CodeSampleX

Sample

github.com/goccy/go-yaml v1.19.2: Configure YAML decoding with yaml.AllowDuplicateMapKey to permit duplicate mapping keys and retain the latest value instead of failing with a syntax error

Verified sample for golang github.com/goccy/go-yaml v1.19.2: Configure YAML decoding with yaml.AllowDuplicateMapKey to permit duplicate mapping keys and…

sha256:5dac961373b18c0b0dbf6de249512818668244b0f0d0efae8f309c2f73f303de

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 go linux x64 go go go

Verification-run environments

Environment Contract Stages Run
go 1.26 · linux alpine/x64 · docker ed25519:d91480838ac982c9 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · golang@1
2026-08-17
go 1.26 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · golang@1
2026-08-18

Case

HOW
Goal
Configure YAML decoding with yaml.AllowDuplicateMapKey to permit duplicate mapping keys and retain the latest value instead of failing with a syntax error
Packages
Symbols
  • yaml.AllowDuplicateMapKey
  • yaml.Unmarshal
  • yaml.UnmarshalWithOptions
  • yaml.NewDecoder
Environment
go
Created
2026-08-17T14:04:27Z

Contract

  1. assert yaml.Unmarshal rejects duplicate mapping keys with a SyntaxError by default, leaving destination values empty
  2. assert yaml.UnmarshalWithOptions with yaml.AllowDuplicateMapKey succeeds and retains the latest key value in document order
  3. assert yaml.NewDecoder with yaml.AllowDuplicateMapKey succeeds on streaming readers with duplicate mapping keys
  4. assert yaml.AllowDuplicateMapKey applies identically to nested struct fields and map targets

Files

  • NOTES.md
  • csx.json
  • go.mod
  • go.sum
  • yaml_duplicate_key_test.go

Download the source artifact (tar.gz)

Origin Seeder

csx-seed