refactor(config): remove the notion of config layer incremental prepend/append.

Many moons gone past the original config system tried to support the idea
of incrementally stacked values (x y -x z -y == z).  This commit removes
the fundamental core of that functionality; the incremental logic is now implemented
in domain specific layers, rather than being a capability of the config layer.

Note: this just removes the logic.  The signature of [before, mid, after] return
is still in place, and will be removed as the API is normalized.  In particular,
pconfig still reports on .prepend/.apend, there just no longer is content there.

That behaviour (and signature) change will be a followon commit.

Signed-off-by: Brian Harring <ferringb@gmail.com>
Signed-off-by: Arthur Zamarin <arthurzam@gentoo.org>

3 files changed, 2 insertions, 170 deletions

diff --git a/tests/config/test_basics.py b/tests/config/test_basics.py
index e04cc704..10f0841e 100644
--- a/tests/config/test_basics.py
+++ b/tests/config/test_basics.py
@@ -248,87 +248,6 @@ class TestDictConfigSection:
             section.render_value(None, "list", "spoon")
 
 
-class TestFakeIncrementalDictConfigSection:
-    @staticmethod
-    def _convert(central, value, arg_type):
-        return central, value, arg_type
-
-    @staticmethod
-    def _fail(central, value, arg_type):
-        raise errors.ConfigurationError("fail")
-
-    def test_misc(self):
-        section = basics.FakeIncrementalDictConfigSection(
-            self._convert, {"list": [1, 2]}
-        )
-        assert "foo" not in section
-        assert "list" in section
-        assert ["list"] == list(section.keys())
-        with pytest.raises(errors.ConfigurationError):
-            obj = basics.FakeIncrementalDictConfigSection(self._fail, {"a": "b"})
-            obj.render_value(None, "a", "str")
-
-    def test_fake_incrementals(self):
-        section = basics.FakeIncrementalDictConfigSection(
-            self._convert, {"seq.append": [1, 2]}
-        )
-        manager = object()
-        assert [None, None, (manager, [1, 2], "list")] == section.render_value(
-            manager, "seq", "list"
-        )
-
-        def _repr(central, value, arg_type):
-            return "list", ["thing"]
-
-        section = basics.FakeIncrementalDictConfigSection(_repr, {"foo": None})
-        assert ("list", (None, ["thing"], None)) == section.render_value(
-            manager, "foo", "repr"
-        )
-        with pytest.raises(errors.ConfigurationError):
-            obj = basics.FakeIncrementalDictConfigSection(
-                self._fail, {"a.prepend": "b"}
-            )
-            obj.render_value(None, "a", "list")
-
-    def test_repr(self):
-        def asis(central, value, arg_type):
-            assert arg_type == "repr", arg_type
-            return value
-
-        source_dict = {
-            "seq.append": ("list", [1, 2]),
-            "simple": ("bool", True),
-            "multistr": ("str", "body"),
-            "multistr.prepend": ("str", "head"),
-            "refs": ("str", "lost"),
-            "refs.append": ("ref", "main"),
-            "refs.prepend": ("refs", ["a", "b"]),
-            "strlist": ("callable", asis),
-            "strlist.prepend": ("str", "whatever"),
-            "wrong.prepend": ("wrong", "wrong"),
-        }
-        section = basics.FakeIncrementalDictConfigSection(asis, source_dict)
-        manager = object()
-        with pytest.raises(KeyError):
-            section.render_value(manager, "spoon", "repr")
-        assert ("list", [None, None, [1, 2]]) == section.render_value(
-            manager, "seq", "repr"
-        )
-        assert ("bool", True) == section.render_value(manager, "simple", "repr")
-        assert ("str", ["head", "body", None]) == section.render_value(
-            manager, "multistr", "repr"
-        )
-        assert ("refs", [["a", "b"], ["lost"], ["main"]]) == section.render_value(
-            manager, "refs", "repr"
-        )
-        assert (
-            "list",
-            [["whatever"], ["tests.config.test_basics.asis"], None],
-        ) == section.render_value(manager, "strlist", "repr")
-        with pytest.raises(errors.ConfigurationError):
-            section.render_value(manager, "wrong", "repr")
-
-
 class TestConvertString:
     def test_render_value(self):
         source = {
diff --git a/tests/config/test_central.py b/tests/config/test_central.py
index 5ffb8072..55b541f8 100644
--- a/tests/config/test_central.py
+++ b/tests/config/test_central.py
@@ -970,89 +970,3 @@ def test_self_inherit():
     )
     assert manager.collapse_named_section("self")
     assert manager.collapse_section([section])
-
-
-def test_prepend_inherit():
-    manager = central.ConfigManager(
-        [{"sect": basics.HardCodedConfigSection({"inherit.prepend": ["self"]})}]
-    )
-    check_error(
-        "Collapsing section named 'sect':\n"
-        "Prepending or appending to the inherit list makes no sense",
-        manager.collapse_named_section,
-        "sect",
-    )
-
-
-def test_list_prepend():
-    @configurable(types={"seq": "list"})
-    def seq(seq):
-        return seq
-
-    manager = central.ConfigManager(
-        [
-            {
-                "inh": basics.HardCodedConfigSection(
-                    {
-                        "inherit": ["sect"],
-                        "seq.prepend": ["pre"],
-                    }
-                ),
-                "sect": basics.HardCodedConfigSection(
-                    {
-                        "inherit": ["base"],
-                        "seq": ["1", "2"],
-                    }
-                ),
-            },
-            {
-                "base": basics.HardCodedConfigSection(
-                    {
-                        "class": seq,
-                        "seq.prepend": ["-1"],
-                        "seq.append": ["post"],
-                    }
-                )
-            },
-        ]
-    )
-    assert ["-1", "post"] == manager.objects.seq["base"]
-    assert ["1", "2"] == manager.objects.seq["sect"]
-    assert ["pre", "1", "2"] == manager.objects.seq["inh"]
-
-
-def test_str_prepend():
-    @configurable(types={"string": "str"})
-    def sect(string):
-        return string
-
-    manager = central.ConfigManager(
-        [
-            {
-                "inh": basics.HardCodedConfigSection(
-                    {
-                        "inherit": ["sect"],
-                        "string.prepend": "pre",
-                    }
-                ),
-                "sect": basics.HardCodedConfigSection(
-                    {
-                        "inherit": ["base"],
-                        "string": "b",
-                    }
-                ),
-            },
-            {
-                "base": basics.HardCodedConfigSection(
-                    {
-                        "class": sect,
-                        "string.prepend": "a",
-                        "string.append": "c",
-                    }
-                )
-            },
-        ]
-    )
-    assert "a c" == manager.objects.sect["base"]
-    assert "b" == manager.objects.sect["sect"]
-    assert "pre b" == manager.objects.sect["inh"]
diff --git a/tests/config/test_cparser.py b/tests/config/test_cparser.py
index e7d0b0ea..a9082adb 100644
--- a/tests/config/test_cparser.py
+++ b/tests/config/test_cparser.py
@@ -2,6 +2,7 @@ import textwrap
 from io import StringIO
 
 import pytest
+
 from pkgcore.config import central, cparser, errors
 
 
@@ -33,8 +34,6 @@ class TestConfigFromIni:
             [test]
             string = 'hi I am a string'
             list = foo bar baz
-            list.prepend = pre bits
-            list.append = post bits
             true = yes
             false = no
         """
@@ -48,7 +47,7 @@ class TestConfigFromIni:
             (
                 "list",
                 "list",
-                [["pre", "bits"], ["foo", "bar", "baz"], ["post", "bits"]],
+                [None, ["foo", "bar", "baz"], None],
             ),
             ("true", "bool", True),
             ("false", "bool", False),