[api-extractor] Improve SymbolAnalyzer to support "export * from"

[octogonz]

The SymbolAnalyzer currently relies on TypeScriptHelpers.getImmediateAliasedSymbol() for determining whether a symbol was imported from an external package, and if so what module path was used to import it.

This approach cannot handle export * from '____' constructs, because there is no symbol alias that can be used to discover the export line. In API Extractor 6 this problem mostly affects the .d.ts rollups. For the API report, it simply includes extra definitions that technically belong to an external package.

For API Extractor 7 this problem is more serious, because everything uses the .d.ts rollups engine.

I have a plan to improve the SymbolAnalyzer, but it needs to wait until the initial AE7 branch is merged.

[octogonz]

When the .d.ts rollups encounter this issue, it sometimes produces this error:

"Program Bug: The symbol ____ is being imported after it was already registered as non-imported"

The reason is that it incorrectly believes the symbol is part of the current project, and then later discovers the inconsistency.

[octogonz]

I encountered this imported after it was already registered as non-imported error for a definition like this:

src/index.ts

export { SomeApi } from 'another-package';

The error only occurs if SomeApi was reachable by some other type alias. Otherwise it simply gets treated as a local reference. We should include this test case when validating the fix.

[nvh]

I encountered this error importing the EditorState from draft-js and using it in a class
A minimal reproduction looks like this:

import { EditorState } from "draft-js"
export class Text {
    editorState: EditorState
}

making the editorState private fixes the problem.
Example project:
registerd-as-non-imported.zip
Reproduction steps:

[octogonz]

Thanks for reporting this! I'll make sure we test your case as part of this fix.

[octogonz]

I encountered this error importing the EditorState from draft-js and using it in a class
A minimal reproduction looks like this:

import { EditorState } from "draft-js"
export class Text {
    editorState: EditorState
}

This is actually an instance of the other issue #663 which involves the export { x } construct.

Update: On further investigation this turned out to be an unrelated problem. I have opened Issue #1001 to track it

[octogonz]

Support for the export * from '____' construct is implemented in my upcoming PR #1002