Incorporate two special actions: info and uninstall.

pyempaq/unpacker.py

@@ -35,6 +35,9 @@
 # so it's easily patchable by tests
 MAGIC_NUMBER = importlib.util.MAGIC_NUMBER[:-2].hex()
 
+# the environment variable to specify a different action
+ACTION_ENVVAR = "PYEMPAQ_ACTION"
+
 # setup logging
 logger = logging.getLogger()
 handler = logging.StreamHandler()
@@ -58,12 +61,49 @@ class ReturnCode(enum.IntEnum):
         restrictions_not_met = 64
         unpack_basedir_missing = 65
         unpack_basedir_notdir = 66
+        bad_action = 67
 
     def __init__(self, code):
         self.returncode = code
         super().__init__("")
 
 
+# -- special PyEmpaq actions
+
+def special_action_info(pyempaq_dir, metadata):
+    """Provide information about different installations for the project."""
+    print("Base PyEmpaq directory:", pyempaq_dir)
+    subdirs = sorted(pyempaq_dir.glob(f"{metadata['project_name']}-*"))
+    if not subdirs:
+        print("No installation found!")
+        return
+
+    print("Current installations:")
+    for subdir in subdirs:
+        print("   ", subdir.name)
+
+
+def special_action_uninstall(pyempaq_dir, metadata):
+    """Remove all installations for the given project."""
+    subdirs = list(pyempaq_dir.glob(f"{metadata['project_name']}-*"))
+    if not subdirs:
+        print("No installation found!")
+        return
+
+    print("Removing installation:")
+    for subdir in subdirs:
+        print("   ", subdir.name)
+        shutil.rmtree(subdir)
+
+
+ACTION_CHOICES = {
+    "info": special_action_info,
+    "uninstall": special_action_uninstall,
+}
+
+# --
+
+
 def get_python_exec(project_dir: pathlib.Path) -> pathlib.Path:
     """Return the Python exec to use.
 
@@ -265,6 +305,19 @@ def run():
     pyempaq_dir = get_base_dir(platformdirs)
     logger.info("Base directory: %r", str(pyempaq_dir))
 
+    indicated_action = os.environ.get(ACTION_ENVVAR)
+    if indicated_action is not None:
+        indicated_action = indicated_action.lower()
+        print(f"Running {indicated_action!r} action")
+        try:
+            func = ACTION_CHOICES[indicated_action]
+        except KeyError:
+            logger.error(
+                "Bad specified action %s=%r; valid options: %s",
+                ACTION_ENVVAR, indicated_action, ", ".join(ACTION_CHOICES.keys()))
+            raise FatalError(FatalError.ReturnCode.bad_action)
+        return func(pyempaq_dir, metadata)
+
     # create a temp dir and extract the project there
     project_dir = pyempaq_dir / build_project_install_dir(pyempaq_filepath, metadata)
     original_project_dir = project_dir / "orig"

tests/test_integration.py

@@ -5,14 +5,15 @@
 """Integration tests."""
 
 import os
+import shutil
 import subprocess
 import sys
 import textwrap
 
 import pytest
 import yaml
 
-from pyempaq.unpacker import FatalError
+from pyempaq.unpacker import FatalError, ACTION_ENVVAR, get_file_hexdigest
 
 
 def _pack(tmp_path, monkeypatch, config_text):
@@ -40,8 +41,9 @@ def _unpack(packed_filepath, basedir, *, extra_env=None, expected_rc=None):
     """
     # run the packed file in a clean directory
     cleandir = basedir / "cleandir"
-    cleandir.mkdir()
-    new_path = packed_filepath.rename(cleandir / "testproject.pyz")
+    cleandir.mkdir(exist_ok=True)
+    new_path = cleandir / "testproject.pyz"
+    shutil.copy(packed_filepath, new_path)
     os.chdir(cleandir)
 
     # set the install basedir so the user real one is not used, and then any extra
@@ -276,3 +278,73 @@ def test_using_entrypoint(tmp_path, monkeypatch):
 
     assert proc.returncode == 0
     assert proc.stdout.strip() == "crazyarg"
+
+
+# -- check special actions
+
+
+def test_action_info(tmp_path, monkeypatch):
+    """Use the special action 'info'."""
+    # set up a basic test project, with an entrypoint that shows access to internals
+    projectpath = tmp_path / "fakeproject"
+    entrypoint = projectpath / "ep.py"
+    entrypoint.parent.mkdir()
+    entrypoint.write_text("print(42)")
+
+    packed_filepath = _pack(tmp_path, monkeypatch, f"""
+        name: testproject
+        basedir: {projectpath}
+        exec:
+          script: ep.py
+    """)
+
+    # unpack it once so it's already installed
+    proc, run_path = _unpack(packed_filepath, tmp_path, expected_rc=0)
+    assert proc.returncode == 0
+
+    # run the action
+    extra_env = {ACTION_ENVVAR: "info"}
+    proc, run_path = _unpack(packed_filepath, tmp_path, expected_rc=0, extra_env=extra_env)
+    assert proc.returncode == 0
+
+    hexdigest = get_file_hexdigest(packed_filepath)
+    assert proc.stdout == textwrap.dedent(f"""\
+        Running 'info' action
+        Base PyEmpaq directory: {tmp_path}
+        Current installations:
+            testproject-{hexdigest[:20]}-cpython.3.10.6f0d
+    """)
+
+
+def test_action_uninstall(tmp_path, monkeypatch):
+    """Use the special action 'uninstall'."""
+    # set up a basic test project, with an entrypoint that shows access to internals
+    projectpath = tmp_path / "fakeproject"
+    entrypoint = projectpath / "ep.py"
+    entrypoint.parent.mkdir()
+    entrypoint.write_text("print(42)")
+
+    packed_filepath = _pack(tmp_path, monkeypatch, f"""
+        name: testproject
+        basedir: {projectpath}
+        exec:
+          script: ep.py
+    """)
+
+    # unpack it once so it's already installed
+    proc, run_path = _unpack(packed_filepath, tmp_path, expected_rc=0)
+    assert proc.returncode == 0
+    assert len(list(tmp_path.glob("testproject-*"))) == 1
+
+    # run the action
+    extra_env = {ACTION_ENVVAR: "uninstall"}
+    proc, run_path = _unpack(packed_filepath, tmp_path, expected_rc=0, extra_env=extra_env)
+    assert proc.returncode == 0
+    assert len(list(tmp_path.glob("testproject-*"))) == 0
+
+    hexdigest = get_file_hexdigest(packed_filepath)
+    assert proc.stdout == textwrap.dedent(f"""\
+        Running 'uninstall' action
+        Removing installation:
+            testproject-{hexdigest[:20]}-cpython.3.10.6f0d
+    """)

tests/test_unpacker.py

@@ -8,6 +8,7 @@
 import json
 import os
 import platform
+import textwrap
 import time
 import zipfile
 from pathlib import Path
@@ -28,6 +29,8 @@
     get_base_dir,
     run_command,
     setup_project_directory,
+    special_action_info,
+    special_action_uninstall,
 )
 
 
@@ -399,3 +402,60 @@ def test_installdirname_custombase_not_dir(monkeypatch, tmp_path):
     with pytest.raises(FatalError) as cm:
         get_base_dir(platformdirs)
     assert cm.value.returncode is FatalError.ReturnCode.unpack_basedir_notdir
+
+
+# --- tests for the special actions
+
+
+def test_specialaction_info_simple(tmp_path, capsys):
+    """A couple of installs to show."""
+    (tmp_path / "testproj-whatever-123").mkdir()
+    (tmp_path / "testproj-another one").mkdir()
+    special_action_info(tmp_path, {"project_name": "testproj"})
+
+    out, _ = capsys.readouterr()
+    assert out == textwrap.dedent(f"""\
+        Base PyEmpaq directory: {tmp_path}
+        Current installations:
+            testproj-another one
+            testproj-whatever-123
+    """)
+
+
+def test_specialaction_info_nothing(tmp_path, capsys):
+    """No install to show information."""
+    special_action_info(tmp_path, {"project_name": "testproj"})
+
+    out, _ = capsys.readouterr()
+    assert out == textwrap.dedent(f"""\
+        Base PyEmpaq directory: {tmp_path}
+        No installation found!
+    """)
+
+
+def test_specialaction_uninstall_simple(tmp_path, capsys):
+    """Some installs to remove."""
+    inst1 = tmp_path / "testproj-whatever-123"
+    inst1.mkdir()
+    inst2 = tmp_path / "testproj-another one"
+    inst2.mkdir()
+    special_action_uninstall(tmp_path, {"project_name": "testproj"})
+
+    out, _ = capsys.readouterr()
+    assert out == textwrap.dedent("""\
+        Removing installation:
+            testproj-another one
+            testproj-whatever-123
+    """)
+    assert not inst1.exists()
+    assert not inst2.exists()
+
+
+def test_specialaction_uninstall_nothing(tmp_path, capsys):
+    """No install to remove."""
+    special_action_uninstall(tmp_path, {"project_name": "testproj"})
+
+    out, _ = capsys.readouterr()
+    assert out == textwrap.dedent("""\
+        No installation found!
+    """)