feat(dev-server): /@ng/component endpoint + HMR runtime bus (#145) - #186
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lukekania merged 2 commits intoJun 9, 2026
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First slice of Hot Module Replacement: read the `hmr` flag and hot-swap
global stylesheets in place without a full page reload.
- project-resolver: parse `architect.serve.options.hmr` (base + active
serve configuration override) into `ResolvedAngularProject.hmr`;
defaults to false.
- cli: add `--hmr` / `--no-hmr` to `serve` (CLI wins over angular.json,
else inherit, else false). When HMR is on and a rebuild touches only
global stylesheet entries, emit a CSS-update instead of a reload.
- dev-server: new `DevServerEvent::CssUpdate { timestamp }` →
`event: css-update` SSE frame; the injected client swaps the
`styles.css` <link> with a cache-busted href, preserving page state.
Component template/style HMR and the `/@ng/component` update endpoint
land in follow-up slices on the milestone branch.
Runtime scaffolding for component-level HMR, ahead of the compiler
codegen that populates it.
- dev-server: new `DevServerEvent::ComponentUpdate { id, timestamp }` →
`event: angular:component-update` SSE frame; a shared `ComponentUpdates`
registry (id → update-module source) on `DevServerConfig`, served at
`GET /@ng/component?c=<id>` (text/javascript, empty 200 for unknown ids,
400 when `c` is absent) — mirrors @angular/build's component middleware.
- client: the injected script publishes a `window.__ngcHmr` bus and
dispatches `angular:component-update` to registered handlers; new
`HMR_RUNTIME_PRELUDE` binds `import.meta.hot` to that bus.
- serve: share the registry with the dev server and prepend the runtime
prelude to `main.js` on each HMR build so per-component initializers can
resolve `import.meta.hot`.
The registry stays empty and component edits still trigger a full reload
until the template-compiler emits update modules (next slice).
lukekania
changed the base branch from
feat/hmr-config-css-swap
to
milestone/v0.11.0-builder-parity
June 9, 2026 14:09
This was referenced Jun 10, 2026
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Runtime scaffolding for component-level HMR (#145), ahead of the compiler codegen that populates it. Stacked on #185.
Changes
DevServerEvent::ComponentUpdate { id, timestamp }→event: angular:component-updateSSE frame; a sharedComponentUpdatesregistry (id → update-module source) onDevServerConfig, served atGET /@ng/component?c=<id>(text/javascript, empty200for unknown ids,400whencis absent) — mirrors@angular/build's component middleware.window.__ngcHmrbus and dispatchesangular:component-updateto registered handlers; newHMR_RUNTIME_PRELUDEbindsimport.meta.hotto that bus.import.meta.hot.Scope
The registry stays empty and component edits still trigger a full reload until the template-compiler emits update modules (next slice, stacked on this branch).
Tests
angular:component-updateSSE frame shape;query_paramraw-encoded extraction;/@ng/componentendpoint (registered id → module, unknown → empty 200, missingc→ 400); client exposes the__ngcHmrbus + prelude.Targets the milestone branch via the stack; retarget to it once #185 merges.