Fix before_each method to handle nil parameter correctly

- Fix NoMethodError when calling before_each(nil) by clearing the array instead of assigning nil
- Update test expectations to be more specific about error types and messages

Author: ericproulx

PR_DESCRIPTION.md

@@ -0,0 +1,19 @@
+# Fix before_each method to handle nil parameter correctly
+
+## Problem
+
+When calling `before_each(nil)` to clear the before_each callbacks, a `NoMethodError` was raised because the code attempted to assign `nil` to `@before_each` instead of clearing the array.
+
+## Solution
+
+- Modified the `before_each` method in `lib/grape/endpoint.rb` to properly handle the `nil` parameter by clearing the `@before_each` array instead of assigning `nil`
+- Updated test expectations in `spec/grape/endpoint_spec.rb` to be more specific about error types (`NameError` vs `NoMethodError`) and include error message patterns for better test reliability
+
+## Changes
+
+- `lib/grape/endpoint.rb`: Added `else` clause to clear `@before_each` when `new_setup` is `nil`
+- `spec/grape/endpoint_spec.rb`: Updated error expectations to match specific error types and messages
+
+## Testing
+
+All existing tests pass, and the fix ensures that `before_each(nil)` correctly clears the callbacks without raising an error.

lib/grape/endpoint.rb

@@ -23,8 +23,10 @@ def before_each(new_setup = false, &block)
           return @before_each unless block
 
           @before_each << block
-        else
+        elsif new_setup
           @before_each = [new_setup]
+        else
+          @before_each.clear
         end
       end
 

spec/grape/endpoint_spec.rb

@@ -24,7 +24,7 @@ def app
 
     it 'is able to override a helper' do
       subject.get('/') { current_user }
-      expect { get '/' }.to raise_error(NameError)
+      expect { get '/' }.to raise_error(NameError, /undefined local variable or method 'current_user'/)
 
       described_class.before_each do |endpoint|
         allow(endpoint).to receive(:current_user).and_return('Bob')
@@ -34,15 +34,15 @@ def app
       expect(last_response.body).to eq('Bob')
 
       described_class.before_each(nil)
-      expect { get '/' }.to raise_error(NameError)
+      expect { get '/' }.to raise_error(NameError, /undefined local variable or method 'current_user'/)
     end
 
     it 'is able to stack helper' do
       subject.get('/') do
         authenticate_user!
         current_user
       end
-      expect { get '/' }.to raise_error(NameError)
+      expect { get '/' }.to raise_error(NoMethodError, /undefined method 'authenticate_user!' for/)
 
       described_class.before_each do |endpoint|
         allow(endpoint).to receive(:current_user).and_return('Bob')
@@ -56,7 +56,7 @@ def app
       expect(last_response.body).to eq('Bob')
 
       described_class.before_each(nil)
-      expect { get '/' }.to raise_error(NameError)
+      expect { get '/' }.to raise_error(NoMethodError, /undefined method 'authenticate_user!' for/)
     end
   end