Fix for including modules from different locations (python-poetry#108)

* Fix for including modules from different locations

When we define multiple packages from different source locations,
Poetry currently only uses the last specified from= location.
This patch adds explicit paths to package_dir for additional packages.

This fixes python-poetry#1811, fixes python-poetry#2354,
and possibly even python-poetry#2450.

* Test the fix for including modules from different locations

When we try to include moduleA from libA and moduleB from libB then
package_dir in the generated setup.py must to contain either one or
both `"moduleA": "libA/moduleA"` or `"moduleB": "libB/moduleB"`
so we are able to find both modules when building the source dist.

`ns["package_dir"].keys() == {"", "module_b"}`
should always be true, so we don't have to test for module_a in
`ns["package_dir"]`.

poetry/core/masonry/builders/sdist.py

@@ -139,7 +139,14 @@ def build_setup(self) -> bytes:
                     pkg_dir, _packages, _package_data = self.find_packages(include)
 
                     if pkg_dir is not None:
-                        package_dir[""] = os.path.relpath(pkg_dir, str(self._path))
+                        pkg_root = os.path.relpath(pkg_dir, str(self._path))
+                        if "" in package_dir:
+                            package_dir.update(
+                                (p, os.path.join(pkg_root, p.replace(".", "/")))
+                                for p in _packages
+                            )
+                        else:
+                            package_dir[""] = pkg_root
 
                     packages += [p for p in _packages if p not in packages]
                     package_data.update(_package_data)

tests/masonry/builders/fixtures/split_source/pyproject.toml

@@ -0,0 +1,15 @@
+[tool.poetry]
+name = "split-source"
+version = "0.1"
+description = "Combine packages from different locations."
+authors = [
+    "Jan Harkes <jaharkes@cs.cmu.edu>"
+]
+license = "MIT"
+packages = [
+    { include = "module_a", from = "lib_a" },
+    { include = "module_b", from = "lib_b" },
+]
+
+[tool.poetry.dependencies]
+python = "^3.6"

tests/masonry/builders/test_sdist.py

@@ -629,3 +629,19 @@ def test_sdist_mtime_zero():
     with gzip.open(str(sdist), "rb") as gz:
         gz.read(100)
         assert gz.mtime == 0
+
+
+def test_split_source():
+    root = fixtures_dir / "split_source"
+    poetry = Factory().create_poetry(root)
+
+    builder = SdistBuilder(poetry)
+
+    # Check setup.py
+    setup = builder.build_setup()
+    setup_ast = ast.parse(setup)
+
+    setup_ast.body = [n for n in setup_ast.body if isinstance(n, ast.Assign)]
+    ns = {}
+    exec(compile(setup_ast, filename="setup.py", mode="exec"), ns)
+    assert "" in ns["package_dir"] and "module_b" in ns["package_dir"]