feat: introduce better error for wrong mime type (#805)

Now one can do:

    begin
      payload = HTTP.get("https://example.com").parse
    rescue HTTP::ParseError
      payload = {}
    end

Co-authored-by: Alexey Zapparov <alexey@zapparov.com>

Author: TheBlackArroVV

lib/http/errors.rb

@@ -32,6 +32,13 @@ def initialize(response)
     end
   end
 
+  # Raised when `Response#parse` fails due to any underlying reason (unexpected
+  # MIME type, or decoder fails). See `Exception#cause` for the original exception.
+  class ParseError < ResponseError; end
+
+  # Requested MimeType adapter not found.
+  class UnsupportedMimeTypeError < Error; end
+
   # Generic Timeout error
   class TimeoutError < Error; end
 

lib/http/mime_type.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "http/errors"
+
 module HTTP
   # MIME type encode/decode adapters
   module MimeType
@@ -35,7 +37,7 @@ def register_adapter(type, adapter)
       # @raise [Error] if no adapter found
       # @return [Class]
       def [](type)
-        adapters[normalize type] || raise(Error, "Unknown MIME type: #{type}")
+        adapters[normalize type] || raise(UnsupportedMimeTypeError, "Unknown MIME type: #{type}")
       end
 
       # Register a shortcut for MIME type

lib/http/response.rb

@@ -2,6 +2,7 @@
 
 require "forwardable"
 
+require "http/errors"
 require "http/headers"
 require "http/content_type"
 require "http/mime_type"
@@ -155,6 +156,8 @@ def chunked?
     # @return [Object]
     def parse(type = nil)
       MimeType[type || mime_type].decode to_s
+    rescue => e
+      raise ParseError, e.message
     end
 
     # Inspect a response

spec/lib/http/response_spec.rb

@@ -109,8 +109,8 @@
     context "with unknown content type" do
       let(:content_type) { "application/deadbeef" }
 
-      it "raises HTTP::Error" do
-        expect { response.parse }.to raise_error HTTP::Error
+      it "raises HTTP::ParseError" do
+        expect { response.parse }.to raise_error HTTP::ParseError
       end
     end
 
@@ -125,6 +125,15 @@
         expect(response.parse(:json)).to eq "foo" => "bar"
       end
     end
+
+    context "when underlying parser fails" do
+      let(:content_type) { "application/deadbeef" }
+      let(:body)         { "" }
+
+      it "raises HTTP::ParseError" do
+        expect { response.parse }.to raise_error HTTP::ParseError
+      end
+    end
   end
 
   describe "#flush" do