Okojo Test262

Use this skill only for Test262-driven work in tools/Test262Runner and the engine/test files needed to resolve a selected Test262 failure. Ordinary engine work belongs to the general Okojo development workflow.

Core policy

Fix standards-aligned behavior.

Do not prioritize deprecated/legacy behavior unless explicitly re-approved. Treat these as intentionally unsupported by default:

• direct-eval-specific semantics
• with
• legacy __proto__
• deprecated legacy accessor APIs
• Function.prototype.arguments / Function.prototype.caller
• arguments.callee

For these, prefer narrow intended Test262 skips with a clear reason over regressing core paths.

Do not add a skip merely to make a run green. A skip requires an intentionally unsupported feature or an explicit user decision.

Workflow

1. reproduce the exact Test262 case
2. classify it as engine/compiler/runtime behavior or intentionally unsupported coverage
3. compare V8 for language/compiler/VM behavior or Node for built-in/runtime behavior
4. implement the narrow root-cause fix
5. add a focused regression under tests/Okojo.Tests
6. rebuild the runner before trusting an exact rerun
7. rerun the exact case, nearby coverage, and the requested continuation batch

Focused engine loop

dotnet build tests/Okojo.Tests/Okojo.Tests.csproj -c Release /p:UseSharedCompilation=false
dotnet test tests/Okojo.Tests/Okojo.Tests.csproj -c Release --no-build --filter <Name>

When the runner is involved:

dotnet build tools/Test262Runner/Test262Runner.csproj -c Release /p:UseSharedCompilation=false

Test262 runner

Show help:

dotnet run --project tools/Test262Runner/Test262Runner.csproj -c Release -- --help

Common continuation pattern:

dotnet run --project tools/Test262Runner/Test262Runner.csproj -c Release -- --max-tests 30 --full-path --skip-passed

Array.prototype sweep example:

dotnet run --project tools/Test262Runner/Test262Runner.csproj -c Release -- --max-tests 30 --category built-ins --filter Array/prototype --full-path --skip-passed

Useful runner notes:

• --skip-passed uses the local passed cache
• rebuild the runner after runtime/compiler changes before trusting exact reruns
• SkipList.cs contains intentional exclusions
• do not run a broad sweep when an exact or category-filtered rerun answers the current question

Editing guidance

• Prefer minimal, local fixes.
• Add a focused regression test for each fix.
• Do not revert unrelated user changes.
• Do not widen policy support accidentally just to satisfy a single Test262 file.