Open Service: Mark module-graph engine commands as internal

[JReinhold]

Closes #

What I did

Marked the module-graph open-service commands that are only used by the module graph engine as internal operations, following open-service conventions (internal: true and _-prefixed names):

• _applyGraphSnapshot
• _applyGraphUpdate
• _bumpGraphRevision
• _setStatus
• _waitForSettledEngine

Updated the service definition, server registration, and unit tests accordingly. Public queries (getStoriesForFiles, getStatus, getGraphRevision, getLatestStoryChanges) are unchanged.

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

Manual testing

Caution

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

No manual testing is necessary. This is an internal API naming and visibility change for engine-only open-service commands; behavior is unchanged and covered by existing unit tests.

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

• Declare whether manual QA will be needed for this PR during the next release, through qa:needed or qa:skip

• 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
  • Internal module-graph service architecture reorganized to improve code organization and maintainability.
  • Test infrastructure updated to align with service restructuring.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 2e2d4010-14da-48d3-a34b-5645c0a232d3

📥 Commits

Reviewing files that changed from the base of the PR and between 135e436 and 9437e31.

📒 Files selected for processing (4)

• code/core/src/shared/open-service/services/module-graph/definition.ts
• code/core/src/shared/open-service/services/module-graph/module-graph.test-helpers.ts
• code/core/src/shared/open-service/services/module-graph/server.test.ts
• code/core/src/shared/open-service/services/module-graph/server.ts

---

📝 Walkthrough

Walkthrough

This PR renames five internal module-graph service commands to underscore-prefixed variants (_applyGraphSnapshot, _applyGraphUpdate, _bumpGraphRevision, _setStatus, _waitForSettledEngine), marking them as internal APIs. The service definition, runtime wiring, test setup, and comprehensive test suite are updated consistently to use the new identifiers.

Changes

Module-graph internal command refactor

Layer / File(s)	Summary
Service command definitions and getStatus query code/core/src/shared/open-service/services/module-graph/definition.ts	Five commands are renamed to underscore-prefixed variants in moduleGraphServiceDef. The getStatus query load is updated to invoke ctx.self.commands._waitForSettledEngine(undefined) instead of the previous variant. Command handlers remain functionally identical; only the command identifiers change.
Service wiring and test harness setup code/core/src/shared/open-service/services/module-graph/server.ts, code/core/src/shared/open-service/services/module-graph/module-graph.test-helpers.ts	registerModuleGraphService updates all command invocations to use the renamed _-prefixed commands when calling snapshot/update/revision/status handlers. The test helper registerTestModuleGraphService registers a no-op handler under the _waitForSettledEngine key.
Test suite validation code/core/src/shared/open-service/services/module-graph/server.test.ts	All test cases throughout the file are updated to drive state transitions using the renamed internal commands (_applyGraphSnapshot, _applyGraphUpdate, _bumpGraphRevision, _setStatus). Test assertions for initial state seeding, reverse-index replacement, revision scoping, latest change tracking, and subscriptions remain unchanged.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

Possibly related PRs

• storybookjs/storybook#35048: Introduces the module-graph open-service feature that this PR modifies to mark internal commands with underscore prefix.
• storybookjs/storybook#35057: Establishes naming conventions requiring underscore prefixes for internal operations, which this PR applies to module-graph commands.
• storybookjs/storybook#35106: Updates command routing in query load execution paths, related to the getStatus query load change in this PR.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[storybook-app-bot]

Package Benchmarks

^{Commit: 9437e31, ran on 11 June 2026 at 16:53:57 UTC}

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

@storybook/builder-webpack5

	Before	After	Difference
Dependency count	184	184	0
Self size	79 KB	79 KB	0 B
Dependency size	33.98 MB	34.02 MB	🚨 +44 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/angular

	Before	After	Difference
Dependency count	185	185	0
Self size	160 KB	160 KB	0 B
Dependency size	31.32 MB	31.35 MB	🚨 +32 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/ember

	Before	After	Difference
Dependency count	189	189	0
Self size	15 KB	15 KB	0 B
Dependency size	30.80 MB	30.84 MB	🚨 +44 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/nextjs

	Before	After	Difference
Dependency count	534	534	0
Self size	662 KB	662 KB	🎉 -120 B 🎉
Dependency size	62.16 MB	62.21 MB	🚨 +44 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/react-webpack5

	Before	After	Difference
Dependency count	271	271	0
Self size	23 KB	23 KB	0 B
Dependency size	46.70 MB	46.74 MB	🚨 +44 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/server-webpack5

	Before	After	Difference
Dependency count	196	196	0
Self size	16 KB	16 KB	0 B
Dependency size	35.24 MB	35.29 MB	🚨 +44 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/preset-react-webpack

	Before	After	Difference
Dependency count	164	164	0
Self size	18 KB	18 KB	0 B
Dependency size	32.48 MB	32.53 MB	🚨 +44 KB 🚨
Bundle Size Analyzer	Link	Link