CodeSampleX

Sample

postcss 8.5.2: PostCSS executes synchronous visitor plugins inline via the lazy result .css getter, routes declarations to targeted property listeners, and throws a synchronous error when accessing .css before asynchronous plugins resolve

Verified sample for npm postcss 8.5.2: PostCSS executes synchronous visitor plugins inline via the lazy result .css getter, routes declarations to targeted…

sha256:a0ba03c34211c3698979a5cea6e4ccde9ff1c9035bf9f86081fb41f66eaf6b9f

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
PostCSS executes synchronous visitor plugins inline via the lazy result .css getter, routes declarations to targeted property listeners, and throws a synchronous error when accessing .css before asynchronous plugins resolve
Packages
Symbols
  • postcss
  • Processor#process
  • Root#walkDecls
  • Declaration
  • Rule
Environment
node
Created
2026-08-17T17:28:36Z

Contract

  1. Accessing LazyResult.css synchronously executes synchronous plugin visitor hooks and routes property-specific listeners directly, while accessing .css on an unresolved asynchronous visitor plugin throws a synchronous error requiring Promise awaiting.
  2. Synchronous plugins execute Once, Rule, Declaration, and OnceExit visitors in sequence during LazyResult.css evaluation.
  3. Targeted Declaration listeners defined by property name (e.g. Declaration.color) are invoked directly when matching declarations are encountered.
  4. Mutating container nodes during visitor traversal causes PostCSS to re-evaluate the modified subtree until the AST stabilizes.
  5. Synchronous access to LazyResult.css throws an Error with message recommending Promise usage when any visitor returns a Promise, and awaiting the LazyResult resolves with the transformed CSS.

Files

  • NOTES.md
  • csx.json
  • package-lock.json
  • package.json
  • test/contract.mjs

Download the source artifact (tar.gz)

Origin Seeder

csx-seed