CodeSampleX

Sample

convert 3.1.2: Configure fallback handling and validation bounds for unmapped characters and undefined byte sequences in CodePage

Verified sample for pub convert 3.1.2: Configure fallback handling and validation bounds for unmapped characters and undefined byte sequences in CodePage.…

sha256:e790c49d1fb497727a63db0bd94d5804512cbd6739117627ea6133dbbbd06ad9

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 dart linux x64 dart dart pub

Verification-run environments

Environment Contract Stages Run
dart 3 · linux debian/x64 · docker ed25519:d91480838ac982c9 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · pub@1
2026-08-17
dart 3 · linux debian/x64 · docker ed25519:2175b912ea1c23b1 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · pub@1
2026-08-18

Case

HOW
Goal
Configure fallback handling and validation bounds for unmapped characters and undefined byte sequences in CodePage
Packages
Symbols
  • CodePage
  • CodePage.encode
  • CodePage.decode
  • latin2
Environment
dart
Created
2026-08-17T13:02:57Z

Contract

  1. CodePage.encode throws FormatException on unmapped characters unless configured with an in-range invalidCharacter byte, and CodePage.decode throws FormatException on undefined byte entries unless allowInvalid is set to true.
  2. latin2.encode('Price: 10€') throws FormatException because the Euro symbol is unmapped in ISO-8859-2.
  3. latin2.encode('Price: 10€', invalidCharacter: 0x3F) succeeds and substitutes the question mark byte 0x3F for the unmapped Euro character.
  4. latin2.encode('Price: 10€', invalidCharacter: 256) throws RangeError because invalidCharacter must be an integer within 0..255.
  5. latin2.decode([0x50, 0x80, 0x51]) throws FormatException because 0x80 is an undefined code point in ISO-8859-2.
  6. latin2.decode([0x50, 0x80, 0x51], allowInvalid: true) succeeds and emits Unicode replacement character U+FFFD for 0x80.
  7. latin2.decode([256]) throws FormatException with 'Not a byte value' while allowInvalid: true emits U+FFFD.
  8. CodePage('custom', 'ABC') throws ArgumentError because CodePage table definitions require exactly 256 characters.

Files

  • NOTES.md
  • csx.json
  • pubspec.lock
  • pubspec.yaml
  • test/contract.dart

Download the source artifact (tar.gz)

Origin Seeder

csx-seed