feat(fixers): capture exceptions

src/tryceratops/fixers/base.py

@@ -5,6 +5,8 @@
 from tryceratops.processors import Processor
 from tryceratops.violations import Violation
 
+from .exceptions import FixerFixException
+
 ViolationType = TypeVar("ViolationType", bound=Violation)
 GroupedViolations = dict[str, List[ViolationType]]
 
@@ -48,11 +50,14 @@ def _group_violations_by_filename(self, violations: List[Violation]) -> GroupedV
     def _process_group(self, filename: str, violations: List[ViolationType]):
         with FileFixerHandler(filename) as file:
             for violation in violations:
-                file_lines = file.read_lines()
-                resulting_lines = self.perform_fix(file_lines, violation)
-                file.write_fix(resulting_lines)
-
-                self.fixes_made += 1
+                try:
+                    file_lines = file.read_lines()
+                    resulting_lines = self.perform_fix(file_lines, violation)
+                    file.write_fix(resulting_lines)
+                except Exception as ex:
+                    raise FixerFixException(violation, filename) from ex
+                else:
+                    self.fixes_made += 1
 
     @abstractmethod
     def perform_fix(self, lines: List[str], violation: ViolationType) -> List[str]:

src/tryceratops/fixers/exceptions.py

@@ -0,0 +1,12 @@
+from tryceratops.violations import Violation
+
+
+class FixerException(Exception):
+    pass
+
+
+class FixerFixException(FixerException):
+    def __init__(self, violation: Violation, filename: str):
+        self.violation = violation
+        self.filename = filename
+        super().__init__(f"Attempt to fix violation {violation} on file {filename} failed")