Rescue truly all exceptions

Author: mtsmfm

CHANGELOG.md

@@ -14,6 +14,7 @@
 * [#1752](https://github.com/ruby-grape/grape/pull/1752): Fix `include_missing` behavior for aliased parameters - [@jonasoberschweiber](https://github.com/jonasoberschweiber).
 * [#1754](https://github.com/ruby-grape/grape/pull/1754): Allow rescue from non-`StandardError` exceptions to use default error handling - [@jelkster](https://github.com/jelkster).
 * [#1756](https://github.com/ruby-grape/grape/pull/1756): Allow custom Grape exception handlers when the built-in exception handling is enabled - [@soylent](https://github.com/soylent).
+* [#1745](https://github.com/ruby-grape/grape/pull/1745): Rescue truly all exceptions - [@mtsmfm](https://github.com/mtsmfm).
 * Your contribution here.
 
 ### 1.0.2 (1/10/2018)

README.md

@@ -2086,7 +2086,7 @@ literally accepts every request.
 
 ## Exception Handling
 
-Grape can be told to rescue all `StandardError` exceptions and return them in the API format.
+Grape can be told to rescue all exceptions and return them in the API format.
 
 ```ruby
 class Twitter::API < Grape::API
@@ -2116,7 +2116,7 @@ class Twitter::API < Grape::API
 end
 ```
 
-In this case ```UserDefinedError``` must be inherited from ```StandardError```.
+```UserDefinedError``` can be inherited from any exception class.
 
 Notice that you could combine these two approaches (rescuing custom errors takes precedence). For example, it's useful for handling all exceptions except Grape validation errors.
 

lib/grape/middleware/error.rb

@@ -110,7 +110,7 @@ def rescue_handler_for_grape_exception(klass)
       end
 
       def rescue_handler_for_any_class(klass)
-        return unless klass <= StandardError
+        return unless klass <= Exception
         return unless options[:rescue_all] || options[:rescue_grape_exceptions]
 
         options[:all_rescue_handler] || :default_rescue_handler

spec/grape/middleware/exception_spec.rb

@@ -103,8 +103,13 @@ def app
           run ExceptionSpec::OtherExceptionApp
         end
       end
-      it 'does not trap errors other than StandardError' do
-        expect { get '/' }.to raise_error(NotImplementedError, 'snow!')
+      it 'sets the message appropriately' do
+        get '/'
+        expect(last_response.body).to eq('snow!')
+      end
+      it 'defaults to a 500 status' do
+        get '/'
+        expect(last_response.status).to eq(500)
       end
     end
   end