Initial project structure for spice2wireviz

SPICE netlist to WireViz YAML converter with:
- Custom lightweight netlist parser (.net/.cir/.sp)
- Single-module mapper (subcircuit external interface)
- Inter-module mapper (multi-board wiring)
- Filter engine with glob patterns
- Click CLI with auto-detection, inspection commands
- Optional .asc parser via spicelib
- Comprehensive test suite with fixtures

tests/test_cli.py

@@ -0,0 +1,130 @@
+"""Tests for the Click CLI."""
+
+from pathlib import Path
+
+from click.testing import CliRunner
+
+from spice2wireviz.cli import main
+
+FIXTURES = Path(__file__).parent / "fixtures"
+
+
+class TestCLIBasic:
+    def test_version(self):
+        runner = CliRunner()
+        result = runner.invoke(main, ["--version"])
+        assert result.exit_code == 0
+        assert "2026-02-13" in result.output
+
+    def test_list_subcircuits(self):
+        runner = CliRunner()
+        result = runner.invoke(main, [str(FIXTURES / "multi_board.net"), "--list-subcircuits"])
+        assert result.exit_code == 0
+        assert "power_supply" in result.output
+        assert "amplifier" in result.output
+        assert "io_board" in result.output
+
+    def test_list_components(self):
+        runner = CliRunner()
+        result = runner.invoke(main, [str(FIXTURES / "multi_board.net"), "--list-components"])
+        assert result.exit_code == 0
+        assert "J_CHASSIS" in result.output
+        assert "TP_VCC" in result.output
+
+    def test_nonexistent_file(self):
+        runner = CliRunner()
+        result = runner.invoke(main, ["/nonexistent/file.net"])
+        assert result.exit_code != 0
+
+
+class TestCLISingleModule:
+    def test_single_mode_explicit(self):
+        runner = CliRunner()
+        result = runner.invoke(
+            main,
+            [str(FIXTURES / "simple_board.net"), "-m", "single", "-s", "amplifier_board"],
+        )
+        assert result.exit_code == 0
+        assert "connectors:" in result.output
+        assert "amplifier_board" in result.output
+
+    def test_single_mode_auto_detect(self):
+        runner = CliRunner()
+        result = runner.invoke(
+            main, [str(FIXTURES / "simple_board.net"), "-s", "amplifier_board"]
+        )
+        assert result.exit_code == 0
+        assert "connectors:" in result.output
+
+    def test_single_mode_only_subcircuit(self):
+        """When netlist has one subcircuit and no instances, auto-detect single mode."""
+        runner = CliRunner()
+        result = runner.invoke(main, [str(FIXTURES / "simple_board.net")])
+        assert result.exit_code == 0
+        assert "connectors:" in result.output
+
+    def test_dry_run(self):
+        runner = CliRunner()
+        result = runner.invoke(
+            main,
+            [str(FIXTURES / "simple_board.net"), "-s", "amplifier_board", "--dry-run"],
+        )
+        assert result.exit_code == 0
+        assert "Mode: single" in result.output
+        assert "Connectors:" in result.output
+
+
+class TestCLIInterModule:
+    def test_inter_mode_explicit(self):
+        runner = CliRunner()
+        result = runner.invoke(
+            main, [str(FIXTURES / "multi_board.net"), "-m", "inter"]
+        )
+        assert result.exit_code == 0
+        assert "connectors:" in result.output
+        assert "cables:" in result.output
+
+    def test_inter_mode_auto_detect(self):
+        runner = CliRunner()
+        result = runner.invoke(main, [str(FIXTURES / "multi_board.net")])
+        assert result.exit_code == 0
+        assert "connectors:" in result.output
+
+    def test_output_to_file(self, tmp_path):
+        out = tmp_path / "output.yml"
+        runner = CliRunner()
+        result = runner.invoke(
+            main, [str(FIXTURES / "multi_board.net"), "-o", str(out)]
+        )
+        assert result.exit_code == 0
+        assert out.exists()
+        content = out.read_text()
+        assert "connectors:" in content
+
+
+class TestCLIFiltering:
+    def test_no_ground(self):
+        runner = CliRunner()
+        result = runner.invoke(
+            main, [str(FIXTURES / "multi_board.net"), "--no-ground"]
+        )
+        assert result.exit_code == 0
+        # GND should not appear in pinlabels
+        assert "- GND" not in result.output
+
+    def test_include_prefixes(self):
+        runner = CliRunner()
+        result = runner.invoke(
+            main,
+            [str(FIXTURES / "multi_board.net"), "--include-prefixes", "J"],
+        )
+        assert result.exit_code == 0
+
+    def test_exclude_refs(self):
+        runner = CliRunner()
+        result = runner.invoke(
+            main,
+            [str(FIXTURES / "multi_board.net"), "--exclude-refs", "X1,TP_VCC"],
+        )
+        assert result.exit_code == 0
+        assert "X1:" not in result.output