From 04e69ea120ad2e32348932a82930b7526456766e Mon Sep 17 00:00:00 2001
From: ouyangjinting <Ou.Yang.Jin.Ting.X@gmail.com>
Date: Sun, 28 Jul 2024 04:39:43 +0800
Subject: [PATCH] The `length` validator only takes effect for parameters with
 types that support `#length` method (#2464)

---
 CHANGELOG.md                                         | 1 +
 UPGRADING.md                                         | 8 ++++++++
 lib/grape/validations/validators/length_validator.rb | 2 +-
 spec/grape/validations/validators/length_spec.rb     | 4 ++--
 4 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 22ea580d92..48d1b804e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@
 * [#2471](https://github.com/ruby-grape/grape/pull/2471): Fix absence of original_exception and/or backtrace even if passed in error! - [@numbata](https://github.com/numbata).
 * [#2478](https://github.com/ruby-grape/grape/pull/2478): Fix rescue_from with invalid response - [@ericproulx](https://github.com/ericproulx).
 * [#2480](https://github.com/ruby-grape/grape/pull/2480): Fix rescue_from ValidationErrors exception - [@numbata](https://github.com/numbata).
+* [#2464](https://github.com/ruby-grape/grape/pull/2464): The `length` validator only takes effect for parameters with types that support `#length` method - [@OuYangJinTing](https://github.com/OuYangJinTing).
 * Your contribution here.
 
 ### 2.1.3 (2024-07-13)
diff --git a/UPGRADING.md b/UPGRADING.md
index be2fb564de..cba4774bbe 100644
--- a/UPGRADING.md
+++ b/UPGRADING.md
@@ -1,6 +1,14 @@
 Upgrading Grape
 ===============
 
+### Upgrading to >= 2.2.0
+
+### `Length` validator
+
+After Grape 2.2.0, `length` validator will only take effect for parameters with types that support `#length` method, will not throw `ArgumentError` exception.
+
+See [#2464](https://github.com/ruby-grape/grape/pull/2464) for more information.
+
 ### Upgrading to >= 2.1.0
 
 #### Optional Builder
diff --git a/lib/grape/validations/validators/length_validator.rb b/lib/grape/validations/validators/length_validator.rb
index bcd0c95592..ed266fe842 100644
--- a/lib/grape/validations/validators/length_validator.rb
+++ b/lib/grape/validations/validators/length_validator.rb
@@ -18,7 +18,7 @@ def initialize(attrs, options, required, scope, **opts)
         def validate_param!(attr_name, params)
           param = params[attr_name]
 
-          raise ArgumentError, "parameter #{param} does not support #length" unless param.respond_to?(:length)
+          return unless param.respond_to?(:length)
 
           return unless (!@min.nil? && param.length < @min) || (!@max.nil? && param.length > @max)
 
diff --git a/spec/grape/validations/validators/length_spec.rb b/spec/grape/validations/validators/length_spec.rb
index 8fa9f84876..9334b7a204 100644
--- a/spec/grape/validations/validators/length_spec.rb
+++ b/spec/grape/validations/validators/length_spec.rb
@@ -188,11 +188,11 @@
   end
 
   describe '/type_is_not_array' do
-    context 'raises an error' do
+    context 'does not raise an error' do
       it do
         expect do
           post 'type_is_not_array', list: 12
-        end.to raise_error(ArgumentError, 'parameter 12 does not support #length')
+        end.not_to raise_error
       end
     end
   end