Improve error message

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 0.1.3
+
+  * Improve error message a bit
+
 # 0.1.2
 
   * Error in mapped attribute raises `Scrapework::MappingError`

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    scrapework (0.1.2)
+    scrapework (0.1.3)
       active_attr
       activesupport
       nokogiri
@@ -27,7 +27,7 @@ GEM
     jaro_winkler (1.5.2)
     mini_portile2 (2.4.0)
     minitest (5.11.3)
-    nokogiri (1.10.3)
+    nokogiri (1.10.2)
       mini_portile2 (~> 2.4.0)
     parallel (1.17.0)
     parser (2.6.2.1)

lib/scrapework/object.rb

@@ -7,6 +7,7 @@
 
 module Scrapework
   # Base class for web data type
+  # rubocop:disable Metrics/ClassLength
   class Object
     include ActiveAttr::Model
 
@@ -17,6 +18,7 @@ def self.reflections
     end
 
     # rubocop:disable Metrics/MethodLength
+    # rubocop:disable Metrics/AbcSize
     def self.belongs_to(object, options = {})
       ivar = "@#{object}"
       mapped_method = "_mapped_#{object}"
@@ -36,6 +38,7 @@ def self.belongs_to(object, options = {})
 
       reflections[object] = { type: 'belongs_to', class: reflection_class }
     end
+    # rubocop:enable Metrics/AbcSize
     # rubocop:enable Metrics/MethodLength
 
     # rubocop:disable Naming/PredicateName
@@ -101,6 +104,8 @@ def self.has_one(object, options = {})
     # rubocop:enable Metrics/MethodLength
     # rubocop:enable Metrics/AbcSize
 
+    # rubocop:disable Metrics/AbcSize
+    # rubocop:disable Metrics/MethodLength
     def self.paginate(&block)
       mapped_method = :_pagination
 
@@ -118,6 +123,8 @@ def self.paginate(&block)
         self.class.new(pages[1]) if pages[1]
       end
     end
+    # rubocop:enable Metrics/MethodLength
+    # rubocop:enable Metrics/AbcSize
 
     def self.map(name, &block)
       mapped_method = :"_mapped_#{name}"
@@ -126,7 +133,7 @@ def self.map(name, &block)
         value = begin
                   instance_exec(_document, &block)
                 rescue StandardError => e
-                  raise MappingError, e.message
+                  raise MappingError, "failed to scrape `#{name}`: #{e.message}"
                 end
 
         public_send("#{name}=", value)
@@ -156,3 +163,4 @@ def load
     end
   end
 end
+# rubocop:enable Metrics/ClassLength

lib/scrapework/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Scrapework
-  VERSION = '0.1.2'
+  VERSION = '0.1.3'
 end