Adds unique tests names validator

.gitignore

@@ -102,4 +102,7 @@ venv.bak/
 /site
 
 # mypy
-.mypy_cache/
+.mypy_cache/
+
+# IDE
+.idea

.travis.yml

@@ -4,6 +4,7 @@ python:
   - "3.7"
   - "3.8"
 install:
+  - gem install chef-utils -v 16.6.14
   - gem install mdl
   - pip install -r requirements.txt
   - pip install -e .

README.md

@@ -107,6 +107,8 @@ tests/test_unit/test_something.py:2:0: FP009 test_something should use fixtures
 as follows: @pytest.mark.usefixtures('fixture_one')
 ```
 
+7) validates that test function uses unique names
+
 ## Installation
 
 ```terminal

flake8_fine_pytest/checker.py

@@ -4,6 +4,7 @@
 
 from flake8_fine_pytest import __version__ as version
 from flake8_fine_pytest.watchers.modules_structure import ModulesStructureWatcher
+from flake8_fine_pytest.watchers.unique_test_names import UniqueTestNamesWatcher
 from flake8_fine_pytest.watchers.xfail_decorator import XfailWatcher
 from flake8_fine_pytest.watchers.xfail_until_argument_watcher import (
     XfailUntilArgumentWatcher,
@@ -26,6 +27,7 @@ class FinePytestChecker:
         AssertCountWatcher,
         XfailUntilArgumentWatcher,
         UsefixturesWatcher,
+        UniqueTestNamesWatcher,
     )
 
     def __init__(self, tree: ast.AST, filename: str):

flake8_fine_pytest/watchers/unique_test_names.py

@@ -0,0 +1,27 @@
+import ast
+from typing import Set
+
+from flake8_fine_pytest.watchers.base import BaseWatcher
+
+
+class UniqueTestNamesWatcher(BaseWatcher):
+    error_template = 'FP009 Duplicate name test case ({})'
+
+    def run(self) -> None:
+        testcases_names: Set[str] = set()
+
+        if not self._is_test_file(self.filename):
+            return
+
+        for node in ast.walk(self.tree):
+            if not self._should_check_node(node):
+                continue
+
+            node_name = node.name  # type: ignore
+
+            if node_name not in testcases_names:
+                testcases_names.add(node_name)
+                continue
+
+            error_msg = self.error_template.format(node_name)
+            self.add_error((node.lineno, 0, error_msg))

tests/test_files/test_not_unique.py

@@ -0,0 +1,19 @@
+import pytest
+
+
+def test_not_uniq():
+    pass
+
+
+def test_not_uniq():
+    pass
+
+
+@pytest.mark.skip
+def test_not_uniq_with_decorator():
+    pass
+
+
+@pytest.mark.skip
+def test_not_uniq_with_decorator():
+    pass

tests/test_integration/test_unique_names.py

@@ -0,0 +1,6 @@
+def test_unique_names(run_validator_for_test_files):
+    errors = run_validator_for_test_files('test_not_unique.py')
+
+    assert len(errors) == 2
+    assert errors[0][2] == 'FP009 Duplicate name test case (test_not_uniq)'
+    assert errors[1][2] == 'FP009 Duplicate name test case (test_not_uniq_with_decorator)'