Drop Enumerable from Grape::Exceptions::ValidationErrors

CHANGELOG.md

@@ -43,6 +43,7 @@
 * [#2726](https://github.com/ruby-grape/grape/pull/2726): Reuse one `AttributesIterator` per validator and drop the unused `Enumerable` mixin - [@ericproulx](https://github.com/ericproulx).
 * [#2728](https://github.com/ruby-grape/grape/pull/2728): Deprecate passing a positional options Hash to `auth`/`http_basic`/`http_digest`; pass keyword arguments instead - [@ericproulx](https://github.com/ericproulx).
 * [#2733](https://github.com/ruby-grape/grape/pull/2733): Drop the dead `active_support/core_ext/hash/reverse_merge` require; call `ActiveSupport::HashWithIndifferentAccess.new(...)` directly at call sites - [@ericproulx](https://github.com/ericproulx).
+* [#2747](https://github.com/ruby-grape/grape/pull/2747): Drop `Enumerable` from `Grape::Exceptions::ValidationErrors` and remove its public `#each`; rewrite `#full_messages` to walk `#errors` directly - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
 
 #### Fixes

UPGRADING.md

@@ -3,6 +3,26 @@ Upgrading Grape
 
 ### Upgrading to >= 3.3
 
+#### `Grape::Exceptions::ValidationErrors` no longer mixes in `Enumerable`
+
+`Grape::Exceptions::ValidationErrors` no longer includes `Enumerable` and no longer defines a public `#each`. The Enumerable surface (`#each`, `#map`, `#select`, `#to_a`, etc.) was undocumented and untested; the documented accessors — `#errors`, `#full_messages`, `#message`, `#as_json` — are unchanged.
+
+If a `rescue_from` block iterated over the exception instance, switch to `#errors`:
+
+```ruby
+# before
+rescue_from Grape::Exceptions::ValidationErrors do |e|
+  e.each { |attribute, error| ... }
+end
+
+# after
+rescue_from Grape::Exceptions::ValidationErrors do |e|
+  e.errors.each do |attributes, errs|
+    errs.each { |error| ... }
+  end
+end
+```
+
 #### `auth`, `http_basic` and `http_digest` now take keyword arguments
 
 `Grape::Middleware::Auth::DSL#auth`, `#http_basic` and `#http_digest` now accept their options as keyword arguments instead of a positional `Hash`. Calls using bare keyword syntax or a block are unaffected:

lib/grape/exceptions/validation_errors.rb

@@ -3,23 +3,13 @@
 module Grape
   module Exceptions
     class ValidationErrors < Base
-      include Enumerable
-
       attr_reader :errors
 
       def initialize(errors: [], headers: {})
         @errors = errors.group_by(&:params)
         super(message: full_messages.join(', '), status: 400, headers:)
       end
 
-      def each
-        errors.each_pair do |attribute, errors|
-          errors.each do |error|
-            yield attribute, error
-          end
-        end
-      end
-
       def as_json(**_opts)
         errors.map do |k, v|
           {
@@ -34,14 +24,16 @@ def to_json(*_opts)
       end
 
       def full_messages
-        messages = map do |attributes, error|
-          translate(
-            :format,
-            scope: 'grape.errors',
-            default: '%<attributes>s %<message>s',
-            attributes: translate_attributes(attributes),
-            message: error.message
-          )
+        messages = errors.flat_map do |attributes, errs|
+          errs.map do |error|
+            translate(
+              :format,
+              scope: 'grape.errors',
+              default: '%<attributes>s %<message>s',
+              attributes: translate_attributes(attributes),
+              message: error.message
+            )
+          end
         end
         messages.uniq!
         messages