ngtrue / node / unresolvableTypes

Function: unresolvableTypes()

unresolvableTypes(options): Promise<readonly string[]>

Defined in: src/node/unresolvable-types.ts:67

Every subpath whose TYPES do not resolve, under each mode, as one sentence each. An empty array is a pass.

it('resolves its types the way a consumer will', async () => {
  expect(await unresolvableTypes({ packageDir: 'dist' })).toEqual([]);
});

This runs TypeScript's own resolver — the same call tsc and the editor make — against a throwaway directory with the package symlinked into node_modules. Nothing about the resolution is reimplemented, which matters more here than anywhere else in ngtrue: the rules are intricate (condition ORDER decides the answer, types must precede import, a missing types silently falls through to the JavaScript), they differ per mode, and a hand-rolled approximation of them would agree with the real thing on every package that was already correct.

Probing through a symlinked node_modules rather than through TypeScript's self-reference support is deliberate too: a consumer resolves the package from node_modules, and that is the layout whose answer matters.

A subpath that resolves to JavaScript is reported as loudly as one that resolves to nothing. It is the worse of the two — a consumer gets any, no error, and the package appears to work until something that should not have compiled ships.

What it does not check

Wildcard subpaths are skipped, and the skip is reported so it cannot pass for a pass. Each one stands for an open set, and a single sample would say nothing about the rest of it.

Only the conditions this package actually declares are probed. An ESM-only package has no require branch, and reporting one missing would be reporting a design decision as a defect. If a package means to be dual, the check that it IS dual belongs in unresolvedExports, where the manifest is the subject.

typescript has to be installed. It is an optional peer dependency of ngtrue, and this is the only function that needs it. Any repository shipping a typed package has it already; one that somehow does not gets an error saying so rather than a pass.

Parameters

options

UnresolvableTypesOptions

Returns

Promise<readonly string[]>