EAPI: add functionality for handling PMS eapis

This adds eapi.get_PMS_eapis? functionality which is intended
to simplify any tooling requiring PMS EAPIs to have that access.

While doing this, add a test_fixture to protect against bleed
through from test_eapi, and wire the ebd/Makefile to defer to
pkgcore rather than having it's own list of EAPIs.

Signed-off-by: Brian Harring <ferringb@gmail.com>

Author: ferringb

data/lib/pkgcore/ebd/Makefile

@@ -3,10 +3,14 @@ PYTHONPATH ?= ../../../../src
 PYTHON_CALL = PYTHONPATH="$(PYTHONPATH)" PYTHONDONTWRITEBYTECODE=1 $(PYTHON)
 
 TARGET = .generated
-KNOWN_EAPI = 0 1 2 3 4 5 6 7 8
+KNOWN_EAPI = $(shell $(PYTHON_CALL) -c 'from pkgcore.ebuild.eapi import EAPI; print(" ".join(EAPI.known_eapis))')
 
 all: funcs cmds libs
 
+.PHONY: eapis
+eapis:
+	@echo $(KNOWN_EAPI)
+
 clean:
 	$(RM) -r $(TARGET)
 

src/pkgcore/ebuild/eapi.py

@@ -12,6 +12,8 @@
 from snakeoil.osutils import pjoin
 from snakeoil.process.spawn import bash_version
 
+from typing import Iterable
+
 LATEST_PMS_EAPI_VER = "8"
 
 
@@ -155,6 +157,7 @@ def __init__(
         archive_exts=(),
         optionals=None,
         ebd_env_options=None,
+        pms=False,
     ):
         sf = object.__setattr__
 
@@ -194,6 +197,7 @@ def __init__(
         if ebd_env_options is None:
             ebd_env_options = ()
         sf(self, "_ebd_env_options", ebd_env_options)
+        sf(self, "pms", pms)
 
     @classmethod
     def register(cls, *args, **kwds):
@@ -479,8 +483,13 @@ def is_valid_use_flag(self, s: str) -> bool:
         return _valid_use_flag.match(s) is not None
 
 
-def get_eapi(magic, suppress_unsupported=True):
-    """Return EAPI object for a given identifier."""
+def get_eapi(magic, suppress_unsupported=True) -> None | EAPI:
+    """Return EAPI object for a given identifier.
+
+    If given suppress_unsupported, generate a fake EAPI and return that.
+    Use sparingly, this implicitly means pkgcore doesn't know the rules
+    for that metadata- so it's likely going to be wrong.
+    """
     if _valid_EAPI_regex.match(magic) is None:
         eapi_str = f" {magic!r}" if magic else ""
         raise ValueError(f"invalid EAPI{eapi_str}")
@@ -490,9 +499,21 @@ def get_eapi(magic, suppress_unsupported=True):
         if eapi is None:
             eapi = EAPI(magic=magic, optionals={"is_supported": False})
             EAPI.unknown_eapis[eapi._magic] = eapi
+
     return eapi
 
 
+def get_PMS_eapi(magic) -> None | EAPI:
+    """If a PMS EAPI is supported, return it."""
+    eapi = get_eapi(magic, suppress_unsupported=False)
+    return eapi if eapi.pms else None
+
+
+def get_PMS_eapis() -> Iterable[EAPI]:
+    """Returns all known EAPIs that are defined by PMS"""
+    return (eapi for eapi in EAPI.known_eapis.values() if eapi.pms)
+
+
 def _shorten_phase_name(func_name):
     if func_name.startswith(("src_", "pkg_")):
         return func_name[4:]
@@ -633,6 +654,7 @@ def _combine_dicts(*mappings):
     archive_exts=common_archive_exts,
     optionals=eapi_optionals,
     ebd_env_options=common_env_optionals,
+    pms=True,
 )
 
 eapi1 = EAPI.register(
@@ -654,6 +676,7 @@ def _combine_dicts(*mappings):
         ),
     ),
     ebd_env_options=eapi0._ebd_env_options,
+    pms=True,
 )
 
 eapi2 = EAPI.register(
@@ -682,6 +705,7 @@ def _combine_dicts(*mappings):
         ),
     ),
     ebd_env_options=eapi1._ebd_env_options,
+    pms=True,
 )
 
 eapi3 = EAPI.register(
@@ -702,6 +726,7 @@ def _combine_dicts(*mappings):
         ),
     ),
     ebd_env_options=eapi2._ebd_env_options,
+    pms=True,
 )
 
 eapi4 = EAPI.register(
@@ -731,6 +756,7 @@ def _combine_dicts(*mappings):
         ),
     ),
     ebd_env_options=eapi3._ebd_env_options,
+    pms=True,
 )
 
 eapi5 = EAPI.register(
@@ -757,6 +783,7 @@ def _combine_dicts(*mappings):
         ),
     ),
     ebd_env_options=eapi4._ebd_env_options,
+    pms=True,
 )
 
 eapi6 = EAPI.register(
@@ -782,6 +809,7 @@ def _combine_dicts(*mappings):
         ),
     ),
     ebd_env_options=eapi5._ebd_env_options,
+    pms=True,
 )
 
 eapi7 = EAPI.register(
@@ -810,6 +838,7 @@ def _combine_dicts(*mappings):
         ),
     ),
     ebd_env_options=eapi6._ebd_env_options,
+    pms=True,
 )
 
 eapi8 = EAPI.register(
@@ -846,4 +875,5 @@ def _combine_dicts(*mappings):
         ),
     ),
     ebd_env_options=eapi7._ebd_env_options,
+    pms=True,
 )

tests/ebuild/test_eapi.py

@@ -4,7 +4,35 @@
 import pytest
 from pkgcore.const import EBD_PATH
 from pkgcore.ebuild import eapi
-from pkgcore.ebuild.eapi import EAPI, eapi6, get_eapi
+from pkgcore.ebuild.eapi import EAPI, get_eapi
+
+
+# Seperate these so we can test the fixture implementation.
+def _protect_eapi_registration():
+    """Protect EAPI.known_eapi so any test manipulations can't persist"""
+    prior = EAPI.known_eapis.copy()
+    yield
+    EAPI.known_eapis.clear()
+    EAPI.known_eapis.update(prior)
+
+
+protect_eapi_registration = pytest.fixture(scope="function", autouse=True)(
+    _protect_eapi_registration
+)
+
+
+def test_eapi_registry_fixture():
+    prior = set(list(EAPI.known_eapis))
+    fixture = _protect_eapi_registration()
+    # start the fixture
+    next(fixture)
+    assert prior == set(EAPI.known_eapis), EAPI.known_eapis
+    # known_eapis is a weakval dict, thus we have to hold the reference
+    _x = EAPI.register("foon")
+    assert len(EAPI.known_eapis) - 1 == len(prior)
+    # finish the fixture via exausting the iterator
+    list(fixture)
+    assert set(EAPI.known_eapis) == prior
 
 
 def test_get_eapi():
@@ -15,21 +43,59 @@ def test_get_eapi():
     assert unknown_eapi == get_eapi("unknown")
 
     # known EAPI
-    eapi = get_eapi("6")
-    assert eapi6 == eapi
+    assert get_eapi("6") == eapi.eapi6
+
+
+def test_get_PMS_eapi():
+    # test PMS filtration
+    assert get_eapi("6") is eapi.eapi6
+    # hold the reference, known_eapis is weakval
+    temp = EAPI.register("1234")
+    # confirm it's visable
+    assert get_eapi("1234", suppress_unsupported=False) is temp
+    assert eapi.get_PMS_eapi("1234") is None
+    temp2 = EAPI.register("9999", pms=True)
+    assert eapi.get_PMS_eapi("9999") is temp2
+
+
+def test_get_PMS_eapis():
+    pms_eapis = set(eapi.get_PMS_eapis())
+    expected = set(x for x in EAPI.known_eapis.values() if x.pms)
+    assert pms_eapis == expected
+
+
+def test_get_latest_pms_eapi():
+    # if it's not in there, the magic constant isn't in alignment
+    assert eapi.get_latest_PMS_eapi() in list(eapi.get_PMS_eapis())
+
+    # Note, this can false positive while a new  EAPI is being developed.  If this
+    # is an actual issue, then introduce a flag on EAPI objects that indicates 'latest pms',
+    # and update get_latest_PMS_eapi to scan for that, and register() to block duplicate.
+    assert (
+        eapi.get_latest_PMS_eapi()
+        is sorted(
+            (x for x in EAPI.known_eapis.values() if x.pms),
+            key=lambda e: int(e._magic),
+            reverse=True,
+        )[0]
+    )
 
 
 class TestEAPI:
+    def test_pms_default_off(self):
+        assert EAPI("asdf").pms == False
+        assert EAPI.register("asdf").pms == False
+
     def test_register(self, tmp_path):
         # re-register known EAPI
         with pytest.raises(ValueError):
             EAPI.register(magic="0")
 
         mock_ebd_temp = str(shutil.copytree(EBD_PATH, tmp_path / "ebd"))
-        with mock.patch(
-            "pkgcore.ebuild.eapi.bash_version"
-        ) as bash_version, mock.patch.dict(eapi.EAPI.known_eapis), mock.patch(
-            "pkgcore.ebuild.eapi.const.EBD_PATH", mock_ebd_temp
+        with (
+            mock.patch("pkgcore.ebuild.eapi.bash_version") as bash_version,
+            mock.patch.dict(eapi.EAPI.known_eapis),
+            mock.patch("pkgcore.ebuild.eapi.const.EBD_PATH", mock_ebd_temp),
         ):
             # inadequate bash version
             bash_version.return_value = "3.1"
@@ -49,11 +115,12 @@ def test_register(self, tmp_path):
             assert test_eapi._magic == "test1"
 
     def test_is_supported(self, tmp_path, caplog):
-        assert eapi6.is_supported
+        assert eapi.eapi6.is_supported
 
         mock_ebd_temp = str(shutil.copytree(EBD_PATH, tmp_path / "ebd"))
-        with mock.patch.dict(eapi.EAPI.known_eapis), mock.patch(
-            "pkgcore.ebuild.eapi.const.EBD_PATH", mock_ebd_temp
+        with (
+            mock.patch.dict(eapi.EAPI.known_eapis),
+            mock.patch("pkgcore.ebuild.eapi.const.EBD_PATH", mock_ebd_temp),
         ):
             # partially supported EAPI is flagged as such
             test_eapi = EAPI.register("test", optionals={"is_supported": False})