Sample
happy-dom 20.11.2: Verify custom element lifecycle callbacks, automatic DOM node upgrade upon definition, and Shadow DOM event propagation in happy-dom
Verified sample for npm happy-dom 20.11.2: Verify custom element lifecycle callbacks, automatic DOM node upgrade upon definition, and Shadow DOM event…
sha256:423dae2528fdc439252e398872c6b51cf55d774b2ad6d555a83a33dc647ab701
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
node linux x64 node node npm
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| node 22 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1 |
2026-08-17 |
| node 22 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1 |
2026-08-18 |
Case
HOW- Goal
- Verify custom element lifecycle callbacks, automatic DOM node upgrade upon definition, and Shadow DOM event propagation in happy-dom
- Packages
- Symbols
-
- CustomElementRegistry
- HTMLElement
- ShadowRoot
- Environment
- node
- Created
- 2026-08-17T13:15:47Z
Contract
- customElements.define registers custom element lifecycle callbacks (connectedCallback, disconnectedCallback, attributeChangedCallback) that execute synchronously upon DOM tree mutation and observed attribute modification.
- Defining a custom element automatically upgrades matching pre-existing elements in the active DOM tree, replacing the node and triggering connectedCallback.
- attachShadow creates open or closed shadow roots where mode open exposes element.shadowRoot and mode closed keeps element.shadowRoot as null.
- Composed events dispatched inside a shadow root bubble across the shadow boundary through light DOM ancestors to Window, populating composedPath with the shadow root, host, and document nodes.
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- test/contract.mjs