Okojo Test262

Use this skill for work under:

• src/Okojo
• tests/Okojo.Tests
• docs/
• tools/OkojoBytecodeTool
• tools/V8BytecodeTool
• tools/Test262Runner

Primary priorities

1. correctness
2. observability/tooling
3. measured optimization

Prefer:

• V8 as the reference for language/compiler/VM behavior
• Node as the reference for built-in/runtime API behavior

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.

Required workflow for non-trivial debugging

1. inspect emitted Okojo bytecode
2. inspect VM/runtime behavior
3. inspect V8 / Node behavior
4. record short findings: copy vs intentional difference

Tools:

• tools/OkojoBytecodeTool
• tools/V8BytecodeTool
• node -e ...
• sandbox/OkojoRepl

Fast local 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

Skip list location:

• tools/Test262Runner/SkipList.cs

Implementation guidance

• Keep hot paths simple.
• Push uncommon semantics into explicit slow paths.
• Keep frame layout and opcode operand conventions stable.
• Keep numeric index keys out of shape transitions.

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.

Commit discipline

git status --short
git add src/Okojo/... tests/Okojo.Tests/... tools/... docs/...
git commit -m "<type>(<scope>): <subject>"

Do not commit unrelated IDE files, experiments, or non-Okojo changes.

Focused references

Use the matching doc note when a feature has an active work note in docs/.