From 0ac4b327bc313757c958bee10729c0b9aa96407d Mon Sep 17 00:00:00 2001
From: Eric Proulx <playmaverick@gmail.com>
Date: Sat, 13 Dec 2025 23:10:51 +0100
Subject: [PATCH] Revert PR #2577: Restore support for  in endpoint blocks

---
 CHANGELOG.md                |  1 +
 lib/grape/endpoint.rb       | 16 +++++++++++-----
 spec/grape/endpoint_spec.rb | 20 ++------------------
 3 files changed, 14 insertions(+), 23 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cdc6880a9..c4e6cce5b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@
 #### Fixes
     
 * [#2633](https://github.com/ruby-grape/grape/pull/2633): Fix cascade reading - [@ericproulx](https://github.com/ericproulx).
+* [#2641](https://github.com/ruby-grape/grape/pull/2641): Restore support for `return` in endpoint blocks - [@ericproulx](https://github.com/ericproulx).
 * [#2642](https://github.com/ruby-grape/grape/pull/2642): Fix array allocation in base_route.rb - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
 
diff --git a/lib/grape/endpoint.rb b/lib/grape/endpoint.rb
index 24307185c..873f4b4db 100644
--- a/lib/grape/endpoint.rb
+++ b/lib/grape/endpoint.rb
@@ -32,6 +32,15 @@ def run_before_each(endpoint)
         superclass.run_before_each(endpoint) unless self == Endpoint
         before_each.each { |blk| blk.try(:call, endpoint) }
       end
+
+      def block_to_unbound_method(block)
+        return unless block
+
+        define_method :temp_unbound_method, block
+        method = instance_method(:temp_unbound_method)
+        remove_method :temp_unbound_method
+        method
+      end
     end
 
     # Create a new endpoint.
@@ -70,7 +79,7 @@ def initialize(new_settings, **options, &block)
       @status = nil
       @stream = nil
       @body = nil
-      @source = block
+      @source = self.class.block_to_unbound_method(block)
       @before_filter_passed = false
     end
 
@@ -190,10 +199,7 @@ def execute
       return unless @source
 
       ActiveSupport::Notifications.instrument('endpoint_render.grape', endpoint: self) do
-        instance_exec(&@source)
-      rescue LocalJumpError => e
-        Grape.deprecator.warn 'Using `return` in an endpoint has been deprecated. Use `next` instead.'
-        return e.exit_value
+        @source.bind_call(self)
       end
     end
 
diff --git a/spec/grape/endpoint_spec.rb b/spec/grape/endpoint_spec.rb
index 8ef338dd4..b82672aa1 100644
--- a/spec/grape/endpoint_spec.rb
+++ b/spec/grape/endpoint_spec.rb
@@ -762,28 +762,12 @@ def memoized
     expect(last_response.body).to eq('yo')
   end
 
-  context 'when `return`' do
-    it 'calls deprecator' do
+  context 'when calling return' do
+    it 'does not raise a LocalJumpError' do
       subject.get('/home') do
         return 'Hello'
       end
 
-      expect(Grape.deprecator).to receive(:warn).with('Using `return` in an endpoint has been deprecated. Use `next` instead.')
-
-      get '/home'
-      expect(last_response.status).to eq(200)
-      expect(last_response.body).to eq('Hello')
-    end
-  end
-
-  context 'when `next`' do
-    it 'does not call deprecator' do
-      subject.get('/home') do
-        next 'Hello'
-      end
-
-      expect(Grape.deprecator).not_to receive(:warn)
-
       get '/home'
       expect(last_response.status).to eq(200)
       expect(last_response.body).to eq('Hello')