Merge pull request #1725 from Jelkster/rescue-all-doc-fix

`rescue_from :all` documentation fix

Author: dblock

CHANGELOG.md

@@ -12,6 +12,7 @@
 * [#1710](https://github.com/ruby-grape/grape/pull/1710): Fix wrong transformation of empty Array in declared params - [@pablonahuelgomez](https://github.com/pablonahuelgomez).
 * [#1722](https://github.com/ruby-grape/grape/pull/1722): Fix catch-all hiding multiple versions of an endpoint after the first definition - [@zherr](https://github.com/zherr).
 * [#1724](https://github.com/ruby-grape/grape/pull/1724): Optional nested array validation - [@ericproulx](https://github.com/ericproulx).
+* [#1725](https://github.com/ruby-grape/grape/pull/1725): Fix `rescue_from :all` documentation - [@Jelkster](https://github.com/Jelkster).
 * Your contribution here.
 
 ### 1.0.1 (9/8/2017)

README.md

@@ -2071,7 +2071,7 @@ literally accepts every request.
 
 ## Exception Handling
 
-Grape can be told to rescue all exceptions and return them in the API format.
+Grape can be told to rescue all `StandardError` exceptions and return them in the API format.
 
 ```ruby
 class Twitter::API < Grape::API
@@ -2177,8 +2177,8 @@ class Twitter::API < Grape::API
     error!("ArgumentError: #{e.message}")
   end
 
-  rescue_from NotImplementedError do |e|
-    error!("NotImplementedError: #{e.message}")
+  rescue_from NoMethodError do |e|
+    error!("NoMethodError: #{e.message}")
   end
 end
 ```

spec/grape/middleware/exception_spec.rb

@@ -11,6 +11,15 @@ def call(_env)
       end
     end
 
+    # raises a non-StandardError (ScriptError) exception
+    class OtherExceptionApp
+      class << self
+        def call(_env)
+          raise NotImplementedError, 'snow!'
+        end
+      end
+    end
+
     # raises a hash error
     class ErrorHashApp
       class << self
@@ -68,20 +77,35 @@ def app
   end
 
   context 'with rescue_all' do
-    subject do
-      Rack::Builder.app do
-        use Spec::Support::EndpointFaker
-        use Grape::Middleware::Error, rescue_all: true
-        run ExceptionSpec::ExceptionApp
+    context 'StandardError exception' do
+      subject do
+        Rack::Builder.app do
+          use Spec::Support::EndpointFaker
+          use Grape::Middleware::Error, rescue_all: true
+          run ExceptionSpec::ExceptionApp
+        end
+      end
+      it 'sets the message appropriately' do
+        get '/'
+        expect(last_response.body).to eq('rain!')
+      end
+      it 'defaults to a 500 status' do
+        get '/'
+        expect(last_response.status).to eq(500)
       end
     end
-    it 'sets the message appropriately' do
-      get '/'
-      expect(last_response.body).to eq('rain!')
-    end
-    it 'defaults to a 500 status' do
-      get '/'
-      expect(last_response.status).to eq(500)
+
+    context 'Non-StandardError exception' do
+      subject do
+        Rack::Builder.app do
+          use Spec::Support::EndpointFaker
+          use Grape::Middleware::Error, rescue_all: true
+          run ExceptionSpec::OtherExceptionApp
+        end
+      end
+      it 'does not trap errors other than StandardError' do
+        expect { get '/' }.to raise_error(NotImplementedError, 'snow!')
+      end
     end
   end