Code Reuse Enforcement

CRITICAL GUARDRAIL: Discover existing code BEFORE writing new code.

Why This Matters

• Magic strings scatter across 50 files instead of 1 constant
• Duplicate utilities create maintenance nightmares
• Inconsistent values break features silently

The Discovery-First Workflow

BEFORE writing ANY code with literals or utilities:

1. Check Constants – URLs, paths, timeouts, limits, env var names
2. Check Enums – States, statuses, types, actions
3. Check Utilities – Path ops, env reading, file ops, validation

Quick Reference: discovery-catalog.md

Common Violations

Magic Strings

# ❌ BAD
url = "https://ai-debugger.com/support"
log_dir = ".aidb/log"
debug = os.getenv("AIDB_LOG_LEVEL", "INFO")

# ✅ GOOD
from aidb_common.constants import AIDB_BASE_URL
from aidb_common.path import get_aidb_log_dir
from aidb_logging.utils import get_log_level

url = f"{AIDB_BASE_URL}/support"
log_dir = get_aidb_log_dir()
log_level = get_log_level(default="INFO")

Magic Numbers

# ❌ BAD
await asyncio.sleep(0.1)
timeout = 5.0

# ✅ GOOD
from aidb.common.constants import EVENT_POLL_TIMEOUT_S, CONNECTION_TIMEOUT_S

await asyncio.sleep(EVENT_POLL_TIMEOUT_S)
timeout = CONNECTION_TIMEOUT_S

Reimplementing Utilities

# ❌ BAD
def get_bool_env(name: str, default: bool) -> bool:
    value = os.getenv(name)
    return value.lower() in ("true", "1", "yes") if value else default

# ✅ GOOD
from aidb_common.env import read_bool
result = read_bool("AIDB_TRACE", default=False)

String States

# ❌ BAD
if session_state == "running":
    pass

# ✅ GOOD
from aidb_mcp.core.constants import SessionState
if session_state == SessionState.RUNNING:
    pass

Quick Discovery

Constants Files

Utility Packages

Full reference: See docstrings in src/aidb_common/

Search Commands

grep -r "value_to_find" src --include="*.py"
find src -name "constants.py"
grep -r "class.*Enum" src --include="*.py" -l

When to Create NEW Constants

Only when:

1. Truly new concept – Not covered by existing constants
2. Used 2+ times – Will be reused
3. Proper location – Adding to the RIGHT constants file
4. Following patterns – Matches existing naming conventions

Enforcement Checklist

Before committing:

• No hardcoded URLs (use aidb_common constants)
• No hardcoded paths (use path utilities)
• No magic numbers for timeouts (use api/constants.py)
• No string literals for states (use enums)
• No reimplemented utilities (check aidb_common)
• No manual env var parsing (use aidb_common.env)

Resources

• Discovery Catalog – Complete constants, enums, utilities reference
• src/aidb_common/ – Source code with detailed docstrings