Reuse locked package info for vcs/file/url deps

Prior to this change, when add/remove/lock commands were executed,
poetry would re-inspect all locked vcs/file/url dependencies. This is
sub-optimal and not required. This change enables reuse of locked
package info.

poetry/installation/installer.py

@@ -178,7 +178,7 @@ def _do_install(self, local_repo):
 
         locked_repository = Repository()
         if self._update:
-            if self._locker.is_locked() and not self._lock:
+            if self._locker.is_locked():
                 locked_repository = self._locker.locked_repository(True)
 
                 # If no packages have been whitelisted (The ones we want to update),

poetry/puzzle/provider.py

@@ -31,6 +31,7 @@
 from poetry.packages.package_collection import PackageCollection
 from poetry.puzzle.exceptions import OverrideNeeded
 from poetry.repositories import Pool
+from poetry.repositories import Repository
 from poetry.utils._compat import OrderedDict
 from poetry.utils._compat import Path
 from poetry.utils._compat import urlparse
@@ -55,8 +56,8 @@ class Provider:
     UNSAFE_PACKAGES = {"setuptools", "distribute", "pip"}
 
     def __init__(
-        self, package, pool, io, env=None
-    ):  # type: (Package, Pool, Any, Optional[Env]) -> None
+        self, package, pool, io, env=None, locked=None
+    ):  # type: (Package, Pool, Any, Optional[Env], Optional[Repository]) -> None
         self._package = package
         self._pool = pool
         self._io = io
@@ -67,6 +68,11 @@ def __init__(
         self._in_progress = False
         self._overrides = {}
         self._deferred_cache = {}
+        self._locked_packages = {}
+
+        if locked:
+            for package in locked.packages:
+                self._locked_packages[package.name] = package
 
     @property
     def pool(self):  # type: () -> Pool
@@ -164,6 +170,9 @@ def search_for_vcs(self, dependency):  # type: (VCSDependency) -> List[Package]
         if dependency in self._deferred_cache:
             return [self._deferred_cache[dependency]]
 
+        if dependency.name in self._locked_packages:
+            return [self._locked_packages[dependency.name]]
+
         package = self.get_package_from_vcs(
             dependency.vcs,
             dependency.source,
@@ -223,6 +232,8 @@ def search_for_file(self, dependency):  # type: (FileDependency) -> List[Package
             dependency, _package = self._deferred_cache[dependency]
 
             package = _package.clone()
+        elif dependency.name in self._locked_packages:
+            package = self._locked_packages[dependency.name].clone()
         else:
             package = self.get_package_from_file(dependency.full_path)
 
@@ -279,6 +290,8 @@ def search_for_directory(
             dependency, _package = self._deferred_cache[dependency]
 
             package = _package.clone()
+        elif dependency.name in self._locked_packages:
+            package = self._locked_packages[dependency.name].clone()
         else:
             package = self.get_package_from_directory(
                 dependency.full_path, name=dependency.name
@@ -329,6 +342,9 @@ def search_for_url(self, dependency):  # type: (URLDependency) -> List[Package]
         if dependency in self._deferred_cache:
             return [self._deferred_cache[dependency]]
 
+        if dependency.name in self._locked_packages:
+            return [self._locked_packages[dependency.name]]
+
         package = self.get_package_from_url(dependency.url)
 
         if dependency.name != package.name:

poetry/puzzle/solver.py

@@ -44,7 +44,9 @@ def __init__(
         self._io = io
 
         if provider is None:
-            provider = Provider(self._package, self._pool, self._io)
+            provider = Provider(
+                self._package, self._pool, self._io, locked=self._locked
+            )
 
         self._provider = provider
         self._overrides = []

tests/installation/test_installer.py

@@ -11,6 +11,7 @@
 from poetry.installation.executor import Executor as BaseExecutor
 from poetry.installation.noop_installer import NoopInstaller
 from poetry.packages import Locker as BaseLocker
+from poetry.puzzle.provider import Provider
 from poetry.repositories import Pool
 from poetry.repositories import Repository
 from poetry.repositories.installed_repository import InstalledRepository
@@ -27,7 +28,7 @@
 from tests.repositories.test_pypi_repository import MockRepository
 
 
-fixtures_dir = Path("tests/fixtures")
+fixtures_dir = Path(__file__).parent.parent / "fixtures"
 
 
 class Installer(BaseInstaller):
@@ -1757,3 +1758,67 @@ def test_installer_can_handle_old_lock_files(
 
     # colorama will be added
     assert 8 == installer.executor.installations_count
+
+
+def installer_add_with_existing_demo_package(
+    package, locker, repo, installer, lock_data, demo_constraint
+):
+    locker.locked(True)
+    locker.mock_lock_data(lock_data)
+
+    repo.add_package(get_package("A", "1.0"))
+
+    package.add_dependency("demo", demo_constraint)
+    package.add_dependency("A", "^1.0")
+
+    installer.update(True)
+    installer.run()
+
+
+def test_installer_reuse_lock_data_file(mocker, installer, locker, repo, package):
+    spy = mocker.spy(Provider, "get_package_from_file")
+    data = fixture("with-reusable-package-info-git")
+    constraint = {
+        "file": str(fixtures_dir / "distributions/demo-0.1.0-py2.py3-none-any.whl")
+    }
+    installer_add_with_existing_demo_package(
+        package=package,
+        locker=locker,
+        repo=repo,
+        installer=installer,
+        lock_data=data,
+        demo_constraint=constraint,
+    )
+    spy.assert_not_called()
+
+
+def test_installer_reuse_lock_data_git(mocker, installer, locker, repo, package):
+    spy = mocker.spy(Provider, "get_package_from_vcs")
+    data = fixture("with-reusable-package-info-git")
+    constraint = {"git": "https://github.com/demo/demo.git"}
+    installer_add_with_existing_demo_package(
+        package=package,
+        locker=locker,
+        repo=repo,
+        installer=installer,
+        lock_data=data,
+        demo_constraint=constraint,
+    )
+    spy.assert_not_called()
+
+
+def test_installer_reuse_lock_data_url(mocker, installer, locker, repo, package):
+    spy = mocker.spy(Provider, "get_package_from_url")
+    data = fixture("with-reusable-package-info-url")
+    constraint = {
+        "url": "https://python-poetry.org/distributions/demo-0.1.0-py2.py3-none-any.whl"
+    }
+    installer_add_with_existing_demo_package(
+        package=package,
+        locker=locker,
+        repo=repo,
+        installer=installer,
+        lock_data=data,
+        demo_constraint=constraint,
+    )
+    spy.assert_not_called()