feat: Expose installed binaries under PATH for custom packages

src/isolate/connections/_local/_base.py

@@ -28,6 +28,28 @@
 ConnectionType = TypeVar("ConnectionType")
 
 
+def binary_path_for(*search_paths: Path) -> str:
+    """Return the binary search path for the given 'search_paths'.
+    It will be a combination of the 'bin/' folders in them and
+    the existing PATH environment variable."""
+
+    paths = []
+    for search_path in search_paths:
+        path = sysconfig.get_path("scripts", vars={"base": search_path})
+        paths.append(path)
+        # Some distributions (conda) might include both a 'bin' and
+        # a 'scripts' folder.
+
+        auxilary_binary_path = search_path / "bin"
+        if path != auxilary_binary_path and auxilary_binary_path.exists():
+            paths.append(str(auxilary_binary_path))
+
+    if "PATH" in os.environ:
+        paths.append(os.environ["PATH"])
+
+    return os.pathsep.join(paths)
+
+
 def python_path_for(*search_paths: Path) -> str:
     """Return the PYTHONPATH for the library paths residing
     in the given 'search_paths'. The order of the paths is
@@ -98,13 +120,22 @@ def get_env_vars(self) -> Dict[str, str]:
         custom_vars = {}
         custom_vars[AGENT_SIGNATURE] = "1"
         custom_vars["PYTHONUNBUFFERED"] = "1"
+
+        # NOTE: we don't have to manually set PYTHONPATH here if we are
+        # using a single environment since python will automatically
+        # use the proper path.
         if self.extra_inheritance_paths:
             # The order here should reflect the order of the inheritance
             # where the actual environment already takes precedence.
-            python_path = python_path_for(
+            custom_vars["PYTHONPATH"] = python_path_for(
                 self.environment_path, *self.extra_inheritance_paths
             )
-            custom_vars["PYTHONPATH"] = python_path
+
+        # But the PATH must be always set since it will be not be
+        # automatically set by Python (think of this as ./venv/bin/activate)
+        custom_vars["PATH"] = binary_path_for(
+            self.environment_path, *self.extra_inheritance_paths
+        )
 
         return {
             **os.environ,

src/isolate/server/server.py

@@ -102,7 +102,7 @@ def Run(
                 future = local_pool.submit(
                     _proxy_to_queue,
                     queue=messages,
-                    connection=connection,
+                    connection=cast(LocalPythonGRPC, connection),
                     input=request.function,
                 )
 

tests/test_backends.py

@@ -134,6 +134,17 @@ def test_invalid_project_building(self, tmp_path, monkeypatch):
 
         assert not environment.exists()
 
+    @pytest.mark.parametrize("executable", ["python"])
+    def test_path_resolution(self, tmp_path, executable):
+        import shutil
+
+        environment = self.get_project_environment(tmp_path, "example-binary")
+        environment_path = environment.create()
+        with environment.open_connection(environment_path) as connection:
+            executable_path = Path(connection.run(partial(shutil.which, executable)))
+            assert executable_path.exists()
+            assert executable_path.relative_to(environment_path)
+
 
 class TestVirtualenv(GenericEnvironmentTests):
 
@@ -151,6 +162,9 @@ class TestVirtualenv(GenericEnvironmentTests):
         "invalid-project": {
             "requirements": ["pyjokes==999.999.999"],
         },
+        "example-binary": {
+            "requirements": [],
+        },
     }
     creation_entry_point = ("virtualenv.cli_run", PermissionError)
 
@@ -246,6 +260,9 @@ class TestConda(GenericEnvironmentTests):
         "r": {
             "packages": ["r-base=4.2.2"],
         },
+        "example-binary": {
+            "packages": ["python"],
+        },
     }
     creation_entry_point = ("subprocess.check_call", subprocess.SubprocessError)
 
@@ -283,6 +300,14 @@ def test_local_python_environment():
         local_env.destroy(connection_key)
 
 
+def test_path_on_local():
+    import shutil
+
+    local_env = LocalPythonEnvironment()
+    with local_env.connect() as connection:
+        assert connection.run(partial(shutil.which, "python")) == shutil.which("python")
+
+
 def test_isolate_server_environment(isolate_server):
     environment = IsolateServer(
         host=isolate_server,