Fix pronto hooks with warning level

lib/overcommit/hook/shared/pronto.rb

@@ -1,19 +1,23 @@
 # frozen_string_literal: true
 
 module Overcommit::Hook::Shared
-  # Shared code used by all Pronto hooks. Runs pronto linter.
+  # Shared code used by all Pronto hooks. Runs pronto linters.
+
+  # @see https://github.com/prontolabs/pronto
   module Pronto
     MESSAGE_TYPE_CATEGORIZER = lambda do |type|
       type.include?('E') ? :error : :warning
     end
 
+    MESSAGE_REGEX = /^(?<file>(?:\w:)?[^:]+):(?<line>\d+) (?<type>[^ ]+)/.freeze
+
     def run
       result = execute(command)
       return :pass if result.success?
 
       extract_messages(
-        result.stdout.split("\n"),
-        /^(?<file>(?:\w:)?[^:]+):(?<line>\d+) (?<type>[^ ]+)/,
+        result.stdout.split("\n").select { |line| line.match?(MESSAGE_REGEX) },
+        MESSAGE_REGEX,
         MESSAGE_TYPE_CATEGORIZER,
       )
     end

spec/overcommit/hook/pre_commit/pronto_spec.rb

@@ -41,10 +41,15 @@
 
     context 'and it reports a warning' do
       before do
-        result.stub(:stdout).and_return([
-          'file1.rb:12 W: Line is too long. [107/80]',
-          'file2.rb:14 I: Prefer single-quoted strings'
-        ].join("\n"))
+        result.stub(:stdout).and_return <<~MESSAGE
+          Running Pronto::Rubocop
+          file1.rb:12 W: Line is too long. [107/80]
+          file2.rb:14 I: Prefer single-quoted strings
+
+          ```suggestion
+          x = 'x'
+          ```
+        MESSAGE
       end
 
       it { should warn }

spec/overcommit/hook/pre_push/pronto_spec.rb

@@ -41,10 +41,15 @@
 
     context 'and it reports a warning' do
       before do
-        result.stub(:stdout).and_return([
-          'file1.rb:12 W: Line is too long. [107/80]',
-          'file2.rb:14 I: Prefer single-quoted strings'
-        ].join("\n"))
+        result.stub(:stdout).and_return <<~MESSAGE
+          Running Pronto::Rubocop
+          file1.rb:12 W: Line is too long. [107/80]
+          file2.rb:14 I: Prefer single-quoted strings
+
+          ```suggestion
+          x = 'x'
+          ```
+        MESSAGE
       end
 
       it { should warn }