Sample
Assert React 19.0.0 element construction, transitional symbol typing, ref-as-prop placement, self-referencing context providers, cloneElement immutability, and hierarchical Children tree traversal
sha256:c8b98eea95c66b47e111cdc80a70e476f4d7403393566d55915970c58faaaf08
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Execution evidence
Declared environment and signed verification runs are separated so you can see exactly what this sample proves.
Evidence basisSigned contract pass
Verification receipts1
Verification levelL3_CONTRACT_PASS
Declared environment
- Execution context
- node
- Operating system
- linux
- Architecture
- x64
- Runtime
- node
- Language
- node
- Package manager
- npm
Verification-run environments
- Execution context
- node 22
- Operating system
- linux alpine · musl
- Architecture
- x64
- Runtime
- node 22
- Language
- javascript
- Package manager
- npm
- Execution
- container · docker
CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17
Case
- Goal
- Assert React 19.0.0 element construction, transitional symbol typing, ref-as-prop placement, self-referencing context providers, cloneElement immutability, and hierarchical Children tree traversal HOW
- Packages
-
react 19.0.0
- Environment
- node
- Created
- 2026-08-17T20:12:28Z
Contract
- React 19 createElement produces elements with Symbol.for('react.transitional.element') typeof where ref is stored directly as a prop on props.ref rather than an element property.
- React.isValidElement returns true for elements constructed with transitional element symbols and false for legacy element symbols, plain objects, or primitives.
- React.cloneElement shallowly copies and overrides props, replaces ref via props.ref, and preserves the original element immutability.
- React.createContext returns a context object where Provider is a self-reference to the context instance itself.
- React.Children.toArray flattens nested arrays, strips null and boolean elements, and prepends hierarchical traversal path prefixes to keys.
- React.Children.count tallies every child slot across nested structures including null and booleans while Children.only asserts a single child element.
- React.Children.map strips null returns, flattens array returns, and passes through null or undefined roots as null or undefined.
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- test/contract.mjs
Download the source artifact (tar.gz)
Origin Seeder
csx-seed
Verification receipts
- node 22 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-17 · ed25519:d91480838ac982c9