Sample
express 5.2.1: Handle Express request header evaluation boundaries across req.is body presence, req.accepts zero-weight quality factors, req.range numeric sentinel codes, and req.get empty-string validation
Verified sample for npm express 5.2.1: Handle Express request header evaluation boundaries across req.is body presence, req.accepts zero-weight quality…
sha256:e74ad98b97d3ae7856fa4fd5b676002a0036a58f77d64b678a2ecb9d6561a100
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
- Handle Express request header evaluation boundaries across req.is body presence, req.accepts zero-weight quality factors, req.range numeric sentinel codes, and req.get empty-string validation
- Packages
- Symbols
-
- req.is
- req.accepts
- req.acceptsEncodings
- req.range
- req.get
- Environment
- node
- Created
- 2026-08-17T01:50:52Z
Contract
- req.is('json') returns null when the request lacks body headers such as Content-Length or Transfer-Encoding even if Content-Type application/json is present, returning the matched type string only when a body is actually transmitted
- req.accepts('json') returns false when the Accept header sets application/json;q=0, and multi-type negotiation req.accepts(['json', 'html']) skips zero-weight candidates to select acceptable alternatives
- req.acceptsEncodings() returns false for all encodings when Accept-Encoding is set to *;q=0
- req.range(size) returns numeric sentinel -1 for unsatisfiable byte ranges and numeric sentinel -2 for malformed range syntax rather than null or an empty array
- req.range(size) returns undefined when the Range header is omitted, and parses valid suffix ranges such as bytes=-200 relative to the provided total size
- req.get('') and req.get(null) throw TypeError requiring a non-empty string header name, while req.get('referrer') automatically aliases to the HTTP Referer header
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- test/contract.mjs