fix: preserve user settings when enabling/disabling hooks

docs/BUG_FIX_CONFIG_PRESERVATION.md

@@ -0,0 +1,191 @@
+# Bug Fix: Config Preservation
+
+## Summary
+
+Critical bug fix: `cn off` was destroying all user settings in `settings.json` instead of only removing notification hooks.
+
+## The Problem
+
+### Before Fix (Bug Behavior)
+
+When users run `cn off` to disable notifications, the original code **overwrites the entire settings file**:
+
+```bash
+# User's original ~/.claude/settings.json
+{
+  "model": "sonnet",
+  "permissions": {
+    "allow": ["Bash(npm run*)", "Bash(pytest*)"]
+  },
+  "env": {
+    "MY_API_KEY": "secret-key"
+  }
+}
+
+# After running `cn off` (BUGGY!)
+{
+  "model": "opus"   # ← ALL OTHER SETTINGS DESTROYED!
+}
+```
+
+### Root Causes
+
+Three functions had this bug:
+
+| Function | File | Bug |
+|----------|------|-----|
+| `enable_hooks_in_settings()` | config.sh:233 | Hardcoded `"model": "opus"`, overwriting user's preference |
+| `disable_hooks_in_settings()` | config.sh:298 | Rewrote entire file to `{"model": "opus"}` or `{}` |
+| `disable_gemini_hooks()` | config.sh:588 | Rewrote entire file to `{"tools": {"enableHooks": false}}` |
+
+### Impact
+
+Users lost:
+- Their preferred model setting (e.g., `sonnet` → `opus`)
+- All permission rules
+- All environment variables
+- Any other custom settings
+
+## The Fix
+
+### After Fix (Correct Behavior)
+
+Now `cn off` only removes the `hooks` section while preserving all other settings:
+
+```bash
+# User's original ~/.claude/settings.json
+{
+  "model": "sonnet",
+  "permissions": {
+    "allow": ["Bash(npm run*)", "Bash(pytest*)"]
+  },
+  "env": {
+    "MY_API_KEY": "secret-key"
+  }
+}
+
+# After running `cn on` (adds hooks, preserves settings)
+{
+  "model": "sonnet",                    # ← PRESERVED
+  "permissions": {                      # ← PRESERVED
+    "allow": ["Bash(npm run*)", "Bash(pytest*)"]
+  },
+  "env": {                              # ← PRESERVED
+    "MY_API_KEY": "secret-key"
+  },
+  "hooks": {                            # ← ADDED
+    "Notification": [...],
+    "Stop": [...]
+  }
+}
+
+# After running `cn off` (removes hooks, preserves settings)
+{
+  "model": "sonnet",                    # ← STILL PRESERVED
+  "permissions": {                      # ← STILL PRESERVED
+    "allow": ["Bash(npm run*)", "Bash(pytest*)"]
+  },
+  "env": {                              # ← STILL PRESERVED
+    "MY_API_KEY": "secret-key"
+  }
+}
+```
+
+## Technical Changes
+
+### 1. `enable_hooks_in_settings()`
+
+**Before:**
+```bash
+# Hardcoded "opus" model
+echo '{"model": "opus", "hooks": {...}}' > "$GLOBAL_SETTINGS_FILE"
+```
+
+**After:**
+```bash
+# Use jq to merge hooks into existing settings
+jq '.hooks = {...}' existing_settings.json > "$GLOBAL_SETTINGS_FILE"
+```
+
+### 2. `disable_hooks_in_settings()`
+
+**Before:**
+```bash
+# Overwrote entire file
+echo '{"model": "opus"}' > "$GLOBAL_SETTINGS_FILE"
+```
+
+**After:**
+```bash
+# Only remove hooks key
+jq 'del(.hooks)' settings.json > "$GLOBAL_SETTINGS_FILE"
+```
+
+### 3. `disable_gemini_hooks()`
+
+**Before:**
+```bash
+# Overwrote entire file
+echo '{"tools": {"enableHooks": false}}' > "$GEMINI_SETTINGS_FILE"
+```
+
+**After:**
+```bash
+# Only remove code-notify hooks
+jq 'del(.hooks.Notification) | del(.hooks.AfterAgent)' settings.json
+```
+
+### Fallback Support
+
+For systems without `jq`, the fix uses `python3` as a fallback (available on most systems):
+
+```bash
+if has_jq; then
+    jq 'del(.hooks)' "$file"
+elif command -v python3 &> /dev/null; then
+    python3 -c "import json; ..."
+else
+    # Warn user, don't modify file (safer)
+    echo "Warning: jq or python3 required"
+fi
+```
+
+## Testing
+
+Added `tests/test-config-preservation.sh` that verifies:
+
+| Test | Description | Result |
+|------|-------------|--------|
+| Test 1 | `enable_hooks` preserves existing model | ✅ PASS |
+| Test 2 | `disable_hooks` preserves other settings | ✅ PASS |
+| Test 3 | Works with no existing config | ✅ PASS |
+
+Run tests:
+```bash
+./tests/test-config-preservation.sh
+```
+
+## Files Changed
+
+| File | Changes |
+|------|---------|
+| `lib/code-notify/core/config.sh` | Fixed 3 functions to preserve user settings |
+| `tests/test-config-preservation.sh` | New test file |
+
+## Migration Notes
+
+- No user action required
+- Existing configurations will be preserved correctly going forward
+- If you previously lost settings, you may need to reconfigure manually
+
+## Recommendation
+
+We strongly recommend installing `jq` for the best experience:
+```bash
+# macOS
+brew install jq
+
+# Linux
+sudo apt install jq  # Debian/Ubuntu
+sudo dnf install jq  # Fedora
+```

lib/code-notify/commands/global.sh

@@ -127,7 +127,10 @@ enable_single_tool() {
         info "Enabling $tool notifications..."
     fi
 
-    enable_tool "$tool"
+    if ! enable_tool "$tool"; then
+        error "Failed to enable $tool notifications"
+        return 1
+    fi
 
     local config_file
     case "$tool" in
@@ -197,7 +200,10 @@ disable_single_tool() {
         info "Disabling $tool notifications..."
     fi
 
-    disable_tool "$tool"
+    if ! disable_tool "$tool"; then
+        error "Failed to disable $tool notifications"
+        return 1
+    fi
 
     success "$tool: DISABLED"
     return 0