Extract Out PreCommit Message Methods to Utils

lib/overcommit/hook/pre_commit/base.rb

@@ -1,4 +1,5 @@
 require 'forwardable'
+require 'overcommit/utils/messages_utils'
 
 module Overcommit::Hook::PreCommit
   # Functionality common to all pre-commit hooks.
@@ -9,71 +10,8 @@ class Base < Overcommit::Hook::Base
 
     private
 
-    # Extract file, line number, and type of message from an error/warning
-    # messages in output.
-    #
-    # Assumes each element of `output` is a separate error/warning with all
-    # information necessary to identify it.
-    #
-    # @param output_messages [Array<String>] unprocessed error/warning messages
-    # @param regex [Regexp] regular expression defining `file`, `line` and
-    #   `type` capture groups used to extract file locations and error/warning
-    #   type from each line of output
-    # @param type_categorizer [Proc] function executed against the `type`
-    #   capture group to convert it to a `:warning` or `:error` symbol. Assumes
-    #   `:error` if `nil`.
-    # @raise [Overcommit::Exceptions::MessageProcessingError] line of output did
-    #   not match regex
-    # @return [Array<Message>]
-    def extract_messages(output_messages, regex, type_categorizer = nil)
-      output_messages.map.with_index do |message, index|
-        unless match = message.match(regex)
-          raise Overcommit::Exceptions::MessageProcessingError,
-                'Unexpected output: unable to determine line number or type ' \
-                "of error/warning for output:\n" \
-                "#{output_messages[index..-1].join("\n")}"
-        end
-
-        file = extract_file(match, message)
-        line = extract_line(match, message) if match.names.include?('line') && match[:line]
-        type = extract_type(match, message, type_categorizer)
-
-        Overcommit::Hook::Message.new(type, file, line, message)
-      end
-    end
-
-    def extract_file(match, message)
-      return unless match.names.include?('file')
-
-      if match[:file].to_s.empty?
-        raise Overcommit::Exceptions::MessageProcessingError,
-              "Unexpected output: no file found in '#{message}'"
-      end
-
-      match[:file]
-    end
-
-    def extract_line(match, message)
-      return unless match.names.include?('line')
-      Integer(match[:line])
-    rescue ArgumentError, TypeError
-      raise Overcommit::Exceptions::MessageProcessingError,
-            "Unexpected output: invalid line number found in '#{message}'"
-    end
-
-    def extract_type(match, message, type_categorizer)
-      if type_categorizer
-        type_match = match.names.include?('type') ? match[:type] : nil
-        type = type_categorizer.call(type_match)
-        unless Overcommit::Hook::MESSAGE_TYPES.include?(type)
-          raise Overcommit::Exceptions::MessageProcessingError,
-                "Invalid message type '#{type}' for '#{message}': must " \
-                "be one of #{Overcommit::Hook::MESSAGE_TYPES.inspect}"
-        end
-        type
-      else
-        :error # Assume error since no categorizer was defined
-      end
+    def extract_messages(*args)
+      Overcommit::Utils::MessagesUtils.extract_messages(*args)
     end
   end
 end

lib/overcommit/utils/messages_utils.rb

@@ -0,0 +1,75 @@
+module Overcommit::Utils
+  # Utility to process messages
+  module MessagesUtils
+    class << self
+      # Extract file, line number, and type of message from an error/warning
+      # messages in output.
+      #
+      # Assumes each element of `output` is a separate error/warning with all
+      # information necessary to identify it.
+      #
+      # @param output_messages [Array<String>] unprocessed error/warning messages
+      # @param regex [Regexp] regular expression defining `file`, `line` and
+      #   `type` capture groups used to extract file locations and error/warning
+      #   type from each line of output
+      # @param type_categorizer [Proc] function executed against the `type`
+      #   capture group to convert it to a `:warning` or `:error` symbol. Assumes
+      #   `:error` if `nil`.
+      # @raise [Overcommit::Exceptions::MessageProcessingError] line of output did
+      #   not match regex
+      # @return [Array<Message>]
+      def extract_messages(output_messages, regex, type_categorizer = nil)
+        output_messages.map.with_index do |message, index|
+          unless match = message.match(regex)
+            raise Overcommit::Exceptions::MessageProcessingError,
+                  'Unexpected output: unable to determine line number or type ' \
+                  "of error/warning for output:\n" \
+                  "#{output_messages[index..-1].join("\n")}"
+          end
+
+          file = extract_file(match, message)
+          line = extract_line(match, message) if match.names.include?('line') && match[:line]
+          type = extract_type(match, message, type_categorizer)
+
+          Overcommit::Hook::Message.new(type, file, line, message)
+        end
+      end
+
+      private
+
+      def extract_file(match, message)
+        return unless match.names.include?('file')
+
+        if match[:file].to_s.empty?
+          raise Overcommit::Exceptions::MessageProcessingError,
+                "Unexpected output: no file found in '#{message}'"
+        end
+
+        match[:file]
+      end
+
+      def extract_line(match, message)
+        return unless match.names.include?('line')
+        Integer(match[:line])
+      rescue ArgumentError, TypeError
+        raise Overcommit::Exceptions::MessageProcessingError,
+              "Unexpected output: invalid line number found in '#{message}'"
+      end
+
+      def extract_type(match, message, type_categorizer)
+        if type_categorizer
+          type_match = match.names.include?('type') ? match[:type] : nil
+          type = type_categorizer.call(type_match)
+          unless Overcommit::Hook::MESSAGE_TYPES.include?(type)
+            raise Overcommit::Exceptions::MessageProcessingError,
+                  "Invalid message type '#{type}' for '#{message}': must " \
+                  "be one of #{Overcommit::Hook::MESSAGE_TYPES.inspect}"
+          end
+          type
+        else
+          :error # Assume error since no categorizer was defined
+        end
+      end
+    end
+  end
+end