Separate test for checking black replaces config with linked one

tests/invalid_test.toml

@@ -1,9 +1,2 @@
 [tool.black]
 config = "tests/bazqux.toml"
-
-[v1.0.0-syntax]
-# This shouldn't break Black.
-contributors = [
-  "Foo Bar <foo@example.com>",
-  { name = "Baz Qux", email = "bazqux@example.com", url = "https://example.com/bazqux" }
-]

tests/test.toml

@@ -1,8 +1,12 @@
 [tool.black]
-config = "test_black.toml"
-verbose = 0
-color = false
+verbose = 1
+--check = "no"
+diff = "y"
+color = true
 line-length = 79
+target-version = ["py36", "py37", "py38"]
+exclude='\.pyi?$'
+include='\.py?$'
 
 [v1.0.0-syntax]
 # This shouldn't break Black.

tests/test_black.py

@@ -1268,10 +1268,14 @@ def test_invalid_config_return_code(self) -> None:
     def test_parse_pyproject_toml(self) -> None:
         test_toml_file = THIS_DIR / "test.toml"
         config = black.parse_pyproject_toml(str(test_toml_file))
-        self.assertEqual(config["verbose"], 0)
-        self.assertEqual(config["config"], "test_black.toml")
-        self.assertEqual(config["color"], False)
+        self.assertEqual(config["verbose"], 1)
+        self.assertEqual(config["check"], "no")
+        self.assertEqual(config["diff"], "y")
+        self.assertEqual(config["color"], True)
         self.assertEqual(config["line_length"], 79)
+        self.assertEqual(config["target_version"], ["py36", "py37", "py38"])
+        self.assertEqual(config["exclude"], r"\.pyi?$")
+        self.assertEqual(config["include"], r"\.py?$")
 
     def test_read_pyproject_toml(self) -> None:
         test_toml_file = THIS_DIR / "test.toml"
@@ -1282,6 +1286,22 @@ def test_read_pyproject_toml(self) -> None:
         self.assertEqual(config["check"], "no")
         self.assertEqual(config["diff"], "y")
         self.assertEqual(config["color"], "True")
+        self.assertEqual(config["line_length"], "79")
+        self.assertEqual(config["target_version"], ["py36", "py37", "py38"])
+        self.assertEqual(config["exclude"], r"\.pyi?$")
+        self.assertEqual(config["include"], r"\.py?$")
+
+    def test_black_replace_config(self) -> None:
+        test_toml_file = THIS_DIR / "test_replace.toml"
+        fake_ctx = FakeContext()
+        black.read_pyproject_toml(fake_ctx, FakeParameter(), str(test_toml_file))
+        config = fake_ctx.default_map
+        # `0` in `test_replace.toml` and `1` in `_black_config.toml`. Should be `1` as
+        # the one linked should overwrite the config
+        self.assertEqual(config["verbose"], "1")
+        self.assertEqual(config["check"], "no")
+        self.assertEqual(config["diff"], "y")
+        self.assertEqual(config["color"], "True")
         self.assertEqual(config["line_length"], "88")
         self.assertEqual(config["target_version"], ["py36", "py37", "py38"])
         self.assertEqual(config["exclude"], r"\.pyi?$")

tests/test_replace.toml

@@ -0,0 +1,4 @@
+[tool.black]
+config = "_black_config.toml"
+verbose = 0
+color = false