Test Coverage Assessment

Summary

Verdict: Test coverage is adequate for this change.

This PR moves exit code constants from tools/jtk/internal/exitcode to shared/exitcode and updates both cfl and jtk to use the shared package.

Analysis

What Changed:

1. Created shared/exitcode/exitcode.go - a package of constant integer definitions
2. Updated tools/cfl/cmd/cfl/main.go to use exitcode.GeneralError instead of hardcoded 1
3. Updated tools/jtk/cmd/jtk/main.go to import from the shared package instead of the internal one
4. Deleted tools/jtk/internal/exitcode/exitcode.go

Why Tests Are Not Required:

1. Pure Constants: The exitcode package contains only constant definitions (const Success = 0, const GeneralError = 1, etc.). These are compile-time values with no logic, branching, or behavior to test. Testing that GeneralError == 1 would be tautological.

2. No Behavior to Verify: Unlike the shared/errors package (which has parsing, formatting, and error wrapping logic), exitcode has no methods, no state, and no transformation logic.

3. Deleted Package Had No Tests: The original tools/jtk/internal/exitcode package had no tests, and that was appropriate for the same reason - it's just constants.

4. Integration Verified by Build: The PR's test plan confirms the build succeeds, meaning the import paths are correct and the constants are accessible. This is the meaningful verification for a constants-only package.

For Reference:
The existing test suites for cfl and jtk will continue to exercise code paths that use these exit codes. If any constant were incorrectly defined, existing tests exercising error handling would fail.

Verdict

No additional tests needed. The change is a straightforward refactor to share constants between tools, and the existing CI pipeline (build + existing tests) provides sufficient verification.