Add path mapping for app directory in package.json

[jonrohan]

What are you trying to accomplish?

PR #4096 introduced an exports map to package.json for the first time (to publish the new ./classnames subpath). Before that PR there was no exports field, so consumers could deep-import compiled component modules directly from the filesystem, e.g.:

import type {ActionMenuElement} from '@primer/view-components/app/components/primer/alpha/action_menu/action_menu_element'

Once the exports map was added, the only thing covering those deep paths is the catch-all "./*": "./*". Because that target is a plain string with no types condition, TypeScript (under moduleResolution: bundler/node16) maps the extensionless import to a literal path with no extension and can't locate the adjacent .d.ts. This broke type resolution for every @primer/view-components/app/... deep import across consumers (e.g. github-ui has ~27 such imports), surfacing as:

Cannot find module '@primer/view-components/app/components/primer/alpha/action_menu/action_menu_element' or its corresponding type declarations.

This PR restores type resolution for deep app/* imports by adding a conditional subpath that exposes the types, import, and default conditions, placed before the catch-all so it takes precedence:

"exports": {
  ".": {
    "types": "./app/components/primer/primer.d.ts",
    "import": "./app/components/primer/primer.js",
    "require": "./app/assets/javascripts/primer_view_components.js"
  },
  "./classnames": {
    "types": "./static/classnames.d.ts",
    "import": "./static/classnames.js",
    "require": "./static/classnames.cjs"
  },
  "./app/*": {
    "types": "./app/*.d.ts",
    "import": "./app/*.js",
    "default": "./app/*.js"
  },
  "./*": "./*"
}

Integration

No production runtime/behavior change — this only affects how the published package's subpaths resolve for type-checkers and bundlers. It restores the pre-#4096 ability for consumers to deep-import app/* modules with full type information. Consumers (e.g. github-ui) require no code changes once a version including this fix is published.

Risk Assessment

• Low risk the change is small, highly observable, and easily rolled back.

This is an additive exports subpath that only widens resolution back to pre-#4096 behavior. It is trivially reverted and verifiable via tsc --traceResolution.

What approach did you choose and why?

I chose to add an explicit ./app/* conditional subpath rather than change the catch-all "./*" because:

• The types condition is required for TypeScript to map an extensionless deep import to its .d.ts; a bare string target ("./*": "./*") cannot express conditions.
• Scoping the conditional pattern to ./app/* keeps the change narrow and intentional (the published files list only ships app/** JS/d.ts plus static/*), while leaving the catch-all in place for any other static asset paths.
• Ordering matters: the more specific ./app/* pattern is listed before ./* so it wins for app/... imports.

I verified the fix against the installed package with a resolution trace:

Matched 'exports' condition 'types'.
Using 'exports' subpath './app/*' with target './app/components/primer/alpha/action_menu/action_menu_element.d.ts'.
... was successfully resolved

Anything you want to highlight for special attention from reviewers?

• Please confirm the . subpath types/import/require targets match the canonical entry points (I mirrored main/module/types from the existing package.json).
• Worth double-checking whether any consumers rely on deep-importing non-app/ paths through "./*"; those remain covered by the unchanged catch-all.
• Consider whether this warrants a patch changeset framed as a regression fix for Add classnames.js Set export to the CSS build #4096.

Accessibility

Merge checklist

• Added/updated tests
• Added/updated documentation
• Added/updated previews (Lookbook)
• Tested in Chrome
• Tested in Firefox
• Tested in Safari
• Tested in Edge

[changeset-bot]

🦋 Changeset detected

Latest commit: 5bf2e1d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@primer/view-components	Patch

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Click here if you're a maintainer who wants to add another changeset to this PR

[Copilot]

Pull request overview

This PR updates the published npm package subpath exports to restore TypeScript type resolution for deep @primer/view-components/app/... imports after an exports map was introduced previously.

Changes:

• Add an ./app/* conditional exports pattern that provides types/import/default targets for deep app/** imports.
• Add a patch changeset to publish the fix.

Show a summary per file

File	Description
package.json	Adds an exports subpath for ./app/* intended to restore TypeScript resolution for deep app/** imports.
.changeset/sunny-trams-turn.md	Adds a patch changeset to release the package.json exports adjustment.

Copilot's findings

• Files reviewed: 2/2 changed files
• Comments generated: 1