Add subdirectory refs to pip installer

Co-authored-by: Randy Döring <30527984+radoering@users.noreply.github.com>

src/poetry/installation/pip_installer.py

@@ -183,6 +183,9 @@ class PipInstaller(BaseInstaller):
                 f"#egg={package.name}"
             )
 
+            if package.source_subdirectory:
+                req += f"&subdirectory={package.source_subdirectory}"
+
             if package.develop:
                 return ["-e", req]
 
@@ -217,6 +220,9 @@ class PipInstaller(BaseInstaller):
         else:
             req = Path(package.source_url).resolve(strict=False)
 
+        if package.source_subdirectory:
+            req /= package.source_subdirectory
+
         pyproject = PyProjectTOML(os.path.join(req, "pyproject.toml"))
 
         if pyproject.is_poetry_project():
@@ -278,9 +284,13 @@ class PipInstaller(BaseInstaller):
         )
 
         # Now we just need to install from the source directory
-        pkg = Package(package.name, package.version)
-        pkg._source_type = "directory"
-        pkg._source_url = str(source.path)
-        pkg.develop = package.develop
+        pkg = Package(
+            name=package.name,
+            version=package.version,
+            source_type="directory",
+            source_url=str(source.path),
+            source_subdirectory=package.source_subdirectory,
+            develop=package.develop,
+        )
 
         self.install_directory(pkg)

tests/installation/test_pip_installer.py

@@ -39,6 +39,20 @@ def package_git() -> Package:
 
 
 @pytest.fixture
+def package_git_with_subdirectory() -> Package:
+    package = Package(
+        "subdirectories",
+        "2.0.0",
+        source_type="git",
+        source_url="https://github.com/demo/subdirectories.git",
+        source_reference="master",
+        source_subdirectory="two",
+    )
+
+    return package
+
+
+@pytest.fixture
 def pool() -> Pool:
     return Pool()
 
@@ -85,6 +99,24 @@ def test_requirement_source_type_url():
     assert result == expected
 
 
+def test_requirement_git_subdirectory(
+    pool: Pool, package_git_with_subdirectory: Package
+) -> None:
+    null_env = NullEnv()
+    installer = PipInstaller(null_env, NullIO(), pool)
+    result = installer.requirement(package_git_with_subdirectory)
+    expected = (
+        "git+https://github.com/demo/subdirectories.git"
+        "@master#egg=subdirectories&subdirectory=two"
+    )
+
+    assert result == expected
+    installer.install(package_git_with_subdirectory)
+    assert len(null_env.executed) == 1
+    cmd = null_env.executed[0]
+    assert Path(cmd[-1]).parts[-3:] == ("demo", "subdirectories", "two")
+
+
 def test_requirement_git_develop_false(installer: PipInstaller, package_git: Package):
     package_git.develop = False
     result = installer.requirement(package_git)