refactor: improve violation finder (#655)

* refactor(violations): link violation class to finders

* refactor(violations): move finder to dedicated module

python/deptry/core.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import logging
-import operator
 import sys
 from dataclasses import dataclass
 from typing import TYPE_CHECKING
@@ -13,22 +12,12 @@
 from deptry.python_file_finder import get_all_python_files_in
 from deptry.reporters import JSONReporter, TextReporter
 from deptry.stdlibs import STDLIBS_PYTHON
-from deptry.violations import (
-    DEP001MissingDependenciesFinder,
-    DEP001MissingDependencyViolation,
-    DEP002UnusedDependenciesFinder,
-    DEP002UnusedDependencyViolation,
-    DEP003TransitiveDependenciesFinder,
-    DEP003TransitiveDependencyViolation,
-    DEP004MisplacedDevDependenciesFinder,
-    DEP004MisplacedDevDependencyViolation,
-)
+from deptry.violations.finder import find_violations
 
 if TYPE_CHECKING:
     from collections.abc import Mapping
     from pathlib import Path
 
-    from deptry.dependency import Dependency
     from deptry.dependency_getter.base import DependenciesExtract
     from deptry.violations import Violation
 
@@ -89,7 +78,9 @@ def run(self) -> None:
             if not module_with_locations.module.standard_library
         ]
 
-        violations = self._find_violations(imported_modules_with_locations, dependencies_extract.dependencies)
+        violations = find_violations(
+            imported_modules_with_locations, dependencies_extract.dependencies, self.ignore, self.per_rule_ignores
+        )
         TextReporter(violations, use_ansi=not self.no_ansi).report()
 
         if self.json_output:
@@ -110,47 +101,6 @@ def _find_python_files(self) -> list[Path]:
 
         return python_files
 
-    def _find_violations(
-        self, imported_modules_with_locations: list[ModuleLocations], dependencies: list[Dependency]
-    ) -> list[Violation]:
-        violations = []
-
-        if DEP001MissingDependencyViolation.error_code not in self.ignore:
-            violations.extend(
-                DEP001MissingDependenciesFinder(
-                    imported_modules_with_locations, dependencies, self.per_rule_ignores.get("DEP001", ())
-                ).find()
-            )
-
-        if DEP002UnusedDependencyViolation.error_code not in self.ignore:
-            violations.extend(
-                DEP002UnusedDependenciesFinder(
-                    imported_modules_with_locations, dependencies, self.per_rule_ignores.get("DEP002", ())
-                ).find()
-            )
-
-        if DEP003TransitiveDependencyViolation.error_code not in self.ignore:
-            violations.extend(
-                DEP003TransitiveDependenciesFinder(
-                    imported_modules_with_locations, dependencies, self.per_rule_ignores.get("DEP003", ())
-                ).find()
-            )
-
-        if DEP004MisplacedDevDependencyViolation.error_code not in self.ignore:
-            violations.extend(
-                DEP004MisplacedDevDependenciesFinder(
-                    imported_modules_with_locations, dependencies, self.per_rule_ignores.get("DEP004", ())
-                ).find()
-            )
-
-        return self._get_sorted_violations(violations)
-
-    @staticmethod
-    def _get_sorted_violations(violations: list[Violation]) -> list[Violation]:
-        return sorted(
-            violations, key=operator.attrgetter("location.file", "location.line", "location.column", "error_code")
-        )
-
     def _get_local_modules(self) -> set[str]:
         """
         Get all local Python modules from the source directories and `known_first_party` list.

python/deptry/violations/__init__.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from deptry.violations.base import Violation
+from deptry.violations.base import Violation, ViolationsFinder
 from deptry.violations.dep001_missing.finder import DEP001MissingDependenciesFinder
 from deptry.violations.dep001_missing.violation import DEP001MissingDependencyViolation
 from deptry.violations.dep002_unused.finder import DEP002UnusedDependenciesFinder
@@ -20,5 +20,5 @@
     "DEP003TransitiveDependenciesFinder",
     "DEP004MisplacedDevDependenciesFinder",
     "Violation",
-    "ViolationFinder",
+    "ViolationsFinder",
 )

python/deptry/violations/base.py

@@ -26,6 +26,7 @@ class ViolationsFinder(ABC):
 
     """
 
+    violation: ClassVar[type[Violation]]
     imported_modules_with_locations: list[ModuleLocations]
     dependencies: list[Dependency]
     ignored_modules: tuple[str, ...] = ()

python/deptry/violations/dep001_missing/finder.py

@@ -18,6 +18,8 @@ class DEP001MissingDependenciesFinder(ViolationsFinder):
     Given a list of imported modules and a list of project dependencies, determine which ones are missing.
     """
 
+    violation = DEP001MissingDependencyViolation
+
     def find(self) -> list[Violation]:
         logging.debug("\nScanning for missing dependencies...")
         missing_dependencies: list[Violation] = []
@@ -29,7 +31,7 @@ def find(self) -> list[Violation]:
 
             if self._is_missing(module):
                 for location in module_with_locations.locations:
-                    missing_dependencies.append(DEP001MissingDependencyViolation(module, location))
+                    missing_dependencies.append(self.violation(module, location))
 
         return missing_dependencies
 

python/deptry/violations/dep002_unused/finder.py

@@ -27,6 +27,8 @@ class DEP002UnusedDependenciesFinder(ViolationsFinder):
     even if `matplotlib` itself is not imported anywhere.
     """
 
+    violation = DEP002UnusedDependencyViolation
+
     def find(self) -> list[Violation]:
         logging.debug("\nScanning for unused dependencies...")
         unused_dependencies: list[Violation] = []
@@ -35,9 +37,7 @@ def find(self) -> list[Violation]:
             logging.debug("Scanning module %s...", dependency.name)
 
             if self._is_unused(dependency):
-                unused_dependencies.append(
-                    DEP002UnusedDependencyViolation(dependency, Location(dependency.definition_file))
-                )
+                unused_dependencies.append(self.violation(dependency, Location(dependency.definition_file)))
 
         return unused_dependencies
 

python/deptry/violations/dep003_transitive/finder.py

@@ -25,6 +25,8 @@ class DEP003TransitiveDependenciesFinder(ViolationsFinder):
     Then it must be a transitive dependency.
     """
 
+    violation = DEP003TransitiveDependencyViolation
+
     def find(self) -> list[Violation]:
         logging.debug("\nScanning for transitive dependencies...")
         transitive_dependencies: list[Violation] = []
@@ -37,7 +39,7 @@ def find(self) -> list[Violation]:
             if self._is_transitive(module):
                 # `self._is_transitive` only returns `True` if the package is not None.
                 for location in module_with_locations.locations:
-                    transitive_dependencies.append(DEP003TransitiveDependencyViolation(module, location))
+                    transitive_dependencies.append(self.violation(module, location))
 
         return transitive_dependencies
 

python/deptry/violations/dep004_misplaced_dev/finder.py

@@ -21,6 +21,8 @@ class DEP004MisplacedDevDependenciesFinder(ViolationsFinder):
     This is the case for any development dependency encountered, since files solely used for development purposes should be excluded from scanning.
     """
 
+    violation = DEP004MisplacedDevDependencyViolation
+
     def find(self) -> list[Violation]:
         """
         In this function, we use 'corresponding_package_name' instead of module.package, since it can happen that a
@@ -38,7 +40,7 @@ def find(self) -> list[Violation]:
 
             if corresponding_package_name and self._is_development_dependency(module, corresponding_package_name):
                 for location in module_with_locations.locations:
-                    misplaced_dev_dependencies.append(DEP004MisplacedDevDependencyViolation(module, location))
+                    misplaced_dev_dependencies.append(self.violation(module, location))
 
         return misplaced_dev_dependencies
 

python/deptry/violations/finder.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+import operator
+from typing import TYPE_CHECKING
+
+from deptry.violations import (
+    DEP001MissingDependenciesFinder,
+    DEP002UnusedDependenciesFinder,
+    DEP003TransitiveDependenciesFinder,
+    DEP004MisplacedDevDependenciesFinder,
+)
+
+if TYPE_CHECKING:
+    from typing import Mapping
+
+    from deptry.dependency import Dependency
+    from deptry.module import ModuleLocations
+    from deptry.violations import Violation, ViolationsFinder
+
+
+_VIOLATIONS_FINDERS: tuple[type[ViolationsFinder], ...] = (
+    DEP001MissingDependenciesFinder,
+    DEP002UnusedDependenciesFinder,
+    DEP003TransitiveDependenciesFinder,
+    DEP004MisplacedDevDependenciesFinder,
+)
+
+
+def find_violations(
+    imported_modules_with_locations: list[ModuleLocations],
+    dependencies: list[Dependency],
+    ignore: tuple[str, ...],
+    per_rule_ignores: Mapping[str, tuple[str, ...]],
+) -> list[Violation]:
+    violations = []
+
+    for violation_finder in _VIOLATIONS_FINDERS:
+        if violation_finder.violation.error_code not in ignore:
+            violations.extend(
+                violation_finder(
+                    imported_modules_with_locations,
+                    dependencies,
+                    per_rule_ignores.get(violation_finder.violation.error_code, ()),
+                ).find()
+            )
+
+    return _get_sorted_violations(violations)
+
+
+def _get_sorted_violations(violations: list[Violation]) -> list[Violation]:
+    return sorted(
+        violations, key=operator.attrgetter("location.file", "location.line", "location.column", "error_code")
+    )

tests/unit/test_core.py

@@ -24,26 +24,6 @@
 from tests.utils import create_files, run_within_dir
 
 
-def test__get_sorted_violations() -> None:
-    violations = [
-        DEP004MisplacedDevDependencyViolation(Module("foo"), Location(Path("foo.py"), 1, 0)),
-        DEP001MissingDependencyViolation(Module("foo"), Location(Path("foo.py"), 2, 0)),
-        DEP001MissingDependencyViolation(Module("foo"), Location(Path("foo.py"), 1, 0)),
-        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 3, 1)),
-        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 2, 1)),
-        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 3, 0)),
-    ]
-
-    assert Core._get_sorted_violations(violations) == [
-        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 2, 1)),
-        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 3, 0)),
-        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 3, 1)),
-        DEP001MissingDependencyViolation(Module("foo"), Location(Path("foo.py"), 1, 0)),
-        DEP004MisplacedDevDependencyViolation(Module("foo"), Location(Path("foo.py"), 1, 0)),
-        DEP001MissingDependencyViolation(Module("foo"), Location(Path("foo.py"), 2, 0)),
-    ]
-
-
 @pytest.mark.parametrize(
     ("known_first_party", "root_suffix", "expected"),
     [

tests/unit/violations/test_finder.py

@@ -0,0 +1,28 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+from deptry.imports.location import Location
+from deptry.module import Module
+from deptry.violations import DEP001MissingDependencyViolation, DEP004MisplacedDevDependencyViolation
+from deptry.violations.finder import _get_sorted_violations
+
+
+def test__get_sorted_violations() -> None:
+    violations = [
+        DEP004MisplacedDevDependencyViolation(Module("foo"), Location(Path("foo.py"), 1, 0)),
+        DEP001MissingDependencyViolation(Module("foo"), Location(Path("foo.py"), 2, 0)),
+        DEP001MissingDependencyViolation(Module("foo"), Location(Path("foo.py"), 1, 0)),
+        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 3, 1)),
+        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 2, 1)),
+        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 3, 0)),
+    ]
+
+    assert _get_sorted_violations(violations) == [
+        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 2, 1)),
+        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 3, 0)),
+        DEP001MissingDependencyViolation(Module("foo"), Location(Path("bar.py"), 3, 1)),
+        DEP001MissingDependencyViolation(Module("foo"), Location(Path("foo.py"), 1, 0)),
+        DEP004MisplacedDevDependencyViolation(Module("foo"), Location(Path("foo.py"), 1, 0)),
+        DEP001MissingDependencyViolation(Module("foo"), Location(Path("foo.py"), 2, 0)),
+    ]