fix(config): tolerate trailing commas in micode.json and warn on parse errors

[nitoba]

Summary

Add stripTrailingCommas helper with a string-safe regex that skips quoted values, preventing corruption of strings like "hello, }"
Apply trailing-comma tolerance to all three JSON.parse call sites (opencode.json, micode.json, model context limits)
Distinguish file-not-found (silent) from actual parse errors in loadMicodeConfig — logs a clear warning via log.warn so users know their config was ignored

Problem

Hand-edited JSON configs commonly include trailing commas (e.g. "compactionThreshold": 0.8,). JSON.parse rejects this and throws. The catch block was silently returning null, causing all user overrides to be lost with zero feedback — users had no way to know their micode.json was being ignored.
Approach

Instead of adding a JSONC parser dependency, a lightweight regex strips trailing commas before parsing. The regex uses alternation ("..." | ,\s*[]}]) to match quoted strings first and return them unchanged, so values containing , } or , ] are never corrupted.

For truly invalid JSON (beyond trailing commas), the error is now surfaced via log.warn with the parse error message, while file-not-found remains silent as expected.
Test plan

Trailing commas in micode.json are tolerated and parsed correctly
String values containing , } and , ] are NOT corrupted by the sanitizer
Invalid JSON (beyond trailing commas) returns null and logs a warning
File-not-found remains silent (no warning spam)
All 90 config + agent tests pass

---

Summary by cubic

Tolerates trailing commas in JSON configs and warns on read/parse errors so user overrides aren’t silently ignored. Applies to micode.json, opencode.json, and model context limits.

• Bug Fixes
  • Strip trailing commas before parsing using a string-safe regex that leaves quoted text unchanged.
  • Apply parsing tolerance across all JSON reads: opencode.json, micode.json, and model context limits.
  • In loadMicodeConfig, keep file-not-found silent; warn on read failures (“Failed to read micode.json”) and on parse errors (“Failed to parse micode.json”).

^{Written for commit ef676ba. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 2 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="src/config-loader.ts">

<violation number="1" location="src/config-loader.ts:184">
P2: The warning message in loadMicodeConfig conflates read errors with parse errors; any non-ENOENT filesystem error is logged as “Failed to parse micode.json,” which is misleading and can send users to fix JSON when the issue is permissions/path/I/O.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[nitoba]

No fix needed. The error handling is already correctly separate @cubic-dev-ai

[vtemian]

Thanks for the contribution @nitoba! Good catch on the trailing commas issue.

This is superseded by #31 which added full JSONC support via jsonc-parser (the same library OpenCode uses). This covers trailing commas, line/block comments, and .jsonc file discovery — no regex needed.