Maintenance: Replace resolve and resolve.exports with oxc-resolver

[valentinpalkovic]

Closes #

What I did

Stacked on top of #34625 (which introduces oxc-resolver and oxc-parser as runtime deps of code/core).

Now that oxc-resolver is available, the two remaining call sites of the legacy resolve and resolve.exports npm packages in code/core can be migrated. This PR removes both packages.

Why now

The change-detection PR (#34625) added oxc-resolver to code/core's runtime deps for its dependency-graph builder, but did not migrate the two pre-existing call sites that were still on the older resolvers. This PR closes that loop and lets us drop two transitive deps.

Checklist for Contributors

Testing

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

The existing GitDiffProvider.test.ts continues to pass (13/13). No new tests are added because the assertion would be "execa was called with a specific env" which over-specifies an implementation detail; the user-visible behavior is "concurrent commits no longer fail," which is verified manually.

Manual testing

1. cd code && yarn storybook:ui (or run any sandbox dev server in a repo).
2. In another terminal, repeatedly run touch code/core/src/foo.ts && git add code/core/src/foo.ts && git commit -m wip while the dev server is running.
3. Before this fix: occasionally fails with fatal: Unable to create '.git/index.lock': File exists.
4. After this fix: commits always succeed regardless of dev server activity.

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli-storybook/src/sandbox-templates.ts

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook publish.yml --field pr=<PR_NUMBER>

Summary by CodeRabbit

• Refactor
  • Switched to a new resolver that prefers ESM/browser entrypoints and uses a browser-first resolution order, with improved retry/fallback remapping for various JS/TS file extensions to reduce import resolution failures.
• Chores
  • Removed unused development dependencies from the workspace setup.

[coderabbitai]

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📝 Walkthrough

Walkthrough

Replaced resolve/resolve.exports with oxc-resolver and updated resolution logic in two modules to use resolver factories (ESM-preferring mainFields and browser-first conditions), preserved JS→TS/JSX→TSX fallback remapping, and added a require.resolve fallback for external modules.

Changes

Dependency & Resolver Migration to oxc-resolver

Layer / File(s)	Summary
Dependency Removal code/core/package.json	Removed resolve and resolve.exports from devDependencies.
Resolver Factory / Config code/core/src/common/utils/interpret-files.ts, code/core/src/mocking-utils/resolve.ts	Imported ResolverFactory from oxc-resolver and created resolver instances with extensions: [...] and mainFields: ['module','main']; mocking-utils/resolve.ts uses browser-first conditionNames and aliasFields for legacy browser.
API Surface code/core/src/common/utils/interpret-files.ts	Added export interface ResolveImportOptions { basedir: string }; changed resolveImport to accept ResolveImportOptions and introduced an internal resolveSync helper that throws a descriptive error on failure.
Core Resolution Logic code/core/src/common/utils/interpret-files.ts	Replaced prior resolve usage with oxc-resolver factory; removed packageFilter approach and kept the fallback that remaps .js/.mjs/.cjs → .ts and .jsx → .tsx before retrying resolution.
External Module Resolution code/core/src/mocking-utils/resolve.ts	Rewrote resolveExternalModule to use externalResolver.sync(root, path) and return result.path or fall back to require.resolve(..., { paths: [root] }); removed manual package.json/resolve.exports flow.
Tests / Documentation (none changed)	No tests or docs updated in this PR.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• storybookjs/storybook#32905: Modifies the same interpret-files.ts resolver logic and signature, overlapping with this migration.

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@code/core/src/common/utils/interpret-files.ts`:
- Around line 30-33: The ResolverFactory instantiated as importResolver lacks
conditionNames so packages using conditional exports won't resolve; update the
ResolverFactory call that creates importResolver (the ResolverFactory
instantiation near supportedExtensions/mainFields) to include conditionNames set
for server-side ESM (e.g., ['node','import']) so ESM conditional exports are
honored when resolving imports.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: dabe5719-4118-433f-a4a6-b6a25956f9fc

📥 Commits

Reviewing files that changed from the base of the PR and between 4a248d8 and 72e6893.

⛔ Files ignored due to path filters (1)

• yarn.lock is excluded by !**/yarn.lock, !**/*.lock

📒 Files selected for processing (3)

• code/core/package.json
• code/core/src/common/utils/interpret-files.ts
• code/core/src/mocking-utils/resolve.ts

💤 Files with no reviewable changes (1)

• code/core/package.json

[storybook-app-bot]

Package Benchmarks

^{Commit: 553f2d1, ran on 20 May 2026 at 12:15:33 UTC}

The following packages have significant changes to their size or dependencies:

storybook

	Before	After	Difference
Dependency count	72	72	0
Self size	20.30 MB	20.25 MB	🎉 -53 KB 🎉
Dependency size	36.17 MB	36.17 MB	0 B
Bundle Size Analyzer	Link	Link

@storybook/cli

	Before	After	Difference
Dependency count	203	203	0
Self size	908 KB	908 KB	0 B
Dependency size	87.59 MB	87.54 MB	🎉 -53 KB 🎉
Bundle Size Analyzer	Link	Link

@storybook/codemod

	Before	After	Difference
Dependency count	196	196	0
Self size	32 KB	32 KB	0 B
Dependency size	86.08 MB	86.03 MB	🎉 -53 KB 🎉
Bundle Size Analyzer	Link	Link

create-storybook

	Before	After	Difference
Dependency count	73	73	0
Self size	1.08 MB	1.08 MB	0 B
Dependency size	56.48 MB	56.43 MB	🎉 -53 KB 🎉
Bundle Size Analyzer	node	node

[coderabbitai]

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

code/core/src/common/utils/interpret-files.ts (1)

39-59: ⚠️ Potential issue | 🟠 Major | ⚡ Quick win

Try all matching TypeScript source extensions in the fallback path.

This retry only remaps to one target (.ts, or .tsx for .jsx), so valid files like foo.tsx, foo.mts, or foo.cts still fail even though they are listed in supportedExtensions. That turns legitimate ESM-style imports into false negatives.

Suggested fix

 export function resolveImport(id: string, options: ResolveImportOptions): string {
   try {
     return resolveSync(id, options.basedir);
   } catch (error) {
     const ext = extname(id);
@@
-    const newId = ['.js', '.mjs', '.cjs'].includes(ext)
-      ? `${id.slice(0, -2)}ts`
-      : ext === '.jsx'
-        ? `${id.slice(0, -3)}tsx`
-        : null;
-
-    if (!newId) {
-      throw error;
-    }
-    return resolveSync(newId, options.basedir);
+    const candidates =
+      ext === '.js'
+        ? [`${id.slice(0, -2)}ts`, `${id.slice(0, -2)}tsx`]
+        : ext === '.mjs'
+          ? [`${id.slice(0, -3)}mts`, `${id.slice(0, -3)}mtsx`]
+          : ext === '.cjs'
+            ? [`${id.slice(0, -3)}cts`, `${id.slice(0, -3)}ctsx`]
+            : ext === '.jsx'
+              ? [`${id.slice(0, -3)}tsx`]
+              : [];
+
+    for (const candidate of candidates) {
+      try {
+        return resolveSync(candidate, options.basedir);
+      } catch {
+        // Try the next interpreted extension.
+      }
+    }
+
+    throw error;
   }
 }

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@code/core/src/common/utils/interpret-files.ts` around lines 39 - 59, In
resolveImport, replace the single remap (newId) logic with trying all
TypeScript-related candidate extensions instead of one; when extname(id) is one
of '.js', '.mjs', '.cjs' or '.jsx' build a list of candidate replacements (e.g.
map '.js' family to ['.ts','.mts','.cts'] and '.jsx' to ['.tsx','.mts','.cts']
or use the module's supportedExtensions list) and iterate calling
resolveSync(candidateId, options.basedir) until one succeeds, returning the
resolved path; if none succeed rethrow the original caught error—use the
existing symbols resolveImport, resolveSync, extname and preserve the original
error behavior.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Outside diff comments:
In `@code/core/src/common/utils/interpret-files.ts`:
- Around line 39-59: In resolveImport, replace the single remap (newId) logic
with trying all TypeScript-related candidate extensions instead of one; when
extname(id) is one of '.js', '.mjs', '.cjs' or '.jsx' build a list of candidate
replacements (e.g. map '.js' family to ['.ts','.mts','.cts'] and '.jsx' to
['.tsx','.mts','.cts'] or use the module's supportedExtensions list) and iterate
calling resolveSync(candidateId, options.basedir) until one succeeds, returning
the resolved path; if none succeed rethrow the original caught error—use the
existing symbols resolveImport, resolveSync, extname and preserve the original
error behavior.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 82dc3e88-53cf-469f-8662-22291378004e

📥 Commits

Reviewing files that changed from the base of the PR and between a1393f1 and c63e535.

📒 Files selected for processing (2)

• code/core/src/common/utils/interpret-files.ts
• code/core/src/mocking-utils/resolve.ts

[Sidnioulz]

LGTM, but check the comment on extensions. We might need to do more to support community frameworks.