build: omit certain lines/files from code coverage #313

- This commit adds a dev dependency which is used to conditionally exclude lines of code from test coverage reporting. There is a particular line of code in `models.py` which is only used in Python 3.7+, so for 3.6, this line can be excluded from coverage checks

datagateway_api/src/search_api/models.py

@@ -15,7 +15,7 @@ def _is_panosc_entity_field_of_type_list(entity_field):
         hasattr(entity_field_outer_type, "_name")
         and entity_field_outer_type._name == "List"
     ):
-        is_list = True
+        is_list = True  # pragma: py-37-code
     # The `_name` `outer_type_` attribute was introduced in Python 3.7 so to check
     # whether the field is of type list in Python 3.6, we are checking the type of its
     # default value. We must ensure that any new list fields that get added in future

pyproject.toml

@@ -56,6 +56,7 @@ coverage = {extras = ["toml"], version = "^5.3"}
 pytest-cov = "^2.10.1"
 pytest-icdiff = "^0.5"
 python-semantic-release = "^7.19.2"
+coverage-conditional-plugin = "^0.5.0"
 
 [tool.poetry.scripts]
 
@@ -69,6 +70,16 @@ source = ["datagateway_api"]
 [tool.coverage.run]
 branch = true
 source = ["datagateway_api"]
+plugins = ["coverage_conditional_plugin"]
+omit = [
+    "*api_start_utils.py",
+    "*logger_setup.py",
+    "*main.py",
+    "*wsgi.py",
+]
+
+[tool.coverage.coverage_conditional_plugin.rules]
+py-37-code = "sys_version_info > (3, 6)"
 
 [tool.coverage.report]
 show_missing = true