feat(plugin): add TDD cycle mini progress bar in PreToolUse

packages/claude-code-plugin/hooks/lib/tdd_progress.py

@@ -0,0 +1,56 @@
+"""TDD cycle mini progress bar for status display (#1035).
+
+Builds a visual indicator showing current TDD phase progress:
+  [RED ● GREEN ○ REFACTOR ○]
+
+Reads phase from CODINGBUDDY_TDD_PHASE env var or explicit argument.
+"""
+import os
+from typing import Optional
+
+# TDD phases in sequential order
+TDD_PHASES = ["RED", "GREEN", "REFACTOR"]
+
+# Display symbols
+ACTIVE = "\u25cf"    # ●
+INACTIVE = "\u25cb"  # ○
+
+
+def build_tdd_indicator(
+    phase: Optional[str] = None,
+    cycle_count: Optional[int] = None,
+) -> Optional[str]:
+    """Build a one-line TDD cycle progress indicator.
+
+    Args:
+        phase: Current TDD phase (RED, GREEN, REFACTOR).
+               If None, reads from CODINGBUDDY_TDD_PHASE env var.
+        cycle_count: Number of completed TDD cycles. Appended as '#N'
+                     when > 0.
+
+    Returns:
+        Formatted string like '[RED ● GREEN ○ REFACTOR ○]' or None
+        if no valid phase is active.
+    """
+    if phase is None:
+        phase = os.environ.get("CODINGBUDDY_TDD_PHASE", "")
+
+    if not phase:
+        return None
+
+    phase = phase.upper().strip()
+    if phase not in TDD_PHASES:
+        return None
+
+    phase_index = TDD_PHASES.index(phase)
+    parts = []
+    for i, p in enumerate(TDD_PHASES):
+        symbol = ACTIVE if i <= phase_index else INACTIVE
+        parts.append(f"{p} {symbol}")
+
+    indicator = f"[{' '.join(parts)}]"
+
+    if cycle_count and cycle_count > 0:
+        indicator = f"{indicator} #{cycle_count}"
+
+    return indicator

packages/claude-code-plugin/hooks/pre-tool-use.py

@@ -25,6 +25,7 @@
 from config import get_config
 from agent_status import build_status_message
 from adaptive_perf import get_monitor
+from tdd_progress import build_tdd_indicator
 
 # Pattern to detect git commit in a command string
 _GIT_COMMIT_RE = re.compile(r"\bgit\s+commit\b")
@@ -179,6 +180,14 @@ def _handle(data: dict) -> Optional[dict]:
     # Build agent status message for spinner (#974) — applies to ALL tools
     status_msg = build_status_message()
 
+    # Append TDD cycle progress indicator (#1035)
+    tdd_indicator = build_tdd_indicator()
+    if tdd_indicator:
+        if status_msg:
+            status_msg = f"{status_msg} {tdd_indicator}"
+        else:
+            status_msg = tdd_indicator
+
     tool_name = data.get("tool_name", "")
     contexts = []
 

packages/claude-code-plugin/hooks/tests/test_tdd_progress.py

@@ -0,0 +1,87 @@
+"""Tests for tdd_progress module (#1035)."""
+import os
+import sys
+
+import pytest
+
+# Add lib to path
+_hooks_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+_lib_dir = os.path.join(_hooks_dir, "lib")
+if _lib_dir not in sys.path:
+    sys.path.insert(0, _lib_dir)
+
+from tdd_progress import build_tdd_indicator
+
+
+class TestBuildTddIndicator:
+    """Test build_tdd_indicator function."""
+
+    def test_red_phase(self):
+        result = build_tdd_indicator("RED")
+        assert result == "[RED \u25cf GREEN \u25cb REFACTOR \u25cb]"
+
+    def test_green_phase(self):
+        result = build_tdd_indicator("GREEN")
+        assert result == "[RED \u25cf GREEN \u25cf REFACTOR \u25cb]"
+
+    def test_refactor_phase(self):
+        result = build_tdd_indicator("REFACTOR")
+        assert result == "[RED \u25cf GREEN \u25cf REFACTOR \u25cf]"
+
+    def test_none_returns_none(self):
+        assert build_tdd_indicator(None) is None
+
+    def test_empty_string_returns_none(self):
+        assert build_tdd_indicator("") is None
+
+    def test_invalid_phase_returns_none(self):
+        assert build_tdd_indicator("INVALID") is None
+
+    def test_lowercase_phase(self):
+        result = build_tdd_indicator("red")
+        assert result == "[RED \u25cf GREEN \u25cb REFACTOR \u25cb]"
+
+    def test_mixed_case_phase(self):
+        result = build_tdd_indicator("Green")
+        assert result == "[RED \u25cf GREEN \u25cf REFACTOR \u25cb]"
+
+    def test_whitespace_trimmed(self):
+        result = build_tdd_indicator("  RED  ")
+        assert result == "[RED \u25cf GREEN \u25cb REFACTOR \u25cb]"
+
+
+class TestBuildTddIndicatorFromEnv:
+    """Test build_tdd_indicator reads from environment when no arg given."""
+
+    def test_reads_env_var(self, monkeypatch):
+        monkeypatch.setenv("CODINGBUDDY_TDD_PHASE", "GREEN")
+        result = build_tdd_indicator()
+        assert result == "[RED \u25cf GREEN \u25cf REFACTOR \u25cb]"
+
+    def test_no_env_var_returns_none(self, monkeypatch):
+        monkeypatch.delenv("CODINGBUDDY_TDD_PHASE", raising=False)
+        assert build_tdd_indicator() is None
+
+    def test_empty_env_var_returns_none(self, monkeypatch):
+        monkeypatch.setenv("CODINGBUDDY_TDD_PHASE", "")
+        assert build_tdd_indicator() is None
+
+
+class TestBuildTddIndicatorWithCycleCount:
+    """Test TDD indicator with cycle count display."""
+
+    def test_red_with_cycle_count(self):
+        result = build_tdd_indicator("RED", cycle_count=3)
+        assert result == "[RED \u25cf GREEN \u25cb REFACTOR \u25cb] #3"
+
+    def test_green_with_cycle_count(self):
+        result = build_tdd_indicator("GREEN", cycle_count=1)
+        assert result == "[RED \u25cf GREEN \u25cf REFACTOR \u25cb] #1"
+
+    def test_zero_cycle_count_omitted(self):
+        result = build_tdd_indicator("RED", cycle_count=0)
+        assert result == "[RED \u25cf GREEN \u25cb REFACTOR \u25cb]"
+
+    def test_none_cycle_count_omitted(self):
+        result = build_tdd_indicator("RED", cycle_count=None)
+        assert result == "[RED \u25cf GREEN \u25cb REFACTOR \u25cb]"