PEP518 compliant pyproject format (continued)

README.md

@@ -3,16 +3,18 @@
 A command line tool for checking coverage reports against configurable coverage minimums.
 Currently built for use around python's [coverage](https://pypi.org/project/coverage/)
 
-
 ### Installation
+
 `pip install coverage-threshold`
 
 also recommended:
 
 `pip install coverage`
 
 ### Usage
+
 Typical execution:
+
 ```bash
 coverage run -m pytest tests/  # or any test runner here
 coverage json
@@ -52,34 +54,34 @@ optional arguments:
   --config CONFIG       path to config file (default: ./pyproject.toml)
 ```
 
-
 ### Config
 
 the current expected config file format is [toml](https://toml.io/en/)
 the default config file used is `pyproject.toml` but and alternative path can be specified with `--config`
 
 example config:
+
 ```toml
-[coverage-threshold]
+[tool.coverage-threshold]
 line_coverage_min = 95
 file_line_coverage_min = 95
 branch_coverage_min = 50
 
-    [coverage-threshold.modules."src/cli/"]
-    file_line_coverage_min = 40
+[tool.coverage-threshold.modules."src/cli/"]
+file_line_coverage_min = 40
 
-    [coverage-threshold.modules."src/cli/my_command.py"]
-    file_line_coverage_min = 100
+[tool.coverage-threshold.modules."src/cli/my_command.py"]
+file_line_coverage_min = 100
 
-    [coverage-threshold.modules."src/lib/"]
-    file_line_coverage_min = 100
-    file_branch_coverage_min = 100
+[tool.coverage-threshold.modules."src/lib/"]
+file_line_coverage_min = 100
+file_branch_coverage_min = 100
 
-    [coverage-threshold.modules."src/model/"]
-    file_line_coverage_min = 100
+[tool.coverage-threshold.modules."src/model/"]
+file_line_coverage_min = 100
 
-    [coverage-threshold.modules."src/__main__.py"]
-    file_line_coverage_min = 0
+[tool.coverage-threshold.modules."src/__main__.py"]
+file_line_coverage_min = 0
 ```
 
 Each string key in `config.modules` is treated as a path prefix, where the longest matching prefix is used to configure the coverage thresholds for each file

coverage_threshold/cli/read_config.py

@@ -9,11 +9,18 @@
 def read_config(config_file_name: Optional[str]) -> Config:
     DEFAULT_FILENAME = "./pyproject.toml"
     if config_file_name is not None:
-        return Config.parse(toml.load(config_file_name)["coverage-threshold"])
+        if not os.path.isfile(config_file_name):
+            raise FileNotFoundError(f"Config file {config_file_name} not found")
     else:
-        if os.path.isfile(DEFAULT_FILENAME):
-            return Config.parse(
-                toml.load(DEFAULT_FILENAME).get("coverage-threshold", {})
-            )
-        else:
-            return Config()
+        config_file_name = DEFAULT_FILENAME
+    if os.path.isfile(config_file_name):
+        toml_dict = toml.load(config_file_name)
+        try:
+            # PEP 518 compliant version
+            config_dict = toml_dict["tool"]["coverage-threshold"]
+        except KeyError:
+            # Legacy version
+            config_dict = toml_dict.get("coverage-threshold", {})
+        return Config.parse(config_dict)
+    else:
+        return Config()

example_project/pyproject.toml

@@ -1,2 +1,2 @@
-[coverage-threshold]
+[tool.coverage-threshold]
 line_coverage_min = 75.0

pyproject.toml

@@ -6,15 +6,15 @@ build-backend = "setuptools.build_meta"
 profile = "black"
 src_paths = ["coverage_threshold", "tests"]
 
-[coverage-threshold]
+[tool.coverage-threshold]
 line_coverage_min = 0
 file_line_coverage_min = 100
 file_branch_coverage_min = 100
 
-    [coverage-threshold.modules."coverage_threshold/cli/"]
-    file_line_coverage_min = 0
-    file_branch_coverage_min = 0
+[tool.coverage-threshold.modules."coverage_threshold/cli/"]
+file_line_coverage_min = 0
+file_branch_coverage_min = 0
 
-    [coverage-threshold.modules."coverage_threshold/__main__.py"]
-    file_line_coverage_min = 0
-    file_branch_coverage_min = 0
+[tool.coverage-threshold.modules."coverage_threshold/__main__.py"]
+file_line_coverage_min = 0
+file_branch_coverage_min = 0

tests/unit/config/complex.pyproject.toml

@@ -0,0 +1,20 @@
+[tool.coverage-threshold]
+line_coverage_min = 95
+file_line_coverage_min = 95
+branch_coverage_min = 50
+
+[tool.coverage-threshold.modules."src/cli/"]
+file_line_coverage_min = 40
+
+[tool.coverage-threshold.modules."src/cli/my_command.py"]
+file_line_coverage_min = 100
+
+[tool.coverage-threshold.modules."src/lib/"]
+file_line_coverage_min = 100
+file_branch_coverage_min = 100
+
+[tool.coverage-threshold.modules."src/model/"]
+file_line_coverage_min = 100
+
+[tool.coverage-threshold.modules."src/__main__.py"]
+file_line_coverage_min = 0

tests/unit/config/legacy.pyproject.toml

@@ -0,0 +1,2 @@
+[coverage-threshold]
+line_coverage_min = 75.0

tests/unit/config/pyproject.toml

@@ -0,0 +1,2 @@
+[tool.coverage-threshold]
+line_coverage_min = 75.0

tests/unit/config/test_read_config.py

@@ -0,0 +1,37 @@
+import os
+from decimal import Decimal
+
+from coverage_threshold.cli.read_config import read_config
+
+
+def test_read_config_parses_default_pyproject_format() -> None:
+    config = read_config(path_to_test_config("pyproject.toml"))
+    assert config.line_coverage_min == Decimal("75.0")
+    assert config.modules is None
+
+
+# backwards compatibilty for before this project became compliant with pep518
+def test_read_config_parses_legacy_pyproject_format() -> None:
+    config = read_config(path_to_test_config("legacy.pyproject.toml"))
+    assert config.line_coverage_min == Decimal("75.0")
+    assert config.modules is None
+
+
+def test_read_config_parses_complex_pyproject_format() -> None:
+    config = read_config(path_to_test_config("complex.pyproject.toml"))
+    assert config.line_coverage_min == Decimal("95.0")
+    assert config.file_line_coverage_min == Decimal("95.0")
+    assert config.branch_coverage_min == Decimal("50.0")
+    assert config.modules is not None
+    assert config.modules["src/cli/"].file_line_coverage_min == Decimal("40.0")
+    assert config.modules["src/cli/my_command.py"].file_line_coverage_min == Decimal(
+        "100"
+    )
+    assert config.modules["src/lib/"].file_line_coverage_min == Decimal("100")
+    assert config.modules["src/lib/"].file_branch_coverage_min == Decimal("100")
+    assert config.modules["src/model/"].file_line_coverage_min == Decimal("100")
+    assert config.modules["src/__main__.py"].file_line_coverage_min == Decimal("0")
+
+
+def path_to_test_config(filename: str) -> str:
+    return os.path.join(os.path.dirname(__file__), filename)