nemesia

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Changelog ​

All notable changes to Nemesia are documented here.

2.2.2 — 2026-09-26 ​

Fixed ​

  • With observation, find and findAll include markup inserted earlier in the same task and exclude roots removed in it.
  • With observation, destroy(scope) also destroys roots inserted into the scope earlier in the same task.

2.2.0 — 2026-09-25 ​

Added ​

  • find and findAll on components and apps return mounted instances of a component class, typed from the class.
  • A data-ref placed on a nested component root belongs to the component above it.

Breaking changes ​

  • The ESM build exports Component, DistributedComponent and createApp by name. The Nemesia namespace object exists only in the UMD build.
  • Within one mount, every component is constructed first; onMount then runs for nested components before their parents, and for distributed components last.
  • DistributedComponent(name) no longer takes an options argument.
  • this.ref and this.option methods live on the prototype, so they cannot be destructured.
  • When a singleton's onMount fails, candidates skipped in its favor mount on the next mount() call.

Performance ​

  • Mounting is about twice as fast and each mounted component uses about 70% less memory.
  • Ref lookups use native attribute selectors, which makes components with large subtrees up to eight times faster to mount.

Fixed ​

  • Number literal options compare with strict equality.

2.1.0 — 2026-09-25 ​

Added ​

  • this.on types known DOM events from the target and event name. Custom events receive Event unless the listener parameter is annotated.

Breaking changes ​

  • An empty number option is invalid instead of 0.
  • Required option helpers no longer accept default.

Fixed ​

  • destroy(scope) destroys roots that were removed from the scope before the call.
  • disconnect() processes removals that the observer has not delivered yet.
  • An AbortError rejected by onMount after destroy is not reported.

Performance ​

  • Mutations that add or remove no elements skip ancestry bookkeeping.

2.0.1 — 2026-07-12 ​

  • Documentation comments for public methods and properties.

2.0.0 — 2026-07-07 ​

  • Complete rewrite: class components with typed refs and options, distributed components, DOM contract validation and optional observation of dynamic DOM.

1.1.3 — 2026-04-09 ​

  • More detailed warnings.
  • Optional schema.options in defineComponent.

1.1.2 — 2026-04-09 ​

  • Computed values.
  • Multiple component instances on a single element.

1.0.3 — 2026-04-02 ​

  • Untagged refs fall back to HTMLElement.
  • Best practices chapter in the documentation.

1.0.0 — 2026-03-30 ​

  • Initial release.