BUG: fix running a script with explicitly empty dependencies = [] (#1658)

* TST: add regression tests for running a script with implicitly or explicitly empty dependencies

* BUG: fix running a script with explicitly empty `dependencies = []`

Author: neutrinoceros

changelog.d/1658.bugfix.md

@@ -0,0 +1 @@
+Fix running a script with explicitly empty ``dependencies = []``.

src/pipx/commands/run.py

@@ -80,7 +80,7 @@ def run_script(
     use_cache: bool,
 ) -> NoReturn:
     requirements = _get_requirements_from_script(content)
-    if requirements is None:
+    if not requirements:
         python_path = Path(python)
     else:
         # Note that the environment name is based on the identified

tests/test_run.py

@@ -193,29 +193,58 @@ def test_run_without_requirements(caplog, pipx_temp_env, tmp_path):
 
 
 @mock.patch("os.execvpe", new=execvpe_mock)
-def test_run_with_requirements(caplog, pipx_temp_env, tmp_path):
+@pytest.mark.parametrize(
+    "script_text, expected_output",
+    [
+        pytest.param(
+            """
+            # /// script
+            # dependencies = []
+            # ///
+            from pathlib import Path
+            Path({out!r}).write_text("explicit-empty")
+            """,
+            "explicit-empty",
+            id="explicit-empty-dependencies",
+        ),
+        pytest.param(
+            """
+            # /// script
+            # ///
+            from pathlib import Path
+            Path({out!r}).write_text("implicit-empty")
+            """,
+            "implicit-empty",
+            id="implicit-empty-dependencies",
+        ),
+        pytest.param(
+            """
+            # /// script
+            # dependencies = ["requests==2.31.0"]
+            # ///
+
+            # Check requests can be imported
+            import requests
+            # Check dependencies of requests can be imported
+            import certifi
+            # Check the installed version
+            from pathlib import Path
+            Path({out!r}).write_text(requests.__version__)
+            """,
+            "2.31.0",
+            id="non-empty-dependencies",
+        ),
+    ],
+)
+def test_run_with_requirements(script_text, expected_output, caplog, pipx_temp_env, tmp_path):
     script = tmp_path / "test.py"
     out = tmp_path / "output.txt"
     script.write_text(
-        textwrap.dedent(
-            f"""
-                # /// script
-                # dependencies = ["requests==2.31.0"]
-                # ///
-
-                # Check requests can be imported
-                import requests
-                # Check dependencies of requests can be imported
-                import certifi
-                # Check the installed version
-                from pathlib import Path
-                Path({str(out)!r}).write_text(requests.__version__)
-            """
-        ).strip(),
+        textwrap.dedent(script_text.format(out=str(out))).strip(),
         encoding="utf-8",
     )
     run_pipx_cli_exit(["run", script.as_uri()])
-    assert out.read_text() == "2.31.0"
+    assert out.read_text() == expected_output
 
 
 @mock.patch("os.execvpe", new=execvpe_mock)