server/errors: add and document error codes

API.md

@@ -120,11 +120,58 @@ code together with JSON of following structure:
 
 ```json5
 {
+    "name": "Name of the error, e.g. 'PostNotFoundError'",
     "title": "Generic title of error message, e.g. 'Not found'",
     "description": "Detailed description of what went wrong, e.g. 'User `rr-` not found."
 }
 ```
 
+List of possible error names:
+
+- `MissingRequiredFileError`
+- `MissingRequiredParameterError`
+- `InvalidParameterError` (when trying to pass text when integer is expected etc.)
+- `IntegrityError` (race conditions when editing the same resource)
+- `SearchError`
+- `AuthError`
+- `PostNotFoundError`
+- `PostAlreadyFeaturedError`
+- `PostAlreadyUploadedError`
+- `InvalidPostIdError`
+- `InvalidPostSafetyError`
+- `InvalidPostSourceError`
+- `InvalidPostContentError`
+- `InvalidPostRelationError`
+- `InvalidPostNoteError`
+- `InvalidPostFlagError`
+- `InvalidFavoriteTargetError`
+- `InvalidCommentIdError`
+- `CommentNotFoundError`
+- `EmptyCommentTextError`
+- `InvalidScoreTargetError`
+- `InvalidScoreValueError`
+- `TagCategoryNotFoundError`
+- `TagCategoryAlreadyExistsError`
+- `TagCategoryIsInUseError`
+- `InvalidTagCategoryNameError`
+- `InvalidTagCategoryColorError`
+- `TagNotFoundError`
+- `TagAlreadyExistsError`
+- `TagIsInUseError`
+- `InvalidTagNameError`
+- `InvalidTagRelationError`
+- `InvalidTagCategoryError`
+- `InvalidTagDescriptionError`
+- `UserNotFoundError`
+- `UserAlreadyExistsError`
+- `InvalidUserNameError`
+- `InvalidEmailError`
+- `InvalidPasswordError`
+- `InvalidRankError`
+- `InvalidAvatarError`
+- `ValidationError` (catch all for odd validation errors)
+
+
 ## Field selecting
 
 For performance considerations, sometimes the client might want to choose the

server/szurubooru/facade.py

@@ -11,6 +11,7 @@ from szurubooru import api, middleware
 
 def _map_error(ex, target_class, title):
     return target_class(
+        name=type(ex).__name__,
         title=title,
         description=str(ex),
         extra_fields=getattr(ex, 'extra_fields', {}))
@@ -42,7 +43,11 @@ def _on_processing_error(ex):
 
 def _on_stale_data_error(_ex):
     raise rest.errors.HttpConflict(
-        'Someone else modified this in the meantime. Please try again.')
+        name='IntegrityError',
+        title='Integrity violation',
+        description=(
+            'Someone else modified this in the meantime. '
+            'Please try again.'))
 
 
 def validate_config():

server/szurubooru/func/versions.py

@@ -5,7 +5,7 @@ def verify_version(entity, context, field_name='version'):
     actual_version = context.get_param_as_int(field_name, required=True)
     expected_version = entity.version
     if actual_version != expected_version:
-        raise errors.InvalidParameterError(
+        raise errors.IntegrityError(
             'Someone else modified this in the meantime. ' +
             'Please try again.')
 

server/szurubooru/rest/app.py

@@ -103,6 +103,7 @@ def application(env, start_response):
             '%d %s' % (ex.code, ex.reason),
             [('content-type', 'application/json')])
         blob = {
+            'name': ex.name,
             'title': ex.title,
             'description': ex.description,
         }

server/szurubooru/rest/errors.py

@@ -5,10 +5,15 @@ class BaseHttpError(RuntimeError):
     code = None
     reason = None
 
-    def __init__(self, description, title=None, extra_fields=None):
+    def __init__(self, name, description, title=None, extra_fields=None):
         super().__init__()
+        # error name for programmers
+        self.name = name
+        # error description for humans
         self.description = description
+        # short title for humans
         self.title = title or self.reason
+        # additional fields for programmers
         self.extra_fields = extra_fields