flow-debugginglisted

# Flow Debugging - Systematic Debugging Method ## The Iron Law ``` NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST ``` Bug fixing is not a guessing game. Systematic debugging = faster fixes + fewer regressions. ## The 4-Phase Process ``` Phase 1: ROOT CAUSE INVESTIGATION (NO FIXES YET) ↓ Phase 2: PATTERN ANALYSIS ↓ Phase 3: HYPOTHESIS AND TESTING ↓ Phase 4: IMPLEMENTATION (TDD) ``` ## Phase 1: Root Cause Investigation **Iron Law**: In this phase, **NO FIX CODE ALLOWED**. ```yaml Step 1: Read Error Completely - Don't skip any details - Record: error type, message, stack trace - Record: when it happens, frequency, impact Step 2: Stable Reproduction - Find reliable reproduction steps - Record: inputs, environment, preconditions - If can't reproduce → gather more information Step 3: Check Recent Changes - git log --oneline -20 - git diff HEAD~5 - Ask: What changed? When did it start failing? Step 4: Trace Data Flow Backwards - Start from error point - Trace upstream - Find where data goes wrong ``` **Output**: Root cause hypothesis (evidence-based, not a guess) ## Phase 2: Pattern Analysis ```yaml Step 1: Find Working Examples - Where does similar functionality work? - Compare: working vs broken Step 2: Compare with Reference - What does official documentation say? - How do other projects do it? - What's different? Step 3: Identify Patterns - Is this a known bug pattern? - Search: error message + framework name ```