# Hako Check — Diagnostics Contract (MVP)

This tool lints .hako sources and emits diagnostics.

Diagnostics schema (typed)
- Map fields:
  - `rule`: string like "HC011"
  - `message`: string (human-readable, one line)
  - `file`: string (path)
  - `line`: int (1-based)
  - `severity`: string ("error"|"warning"|"info"), optional (default: warning)
  - `quickFix`: string, optional

Backwards compatibility
- Rules may still `out.push("[HCxxx] ...")` with a single-line string.
- The CLI accepts both forms. String diagnostics are converted to typed internally.

Suppression policy
- HC012 (dead static box) takes precedence over HC011 (unreachable method).
- If a box is reported by HC012, HC011 diagnostics for methods in that box are suppressed at aggregation.

Quiet / JSON output
- When `--format json-lsp` is used, output is pure JSON (pretty). Combine with `NYASH_JSON_ONLY=1` in the runner to avoid extra lines.
- Non-JSON formats print human-readable lines per finding.

Planned AST metadata (parser_core.hako)
- `boxes[].span_line`: starting line of the `static box` declaration.
- `methods[].arity`: parameter count as an integer.
- `boxes[].is_static`: boolean.

Notes
- Prefer AST intake; text scans are a minimal fallback.
- For tests, use `tools/hako_check/run_tests.sh`.

Analyzer policy (plugins)
- Tests/CI/Analyzer run without plugins by default: `NYASH_DISABLE_PLUGINS=1` and `NYASH_JSON_ONLY=1`.
- File I/O is avoided by passing source text via `--source-file <path> <text>`.
- When plugins are needed (dev/prod), set `NYASH_FILEBOX_MODE=auto` and provide [libraries] in nyash.toml.

Default test env (recommended)
- `NYASH_DISABLE_PLUGINS=1` – avoid dynamic plugin path and noise
- `NYASH_BOX_FACTORY_POLICY=builtin_first` – prefer builtin/ring‑1 for stability
- `NYASH_DISABLE_NY_COMPILER=1` and `HAKO_DISABLE_NY_COMPILER=1` – disable inline compiler in tests
- `NYASH_JSON_ONLY=1` – stdout is pure JSON (logs go to stderr)

## Known Limitations

### HC017: Non-ASCII Quotes Detection (Temporarily Skipped)

**Status**: ⏸️ Skipped until UTF-8 support is available

**Reason**: This rule requires UTF-8 byte-level manipulation to detect smart quotes (" " ' ') in source code. Nyash currently lacks:
- Byte array access for UTF-8 encoded strings
- UTF-8 sequence detection capabilities (e.g., detecting 0xE2 0x80 0x9C for ")
- Unicode character property inspection methods

**Technical Requirements**: One of the following implementations is needed:
- Implement `ByteArrayBox` with UTF-8 encoding/decoding methods (`to_bytes()`, `from_bytes()`)
- Add built-in Unicode character property methods to `StringBox` (e.g., `is_ascii()`, `char_code_at()`)
- Provide low-level byte access methods like `string.get_byte(index)` or `string.byte_length()`

**Re-enable Timeline**: Planned for **Phase 22** (Unicode Support Phase) or when ByteArrayBox lands

**Test Files**:
- [`tests/HC017_non_ascii_quotes/ng.hako`](tests/HC017_non_ascii_quotes/ng.hako) - Contains intentional smart quotes for detection testing
- [`tests/HC017_non_ascii_quotes/ok.hako`](tests/HC017_non_ascii_quotes/ok.hako) - Clean code without smart quotes (baseline)
- [`tests/HC017_non_ascii_quotes/expected.json`](tests/HC017_non_ascii_quotes/expected.json) - Empty diagnostics (reflects disabled state)

**Implementation File**: [`rules/rule_non_ascii_quotes.hako`](rules/rule_non_ascii_quotes.hako) - Currently returns 0 (disabled) in `_has_fancy_quote()`

**Current Workaround**: The test is automatically skipped in `run_tests.sh` to prevent CI failures until UTF-8 support is implemented.

---

Rules
- Core implemented (green): HC011 Dead Methods, HC012 Dead Static Box, HC015 Arity Mismatch, HC016 Unused Alias, HC018 Top‑level local, HC021 Analyzer IO Safety, HC022 Stage‑3 Gate, HC031 Brace Heuristics
- Temporarily skipped: HC017 Non‑ASCII Quotes (UTF-8 support required)
- Pending fixtures update: HC013 Duplicate Method, HC014 Missing Entrypoint

CLI options
- `--rules a,b,c` limit execution to selected rules.
- `--skip-rules a,b` skip selected.
- `--no-ast` (default) avoids AST parser; `--force-ast` enables AST path (use sparingly while PHI is under polish).

Tips
- JSON-only output: set `NYASH_JSON_ONLY=1` to avoid log noise in stdout; diagnostics go to stdout, logs to stderr.
- For multiline `--source-file` payloads, CLI also provides HEX-escaped JSON in `NYASH_SCRIPT_ARGS_HEX_JSON` for robust transport; the VM prefers HEX→JSON→ARGV.
