[Unipro-DanMunn]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Tests (npm test) were run locally and passed
• Prettier (npm run prettier) was run locally and passed

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Since 2.2.2, src/subscriptions/stencil.ts copies the @stencil/core namespace into a variable (const core = StencilCore). Rollup then keeps the whole module object, so it can no longer fold Build.isBrowser to false in Stencil's hydrate build. Any browser-only module imported behind if (Build.isBrowser) is bundled into the hydrate app and runs when it loads, so renderToString can throw (for example document.createTreeWalker is not a function).

GitHub Issue Number: #760

What is the new behavior?

• forceUpdate and getRenderingRef are read straight off the namespace (StencilCore.forceUpdate), which Rollup resolves to the individual exports, so Build.isBrowser branches are removed from hydrate builds again.
• The namespace import from chore(tests): Upgrade vitest fixing the issues and increment test coverage #647 stays, so a @stencil/core without these exports still gets an empty subscription instead of a missing-export error.
• New test test/hydrate.test.ts: it bundles the store as it's published, installs it into a small Stencil app (test/hydrate-app) with a dist-hydrate-script output, builds that app, and checks that a module imported behind Build.isBrowser isn't in the hydrate app.

Does this introduce a breaking change?

• Yes
• No

Testing

• The new test fails on main (module imported behind Build.isBrowser was bundled into the hydrate app) and passes with this change.
• npm test: 65 tests pass, and Prettier reports no changes.
• I also ran the reproduction from bug: since 2.2.2, import * as StencilCore stops Rollup removing Build.isBrowser branches from the hydrate app #760 (https://github.com/Unipro-DanMunn/stencil-store-hydrate-repro, Stencil 4.45.2) against this branch's build. The browser-only module is no longer in hydrate/index.mjs, and renderToString succeeds and renders declarative shadow DOM.

Other information

The test installs the store into the fixture's node_modules instead of importing it from src, because the bug only reproduces when Stencil consumes the store as pre-built JavaScript. The fixture has its own package.json so TypeScript doesn't resolve @stencil/store to this repo's source through package self-reference.