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.

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 = "moduleA", from = "libA" },
+    { include = "moduleB", from = "libB" },
+]
+
+[tool.poetry.dependencies]
+python = "^3.6"

tests/masonry/builders/test_sdist.py

@@ -629,3 +629,23 @@ 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 "moduleA" in ns["package_dir"] or "moduleB" in ns["package_dir"]
+    if "moduleA" in ns["package_dir"]:
+        assert ns["package_dir"]["moduleA"] == "libA/moduleA"
+    if "moduleB" in ns["package_dir"]:
+        assert ns["package_dir"]["moduleB"] == "libB/moduleB"