Ensure optional dev-dependencies are written to extras.

poetry/poetry.py

@@ -163,7 +163,7 @@ def create(cls, cwd):  # type: (Path) -> Poetry
             for req in requirements:
                 req = Dependency(req, "*")
 
-                for dep in package.requires:
+                for dep in package.all_requires:
                     if dep.name == req.name:
                         dep.in_extras.append(extra_name)
                         package.extras[extra_name].append(dep)

tests/fixtures/project_with_extras/pyproject.toml

@@ -13,5 +13,7 @@ cachy = { version = ">=0.2.0", optional = true }
 [tool.poetry.extras]
 extras_a = [ "pendulum" ]
 extras_b = [ "cachy" ]
+extras_c = [ "black" ]
 
 [tool.poetry.dev-dependencies]
+black = { version = "18.9b0", optional = true }

tests/test_poetry.py

@@ -156,3 +156,21 @@ def test_check_fails():
         )
 
     assert Poetry.check(content) == {"errors": [expected], "warnings": []}
+
+
+def test_poetry_writes_extras_from_dev_dependencies():
+    poetry = Poetry.create(str(fixtures_dir / "project_with_extras"))
+
+    package = poetry.package
+
+    dev_dependencies = {}
+    for dep in package.dev_requires:
+        dev_dependencies[dep.name] = dep
+
+    black = dev_dependencies["black"]
+    assert black.is_optional()
+
+    assert "extras_c" in package.extras
+    extras_c = package.extras["extras_c"]
+    assert len(extras_c) == 1
+    assert extras_c[0].name == "black"