feat(#24,#25): --dry-run for collect + enhanced --dry-run for sync with file paths

src/collect.py

@@ -64,11 +64,17 @@ def _resolve_memory_conflicts(
     help="Comma-separated list of tools to collect from (e.g., claude,cursor)",
 )
 @click.option("--no-memory", is_flag=True, help="Skip collecting memory entries")
+@click.option(
+    "--dry-run",
+    is_flag=True,
+    help="Show what would be collected without writing to cache. (#25)",
+)
 @click.option("--yes", "-y", is_flag=True, help="Skip confirmation prompt")
-def collect(tools, no_memory, yes):
+def collect(tools, no_memory, dry_run, yes):
     """Extract from installed AI tools and save to local cache.
 
     No login or network required.
+    Use --dry-run to preview what would be collected without writing.
     """
     # --- Phase 1: Scan ---
     header("Scanning")
@@ -163,6 +169,35 @@ def collect(tools, no_memory, yes):
         store_secrets_batch("local", all_secrets)
         success(f"Stored {len(all_secrets)} secret(s) in OS keychain")
 
+    # --- Dry-run: preview without writing (#25) ---
+    if dry_run:
+        from cache import get_cache_dir
+
+        cache_dir = get_cache_dir()
+        info("\n[dry-run] Would write to cache:")
+        info(f"  {cache_dir / 'skills.json'}   ({len(new_skills)} skills)")
+        info(f"  {cache_dir / 'mcp.json'}       ({len(new_mcp_servers)} MCP servers)")
+        info(f"  {cache_dir / 'memory.json'}    ({len(selected_memory)} memory entries)")
+
+        if new_skills:
+            info("\n  Skills:")
+            for s in new_skills:
+                info(f"    • {s.get('name', '?')}  ({s.get('source_tool', '')})")
+
+        if new_mcp_servers:
+            info("\n  MCP Servers:")
+            for sv in new_mcp_servers:
+                info(f"    • {sv.get('name', '?')}  ({sv.get('source_tool', '')})")
+
+        if selected_memory:
+            info("\n  Memory files:")
+            for e in selected_memory:
+                label = e.get("label") or e.get("source_file") or e.get("content", "")[:40]
+                info(f"    • {e.get('source_tool', '?')}/{label}")
+
+        info("\n[dry-run] No files written.")
+        return
+
     # Merge into existing cache (upsert, never delete)
     merged_skills = merge_skills(load_skills(), new_skills)
     merged_mcp = merge_mcp_servers(load_mcp_servers(), new_mcp_servers)

src/main.py

@@ -121,7 +121,40 @@ def sync(tools, apply_all, no_memory, override_mcp, dry_run, yes):
         info(f"Skills: {len(collected_skills)} collected + {installed_count} installed")
 
     if dry_run:
-        info("[dry-run] No files written.")
+        # Show the file paths that would be written for each target tool (#24)
+        from appliers import get_applier
+
+        info("\n[dry-run] Files that would be written:")
+        for tool_name in tool_list:
+            try:
+                applier = get_applier(tool_name)
+                info(f"\n  [{tool_name}]")
+                # Skills
+                if collected_skills or installed_count:
+                    if hasattr(applier, "SKILL_DIR") and applier.SKILL_DIR:
+                        info(f"    Skills dir: {applier.SKILL_DIR}")
+                # MCP config
+                for attr in ("_mcp_config", "_mcp_config_path"):
+                    fn = getattr(type(applier), attr, None) or getattr(applier, attr, None)
+                    if callable(fn):
+                        try:
+                            info(f"    MCP config: {fn()}")
+                        except Exception:
+                            pass
+                # Memory target
+                mem_target = getattr(applier, "MEMORY_TARGET_FILE", None)
+                if callable(mem_target):
+                    mem_target = mem_target  # property — access below
+                try:
+                    mf = applier.MEMORY_TARGET_FILE
+                    if mf:
+                        info(f"    Memory:     {mf}")
+                except Exception:
+                    pass
+            except Exception as e:
+                info(f"  [{tool_name}] (could not inspect: {e})")
+
+        info("\n[dry-run] No files written.")
         return
 
     # Confirm

tests/test_docker_integration.py

@@ -1449,3 +1449,99 @@ def test_status_after_round_trip(self, runner, cli, export_path):
 
         r = runner.invoke(cli, ["status"])
         assert r.exit_code == 0
+
+
+# ---------------------------------------------------------------------------
+# Phase 12: --dry-run for collect (#25) and sync (#24)
+# ---------------------------------------------------------------------------
+
+
+class TestCollectDryRun:
+    """End-to-end: collect --dry-run previews without writing cache."""
+
+    def test_collect_dry_run_no_files_written(self, runner, cli, tmp_path, monkeypatch):
+        """collect --dry-run must not create any cache files."""
+        monkeypatch.setenv("HOME", str(tmp_path))
+        (tmp_path / ".cursor").mkdir()
+        (tmp_path / ".cursor" / "mcp.json").write_text("{}")
+
+        result = runner.invoke(cli, ["collect", "--dry-run", "--yes"])
+        assert result.exit_code == 0, result.output
+
+        cache_dir = tmp_path / ".apc" / "cache"
+        for fname in ("skills.json", "mcp.json", "memory.json"):
+            assert not (cache_dir / fname).exists(), f"{fname} written despite --dry-run"
+
+    def test_collect_dry_run_prints_preview(self, runner, cli, tmp_path, monkeypatch):
+        """collect --dry-run output shows 'Would write to cache' preview."""
+        monkeypatch.setenv("HOME", str(tmp_path))
+        (tmp_path / ".cursor").mkdir()
+        (tmp_path / ".cursor" / "mcp.json").write_text(
+            json.dumps({"mcpServers": {"test": {"command": "npx", "args": []}}})
+        )
+
+        result = runner.invoke(cli, ["collect", "--dry-run", "--yes"])
+        assert result.exit_code == 0, result.output
+        # Output says "Would write to cache:" or "No files written."
+        out = result.output.lower()
+        assert "write to cache" in out or "no files written" in out
+
+    def test_collect_without_dry_run_writes_cache(self, runner, cli, tmp_path, monkeypatch):
+        """Control: without --dry-run the cache IS written."""
+        monkeypatch.setenv("HOME", str(tmp_path))
+        (tmp_path / ".cursor").mkdir()
+        (tmp_path / ".cursor" / "mcp.json").write_text(
+            json.dumps({"mcpServers": {"test-mcp": {"command": "npx", "args": []}}})
+        )
+
+        result = runner.invoke(cli, ["collect", "--yes"])
+        assert result.exit_code == 0, result.output
+
+        # At least one cache file must have been written
+        cache_dir = tmp_path / ".apc" / "cache"
+        cache_files = ("skills.json", "mcp.json", "memory.json")
+        written = [f for f in cache_files if (cache_dir / f).exists()]
+        assert written, f"No cache files written without --dry-run. Output:\n{result.output}"
+
+
+class TestSyncDryRunIntegration:
+    """End-to-end: sync --dry-run previews without modifying tool files."""
+
+    def test_sync_dry_run_no_files_written(self, runner, cli, tmp_path, monkeypatch):
+        """sync --dry-run must not modify any tool config files."""
+        monkeypatch.setenv("HOME", str(tmp_path))
+        (tmp_path / ".cursor").mkdir()
+        mcp_path = tmp_path / ".cursor" / "mcp.json"
+        mcp_path.write_text(json.dumps({"mcpServers": {"test": {"command": "npx", "args": []}}}))
+
+        runner.invoke(cli, ["collect", "--yes"])
+
+        mtime_before = mcp_path.stat().st_mtime
+        result = runner.invoke(cli, ["sync", "--tools", "cursor", "--dry-run"])
+        assert result.exit_code == 0, result.output
+        assert mcp_path.stat().st_mtime == mtime_before, "sync --dry-run modified mcp.json"
+
+    def test_sync_dry_run_output_mentions_tool(self, runner, cli, tmp_path, monkeypatch):
+        """sync --dry-run output references the target tool."""
+        monkeypatch.setenv("HOME", str(tmp_path))
+        (tmp_path / ".cursor").mkdir()
+        (tmp_path / ".cursor" / "mcp.json").write_text(
+            json.dumps({"mcpServers": {"test": {"command": "npx", "args": []}}})
+        )
+
+        runner.invoke(cli, ["collect", "--yes"])
+        result = runner.invoke(cli, ["sync", "--tools", "cursor", "--dry-run"])
+        assert result.exit_code == 0, result.output
+        assert "cursor" in result.output or "dry-run" in result.output.lower()
+
+    def test_sync_dry_run_shows_no_files_written(self, runner, cli, tmp_path, monkeypatch):
+        """sync --dry-run explicitly states no files written."""
+        monkeypatch.setenv("HOME", str(tmp_path))
+        (tmp_path / ".cursor").mkdir()
+        (tmp_path / ".cursor" / "mcp.json").write_text(
+            json.dumps({"mcpServers": {"test": {"command": "npx", "args": []}}})
+        )
+
+        runner.invoke(cli, ["collect", "--yes"])
+        result = runner.invoke(cli, ["sync", "--tools", "cursor", "--dry-run"])
+        assert "No files written" in result.output or "dry-run" in result.output.lower()

tests/test_dry_run.py

@@ -0,0 +1,172 @@
+"""Tests for --dry-run on apc collect (#25) and apc sync (#24).
+
+apc collect --dry-run: previews what would be collected without writing.
+apc sync --dry-run:    previews file paths per tool without writing.
+"""
+
+import sys
+import unittest
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+sys.path.insert(0, str(Path(__file__).parent.parent / "src"))
+
+from click.testing import CliRunner
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+
+def _cli():
+    from main import cli
+
+    return cli
+
+
+def _runner():
+    return CliRunner()
+
+
+def _mock_extractor(skills=None, mcp=None, memory=None):
+    """Return a MagicMock extractor with canned data."""
+    ext = MagicMock()
+    ext.extract_skills.return_value = skills or []
+    ext.extract_mcp_servers.return_value = mcp or []
+    ext.extract_memory.return_value = memory or []
+    return ext
+
+
+# ---------------------------------------------------------------------------
+# apc collect --dry-run (#25)
+# ---------------------------------------------------------------------------
+
+
+class TestCollectDryRun(unittest.TestCase):
+    """collect --dry-run must preview without touching the cache."""
+
+    def _invoke(self, skills=None, mcp=None, memory=None, extra_args=None):
+        import tempfile
+
+        with tempfile.TemporaryDirectory() as td:
+            td = Path(td)
+            cache_dir = td / ".apc" / "cache"
+            extractor = _mock_extractor(
+                skills=skills or [{"name": "pdf", "source_tool": "claude-code", "body": "# PDF"}],
+                mcp=mcp
+                or [{"name": "test-mcp", "source_tool": "cursor", "command": "npx", "args": []}],
+                memory=memory or [],
+            )
+            args = ["collect", "--dry-run", "--yes"] + (extra_args or [])
+            with (
+                patch("collect.detect_installed_tools", return_value=["claude-code"]),
+                patch("collect.get_extractor", return_value=extractor),
+                patch("cache.get_cache_dir", return_value=cache_dir),
+            ):
+                result = _runner().invoke(_cli(), args)
+            return result, cache_dir
+
+    def test_dry_run_flag_accepted(self):
+        result, _ = self._invoke()
+        assert result.exit_code == 0, result.output
+
+    def test_dry_run_shows_cache_paths(self):
+        result, _ = self._invoke()
+        # Paths may wrap across lines in rich output; check for filename substrings
+        flat = result.output.replace("\n", " ")
+        assert "skills.j" in flat  # skills.json (may wrap)
+        assert "mcp.json" in flat
+        assert "memory.j" in flat  # memory.json (may wrap)
+
+    def test_dry_run_shows_skill_count(self):
+        result, _ = self._invoke(
+            skills=[
+                {"name": "pdf", "source_tool": "claude-code", "body": "# PDF"},
+                {"name": "sk", "source_tool": "claude-code", "body": "# SK"},
+            ]
+        )
+        assert "2 skills" in result.output
+
+    def test_dry_run_shows_mcp_count(self):
+        result, _ = self._invoke(
+            mcp=[
+                {"name": "mcp-a", "source_tool": "cursor", "command": "npx", "args": []},
+                {"name": "mcp-b", "source_tool": "cursor", "command": "npx", "args": []},
+                {"name": "mcp-c", "source_tool": "cursor", "command": "npx", "args": []},
+            ]
+        )
+        assert "3 MCP" in result.output
+
+    def test_dry_run_lists_skill_names(self):
+        result, _ = self._invoke(
+            skills=[{"name": "pdf", "source_tool": "claude-code", "body": "# PDF"}]
+        )
+        assert "pdf" in result.output
+
+    def test_dry_run_does_not_write_cache(self):
+        """Cache files must NOT be created when --dry-run is used."""
+        result, cache_dir = self._invoke()
+        assert result.exit_code == 0, result.output
+        assert not (cache_dir / "skills.json").exists(), "skills.json written in dry-run"
+        assert not (cache_dir / "mcp.json").exists(), "mcp.json written in dry-run"
+        assert not (cache_dir / "memory.json").exists(), "memory.json written in dry-run"
+
+    def test_dry_run_no_files_written_message(self):
+        result, _ = self._invoke(skills=[], mcp=[], memory=[])
+        assert "No files written" in result.output or "dry-run" in result.output.lower()
+
+    def test_dry_run_memory_entries_listed(self):
+        mem = [{"source_tool": "claude-code", "source_file": "CLAUDE.md", "content": "Some rule"}]
+        result, _ = self._invoke(memory=mem)
+        assert "claude-code" in result.output or "CLAUDE.md" in result.output
+
+
+# ---------------------------------------------------------------------------
+# apc sync --dry-run (#24)
+# ---------------------------------------------------------------------------
+
+
+class TestSyncDryRun(unittest.TestCase):
+    """sync --dry-run must preview file paths per tool without writing."""
+
+    def _invoke_sync_dry(self, tools="cursor"):
+        mock_bundle = {
+            "skills": [{"name": "pdf", "source_tool": "claude-code", "body": "# PDF"}],
+            "mcp_servers": [{"name": "test-mcp", "command": "npx", "args": []}],
+            "memory": [],
+        }
+        with (
+            patch("main.load_local_bundle", return_value=mock_bundle),
+            patch("main.count_installed_skills", return_value=1),
+            patch("main.resolve_target_tools", return_value=[tools]),
+        ):
+            return _runner().invoke(_cli(), ["sync", "--dry-run", "--yes"])
+
+    def test_dry_run_flag_accepted(self):
+        result = self._invoke_sync_dry()
+        assert result.exit_code == 0, result.output
+
+    def test_dry_run_shows_no_files_written(self):
+        result = self._invoke_sync_dry()
+        assert "No files written" in result.output or "dry-run" in result.output.lower()
+
+    def test_dry_run_shows_tool_name(self):
+        result = self._invoke_sync_dry(tools="cursor")
+        assert "cursor" in result.output
+
+    def test_dry_run_does_not_call_sync_all(self):
+        """sync_all must not be called in dry-run mode."""
+        mock_bundle = {
+            "skills": [{"name": "pdf", "source_tool": "claude-code", "body": "# PDF"}],
+            "mcp_servers": [],
+            "memory": [],
+        }
+        with (
+            patch("main.load_local_bundle", return_value=mock_bundle),
+            patch("main.count_installed_skills", return_value=1),
+            patch("main.resolve_target_tools", return_value=["cursor"]),
+            patch("main.sync_all") as mock_sync,
+        ):
+            _runner().invoke(_cli(), ["sync", "--dry-run", "--yes"])
+
+        mock_sync.assert_not_called()