Merge pull request #7979 from uranusjr/editable

Implement editable candidate

src/pip/_internal/resolution/resolvelib/candidates.py

@@ -5,7 +5,10 @@ from pip._vendor.packaging.specifiers import InvalidSpecifier, SpecifierSet
 from pip._vendor.packaging.utils import canonicalize_name
 from pip._vendor.packaging.version import Version
 
-from pip._internal.req.constructors import install_req_from_line
+from pip._internal.req.constructors import (
+    install_req_from_editable,
+    install_req_from_line,
+)
 from pip._internal.req.req_install import InstallRequirement
 from pip._internal.utils.misc import normalize_version_info
 from pip._internal.utils.packaging import get_requires_python
@@ -25,13 +28,19 @@ if MYPY_CHECK_RUNNING:
     from .base import Requirement
     from .factory import Factory
 
+    BaseCandidate = Union[
+        "AlreadyInstalledCandidate",
+        "EditableCandidate",
+        "LinkCandidate",
+    ]
+
 
 logger = logging.getLogger(__name__)
 
 
 def make_install_req_from_link(link, parent):
     # type: (Link, InstallRequirement) -> InstallRequirement
-    # TODO: Do we need to support editables?
+    assert not parent.editable, "parent is editable"
     return install_req_from_line(
         link.url,
         comes_from=parent.comes_from,
@@ -46,9 +55,28 @@ def make_install_req_from_link(link, parent):
     )
 
 
+def make_install_req_from_editable(link, parent):
+    # type: (Link, InstallRequirement) -> InstallRequirement
+    assert parent.editable, "parent not editable"
+    return install_req_from_editable(
+        link.url,
+        # HACK: install_req_from_editable accepts Optional[str] here, but
+        # parent.comes_from is Union[str, InstallRequirement, None]. How do
+        # we fix the type hint conflicts?
+        comes_from=parent.comes_from,  # type: ignore
+        use_pep517=parent.use_pep517,
+        isolated=parent.isolated,
+        constraint=parent.constraint,
+        options=dict(
+            install_options=parent.install_options,
+            global_options=parent.global_options,
+            hashes=parent.hash_options
+        ),
+    )
+
+
 def make_install_req_from_dist(dist, parent):
     # type: (Distribution, InstallRequirement) -> InstallRequirement
-    # TODO: Do we need to support editables?
     ireq = install_req_from_line(
         "{}=={}".format(
             canonicalize_name(dist.project_name),
@@ -192,6 +220,29 @@ class LinkCandidate(_InstallRequirementBackedCandidate):
         return self._factory.preparer.prepare_linked_requirement(self._ireq)
 
 
+class EditableCandidate(_InstallRequirementBackedCandidate):
+    def __init__(
+        self,
+        link,          # type: Link
+        parent,        # type: InstallRequirement
+        factory,       # type: Factory
+        name=None,     # type: Optional[str]
+        version=None,  # type: Optional[_BaseVersion]
+    ):
+        # type: (...) -> None
+        super(EditableCandidate, self).__init__(
+            link=link,
+            ireq=make_install_req_from_editable(link, parent),
+            factory=factory,
+            name=name,
+            version=version,
+        )
+
+    def _get_abstract_distribution(self):
+        # type: () -> AbstractDistribution
+        return self._factory.preparer.prepare_editable_requirement(self._ireq)
+
+
 class AlreadyInstalledCandidate(Candidate):
     def __init__(
         self,
@@ -259,7 +310,7 @@ class ExtrasCandidate(Candidate):
     """
     def __init__(
         self,
-        base,  # type: Union[AlreadyInstalledCandidate, LinkCandidate]
+        base,  # type: BaseCandidate
         extras,  # type: Set[str]
     ):
         # type: (...) -> None

src/pip/_internal/resolution/resolvelib/factory.py

@@ -8,6 +8,7 @@ from pip._internal.utils.typing import MYPY_CHECK_RUNNING
 
 from .candidates import (
     AlreadyInstalledCandidate,
+    EditableCandidate,
     ExtrasCandidate,
     LinkCandidate,
     RequiresPythonCandidate,
@@ -33,6 +34,7 @@ if MYPY_CHECK_RUNNING:
     from pip._internal.resolution.base import InstallRequirementProvider
 
     from .base import Candidate, Requirement
+    from .candidates import BaseCandidate
 
     C = TypeVar("C")
     Cache = Dict[Link, C]
@@ -56,6 +58,7 @@ class Factory(object):
         self._ignore_installed = ignore_installed
         self._ignore_requires_python = ignore_requires_python
         self._link_candidate_cache = {}  # type: Cache[LinkCandidate]
+        self._editable_candidate_cache = {}  # type: Cache[EditableCandidate]
 
     def _make_candidate_from_dist(
         self,
@@ -78,11 +81,18 @@ class Factory(object):
         version=None,  # type: Optional[_BaseVersion]
     ):
         # type: (...) -> Candidate
-        if link not in self._link_candidate_cache:
-            self._link_candidate_cache[link] = LinkCandidate(
-                link, parent, factory=self, name=name, version=version,
-            )
-        base = self._link_candidate_cache[link]
+        if parent.editable:
+            if link not in self._editable_candidate_cache:
+                self._editable_candidate_cache[link] = EditableCandidate(
+                    link, parent, factory=self, name=name, version=version,
+                )
+            base = self._editable_candidate_cache[link]  # type: BaseCandidate
+        else:
+            if link not in self._link_candidate_cache:
+                self._link_candidate_cache[link] = LinkCandidate(
+                    link, parent, factory=self, name=name, version=version,
+                )
+            base = self._link_candidate_cache[link]
         if extras:
             return ExtrasCandidate(base, extras)
         return base

tests/functional/test_new_resolver.py

@@ -1,10 +1,12 @@
 import json
+import os
 
 import pytest
 
 from tests.lib import (
     create_basic_sdist_for_package,
     create_basic_wheel_for_package,
+    create_test_package_with_setup,
 )
 
 
@@ -27,6 +29,15 @@ def assert_not_installed(script, *args):
         "{!r} contained in {!r}".format(args, installed)
 
 
+def assert_editable(script, *args):
+    # This simply checks whether all of the listed packages have a
+    # corresponding .egg-link file installed.
+    # TODO: Implement a more rigorous way to test for editable installations.
+    egg_links = set("{}.egg-link".format(arg) for arg in args)
+    assert egg_links <= set(os.listdir(script.site_packages_path)), \
+        "{!r} not all found in {!r}".format(args, script.site_packages_path)
+
+
 def test_new_resolver_can_install(script):
     create_basic_wheel_for_package(
         script,
@@ -144,6 +155,29 @@ def test_new_resolver_installs_extras(script):
     assert_installed(script, base="0.1.0", dep="0.1.0")
 
 
+def test_new_resolver_installs_editable(script):
+    create_basic_wheel_for_package(
+        script,
+        "base",
+        "0.1.0",
+        depends=["dep"],
+    )
+    source_dir = create_test_package_with_setup(
+        script,
+        name="dep",
+        version="0.1.0",
+    )
+    script.pip(
+        "install", "--unstable-feature=resolver",
+        "--no-cache-dir", "--no-index",
+        "--find-links", script.scratch_path,
+        "base",
+        "--editable", source_dir,
+    )
+    assert_installed(script, base="0.1.0", dep="0.1.0")
+    assert_editable(script, "dep")
+
+
 @pytest.mark.parametrize(
     "requires_python, ignore_requires_python, dep_version",
     [