Fix test failures that depend on the local machine

tests/test_adopt.py

@@ -354,8 +354,9 @@ def hello(name):
 
         # Run the generated tests with the source on PYTHONPATH
         import subprocess
+        import sys
         proc = subprocess.run(
-            ["python3", "-m", "pytest", str(test_file), "-v"],
+            [sys.executable, "-m", "pytest", str(test_file), "-v"],
             capture_output=True, text=True,
             cwd=str(tmp_path),
             env={**__import__("os").environ, "PYTHONPATH": str(tmp_path)},

tests/test_environment.py

@@ -1,5 +1,6 @@
 """Tests for EnvironmentSpec."""
 import os
+import sysconfig
 from pact.config import EnvironmentSpec, resolve_environment, GlobalConfig, ProjectConfig
 
 
@@ -48,10 +49,13 @@ def test_build_env_fallback_minimal_path(self):
         env = spec.build_env("src")
         assert "/usr/bin" in env["PATH"]
 
-    def test_validate_finds_pytest(self):
+    def test_validate_finds_pytest(self, monkeypatch):
+        # The pytest script sits beside this interpreter, which is only on PATH
+        # when the venv is activated (not under `.venv/bin/python -m pytest`).
+        scripts = sysconfig.get_path("scripts")
+        monkeypatch.setenv("PATH", scripts + os.pathsep + os.environ.get("PATH", ""))
         spec = EnvironmentSpec(required_tools=["pytest"])
         missing = spec.validate_environment()
-        # pytest should be installed in our test environment
         assert "pytest" not in missing
 
     def test_validate_finds_missing_tool(self):

tests/test_tool_index.py

@@ -3,6 +3,8 @@
 from __future__ import annotations
 
 import json
+import shutil
+import subprocess
 import textwrap
 from pathlib import Path
 from unittest.mock import MagicMock, patch
@@ -29,20 +31,52 @@
 )
 
 
+def _has_universal_ctags() -> bool:
+    # macOS ships BSD ctags at /usr/bin/ctags, which pact deliberately ignores.
+    try:
+        out = subprocess.run(["ctags", "--version"], capture_output=True, text=True).stdout
+    except OSError:
+        return False
+    return "Universal Ctags" in out
+
+
+def _has_tree_sitter_python() -> bool:
+    try:
+        import tree_sitter  # noqa: F401
+        import tree_sitter_python  # noqa: F401
+    except ImportError:
+        return False
+    return True
+
+
+requires_ctags = pytest.mark.skipif(
+    not _has_universal_ctags(), reason="universal-ctags not installed",
+)
+requires_cscope = pytest.mark.skipif(
+    shutil.which("cscope") is None, reason="cscope not installed",
+)
+requires_tree_sitter = pytest.mark.skipif(
+    not _has_tree_sitter_python(), reason="tree-sitter not installed (analysis extra)",
+)
+
+
 # ── Tool Detection ────────────────────────────────────────────────
 
 
 class TestDetectTools:
+    @requires_ctags
     def test_detects_ctags(self):
         avail = detect_tools()
         # ctags should be installed (universal-ctags via brew)
         assert avail.ctags is True
         assert avail.ctags_version != ""
 
+    @requires_cscope
     def test_detects_cscope(self):
         avail = detect_tools()
         assert avail.cscope is True
 
+    @requires_tree_sitter
     def test_detects_tree_sitter(self):
         avail = detect_tools()
         assert avail.tree_sitter is True
@@ -72,6 +106,7 @@ def test_run_quiet_missing_command(self):
 # ── ctags ─────────────────────────────────────────────────────────
 
 
+@requires_ctags
 class TestCtags:
     def test_run_ctags_on_sample(self, tmp_path):
         """ctags should find functions in a simple Python file."""
@@ -152,6 +187,7 @@ def test_cscope_empty_dir(self, tmp_path):
 
 
 class TestTreeSitter:
+    @requires_tree_sitter
     def test_run_tree_sitter_on_sample(self, tmp_path):
         """tree-sitter should extract function and class definitions."""
         (tmp_path / "sample.py").write_text(textwrap.dedent("""\
@@ -169,6 +205,7 @@ def greet(self, name: str) -> str:
         assert "Greeter" in names
         assert "greet" in names
 
+    @requires_tree_sitter
     def test_tree_sitter_symbol_metadata(self, tmp_path):
         (tmp_path / "funcs.py").write_text(textwrap.dedent("""\
             class Calculator:
@@ -184,6 +221,7 @@ def add(self, a, b):
         assert add_sym.parent == "Calculator"
         assert add_sym.parent_kind == "class"
 
+    @requires_tree_sitter
     def test_tree_sitter_class_definition(self, tmp_path):
         (tmp_path / "models.py").write_text("class User:\n    pass\n")
         symbols = run_tree_sitter(tmp_path, "python")
@@ -208,6 +246,7 @@ def test_tree_sitter_unsupported_language(self, tmp_path):
         symbols = run_tree_sitter(tmp_path, "definitely_not_supported")
         assert symbols == []
 
+    @requires_tree_sitter
     def test_tree_sitter_multiline_function(self, tmp_path):
         (tmp_path / "big.py").write_text(textwrap.dedent("""\
             def complex_function(
@@ -410,6 +449,8 @@ def test_cscope_handles_no_binary(self):
 
 
 class TestIntegration:
+    @requires_ctags
+    @requires_tree_sitter
     def test_build_tool_index_real(self, tmp_path):
         """Integration test: build_tool_index on a real (small) codebase."""
         (tmp_path / "app.py").write_text(textwrap.dedent("""\
@@ -430,6 +471,7 @@ def run(self):
         assert idx.total_symbols > 0
         assert idx.total_tree_sitter_symbols > 0
 
+    @requires_ctags
     def test_analyze_codebase_includes_tool_index(self, tmp_path):
         """analyze_codebase() should attach tool_index to the result."""
         (tmp_path / "main.py").write_text("def hello(): pass\n")