Fixes #1509 short-circuit of installing packages when already install…

…ed (#1510)

Co-authored-by: chrysle <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

changelog.d/1509.bugfix.md

@@ -0,0 +1 @@
+Fix installation abortion on multiple packages when one or more are already installed.

src/pipx/commands/install.py

@@ -84,7 +84,11 @@ def install(
                         """
                     )
                 )
-                return EXIT_CODE_INSTALL_VENV_EXISTS
+                if len(package_specs) == 1:
+                    return EXIT_CODE_INSTALL_VENV_EXISTS
+                # Reset venv_dir to None ready to install the next package in the list
+                venv_dir = None
+                continue
 
         try:
             # Enable installing shared library `pip` with `pipx`

tests/test_install.py

@@ -85,6 +85,19 @@ def test_install_tricky_packages(capsys, pipx_temp_env, caplog, package_name, pa
     install_packages(capsys, pipx_temp_env, caplog, [package_spec], [package_name])
 
 
+def test_install_multiple_packages_when_some_already_installed(capsys, pipx_temp_env, caplog):
+    run_pipx_cli(["install", "black", "pycowsay"])
+    captured = capsys.readouterr()
+    assert "installed package black" in captured.out
+    assert "installed package pycowsay" in captured.out
+
+    run_pipx_cli(["install", "black", "pycowsay", "isort"])
+    captured = capsys.readouterr()
+    assert "'black' already seems to be installed" in captured.out
+    assert "'pycowsay' already seems to be installed" in captured.out
+    assert "installed package isort" in captured.out
+
+
 def test_install_tricky_multiple_packages(capsys, pipx_temp_env, caplog):
     if os.getenv("FAST"):
         pytest.skip("skipping slow tests")