion

[ajafff]

you could add an additional check here if statement.name.kind === ts.SyntaxKind.StringLiteral, because namespaces cannot contain import statements.
and then you probably don't need the isModuleBlock check.

[ajafff]

It didn't check ImportEqualsDeclaration before your change. That's not a problem, but should be mentioned in the changelog.

[ghost]

It was right before because you might want named imports from a module in addition to importing it as a function. Removed this part.

[ajafff]

thanks @andy-ms

[mxl]

@ajafff Could you make a release with these changes?

[ajafff]

@mxl I could prepare a release PR, but I cannot do the actual release.
In addition there are other PRs that should be included in the next release. Seems like we just need to wait 😕