custom exceptions

Author: davidhyman

src/snippet/exceptions.py

@@ -0,0 +1,22 @@
+class SnippetError(Exception):
+    pass
+
+
+class DuplicateName(SnippetError):
+    pass
+
+
+class ValidationFailure(SnippetError):
+    pass
+
+
+class TagMismatch(SnippetError):
+    pass
+
+
+class StartEndMismatch(TagMismatch):
+    pass
+
+
+class CloakMismatch(TagMismatch):
+    pass

src/snippet/snippet.py

@@ -1,4 +1,5 @@
 from snippet.config import Config
+from snippet import exceptions
 
 
 def extract_snippets(config: Config, lines, path):
@@ -19,32 +20,32 @@ def extract_snippets(config: Config, lines, path):
             examples[current_key] = current_block
             current_strip = len(line) - len(line.lstrip())
             if capture:
-                raise Exception('Start/end example mismatch - already capturing at %s' % (current_key,))
+                raise exceptions.StartEndMismatch(f'Already capturing at {current_key}')
             capture = True
             continue
 
         if config.end_flag in line:
             # stop capturing, and discard empty blocks
             if not capture:
-                raise Exception('Start/end example mismatch - not yet capturing at %s' % (current_key,))
+                raise exceptions.StartEndMismatch(f'Not yet capturing at {current_key}')
             capture = False
             if not current_block:
                 examples.pop(current_key)
 
         if capture:
             # whilst capturing, append code lines to the current block
             if config.fail_on_dedent and any(line[:current_strip].split(' ')):
-                raise Exception('Unexpected dedent whilst capturing %s' % (current_key,))
+                raise exceptions.ValidationFailure(f'Unexpected dedent whilst capturing {current_key}')
             clean_line = line[current_strip:].rstrip()
             for r_before, r_after in config.replacements.items():
                 clean_line = clean_line.replace(r_before, r_after)
             for trigger in config.fail_on_contains:
                 if trigger in clean_line:
-                    raise Exception('Unexpected phrase %r at %s' % (trigger, current_key))
+                    raise exceptions.ValidationFailure(f'Unexpected phrase {repr(trigger)} at {current_key}')
             # add this line of code to the example block
             current_block.append(clean_line)
 
     if capture:
-        raise Exception('EOF reached whilst still capturing %s' % (current_key,))
+        raise exceptions.StartEndMismatch(f'EOF reached whilst still capturing {current_key}')
 
     return examples

src/snippet/workflow.py

@@ -5,6 +5,7 @@
 from snippet.config import Config
 from snippet.snippet import extract_snippets
 from snippet.wrapper import wrap
+from snippet import exceptions
 
 
 def run(config: Config):
@@ -30,7 +31,7 @@ def run(config: Config):
     for (path, line_num, example_name), code_lines in examples.items():
         existing = unique_example_names.get(example_name)
         if existing:
-            raise Exception('Example with duplicate name %s %s matches %s' % (path, line_num, existing))
+            raise exceptions.DuplicateName('Example with duplicate name %s %s matches %s' % (path, line_num, existing))
         else:
             unique_example_names[example_name] = (path, line_num, example_name)
 

tests/test_workflow.py

@@ -2,7 +2,8 @@
 import os
 import unittest
 
-from snippet.workflow import run
+from snippet import exceptions
+from snippet import workflow
 from snippet.config import Config
 
 from tests import test_parser as P
@@ -31,7 +32,7 @@ def test_read(self):
         config.input_glob = self.tmp_fp
         config.output_dir = self.tmpdir.name
 
-        examples, paths, failures = run(config)
+        examples, paths, failures = workflow.run(config)
 
         with self.subTest(part='found the file'):
             self.assertEqual([self.tmp_fp], paths)
@@ -55,5 +56,5 @@ class TestDuplicateNames(Test):
     text = text + '\n' + text
 
     def test_read(self):
-        with self.assertRaises(Exception):
+        with self.assertRaises(exceptions.DuplicateName):
             super().test_read()