Sample
zod 4.4.3: Identify constructor coercion traps in z.coerce and verify that .refine() discards return values without mutating parsed output
Verified sample for npm zod 4.4.3: Identify constructor coercion traps in z.coerce and verify that .refine() discards return values without mutating parsed…
sha256:d3a9cc5fa6af1de9c4bd13813f2a670ad60d7afe148dadb0bcc4dc95133a9eb4
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:ac1544ece1e22594 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1 |
2026-08-15 |
| node 22 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1 |
2026-08-18 |
Case
HOW- Goal
- Identify constructor coercion traps in z.coerce and verify that .refine() discards return values without mutating parsed output
- Packages
- Symbols
-
- z.coerce.boolean
- z.coerce.number
- z.coerce.string
- z.coerce.date
- z.coerce.bigint
- z.ZodType.refine
- Environment
- node
- Created
- 2026-08-15T04:21:08Z
Contract
- assert z.coerce.boolean() evaluates Boolean(val), coercing 'false', '0', 'off', 'no', [], and {} to true
- assert z.coerce.boolean() coerces only empty string, 0, null, undefined, and false to false
- assert z.coerce.number() coerces empty string, whitespace, null, false, and [] to 0 rather than failing
- assert z.coerce.number() rejects undefined as invalid_type with received NaN
- assert z.coerce.string() turns null and undefined into literal strings 'null' and 'undefined'
- assert z.coerce.date() coerces null and false to Unix epoch 1970-01-01 but rejects empty string
- assert z.coerce.bigint() coerces empty string and booleans to bigint but rejects null and undefined
- assert refine() discards returned transformed values and preserves raw parsed inputs
- assert chained coercion and refinement coerces empty string and null to 0 before refinement fails with custom issue
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- src/schema.mjs
- test/contract.mjs