(GH-50) Add document formatter for puppet-lint

Previously the vscode extension ran puppet-lint locally for fix linting issues,
however with the language server this feature was lost.  This commit adds the
document formatting feature back into the vscode extension;

* Uses the puppet-lint --fix feature to actually apply the fixes
* Adds a custom command to the language protocol puppet/fixDiagnosticErrors
  which will return a 'fixed' document and the number of fixes applied
* Adds an additional configuration option puppet.format.enable which will
  disable document formatting.

lib/languageserver/languageserver.rb

@@ -1,4 +1,4 @@
-%w[constants diagnostic completion_list completion_item hover location puppet_version puppet_compilation].each do |lib|
+%w[constants diagnostic completion_list completion_item hover location puppet_version puppet_compilation puppet_fix_diagnostic_errors].each do |lib|
   begin
     require "languageserver/#{lib}"
   rescue LoadError

lib/languageserver/puppet_fix_diagnostic_errors.rb

@@ -0,0 +1,39 @@
+module LanguageServer
+  module PuppetFixDiagnosticErrorsRequest
+    # export interface PuppetFixDiagnosticErrorsRequestParams {
+    #   documentUri: string;
+    #   alwaysReturnContent: boolean;
+    # }
+
+    def self.create(options)
+      result = {
+        'alwaysReturnContent' => false
+      }
+      raise('documentUri is a required field for PuppetFixDiagnosticErrorsRequest') if options['documentUri'].nil?
+
+      result['documentUri'] = options['documentUri']
+      result['alwaysReturnContent'] = options['alwaysReturnContent'] unless options['alwaysReturnContent'].nil?
+      result
+    end
+  end
+
+  module PuppetFixDiagnosticErrorsResponse
+    # export interface PuppetFixDiagnosticErrorsResponse {
+    #   documentUri: string;
+    #   fixesApplied: number;
+    #   newContent?: string;
+    # }
+
+    def self.create(options)
+      result = {}
+      raise('documentUri is a required field for PuppetFixDiagnosticErrorsResponse') if options['documentUri'].nil?
+      raise('fixesApplied is a required field for PuppetFixDiagnosticErrorsResponse') if options['fixesApplied'].nil?
+
+      result['documentUri']  = options['documentUri']
+      result['fixesApplied'] = options['fixesApplied']
+      result['newContent']   = options['newContent'] unless options['newContent'].nil?
+
+      result
+    end
+  end
+end

lib/puppet-languageserver/document_validator.rb

@@ -24,6 +24,33 @@ def self.find_module_root_from_path(path)
       module_root
     end
 
+    # Similar to 'validate' this will run puppet-lint and returns
+    # the manifest with any fixes applied
+    #
+    # Returns:
+    #  [ <Int> Number of problems fixed,
+    #    <String> New Content
+    #  ]
+    def self.fix_validate_errors(content, workspace)
+      # Find module root and attempt to build PuppetLint options
+      module_root = find_module_root_from_path(workspace)
+      linter_options = nil
+      if module_root.nil?
+        linter_options = PuppetLint::OptParser.build
+      else
+        Dir.chdir(module_root.to_s) { linter_options = PuppetLint::OptParser.build }
+      end
+      linter_options.parse!(['--fix'])
+
+      linter = PuppetLint::Checks.new
+      linter.load_data(nil, content)
+
+      problems = linter.run(nil, content)
+      problems_fixed = problems.nil? ? 0 : problems.count { |item| item[:kind] == :fixed }
+
+      [problems_fixed, linter.manifest]
+    end
+
     def self.validate(content, workspace, _max_problems = 100)
       result = []
       # TODO: Need to implement max_problems

lib/puppet-languageserver/message_router.rb

@@ -153,6 +153,30 @@ def receive_request(request)
         request.reply_result(LanguageServer::PuppetCompilation.create('dotContent' => dot_content,
                                                                       'error' => error_content))
 
+      when 'puppet/fixDiagnosticErrors'
+        begin
+          formatted_request = LanguageServer::PuppetFixDiagnosticErrorsRequest.create(request.params)
+          file_uri = formatted_request['documentUri']
+          content = documents.document(file_uri)
+
+          changes, new_content = PuppetLanguageServer::DocumentValidator.fix_validate_errors(content, @workspace)
+
+          request.reply_result(LanguageServer::PuppetFixDiagnosticErrorsResponse.create(
+                                 'documentUri'  => formatted_request['documentUri'],
+                                 'fixesApplied' => changes,
+                                 'newContent'   => changes > 0 || formatted_request['alwaysReturnContent'] ? new_content : nil
+          ))
+        rescue StandardError => exception
+          PuppetLanguageServer.log_message(:error, "(puppet/fixDiagnosticErrors) #{exception}")
+          unless formatted_request.nil?
+            request.reply_result(LanguageServer::PuppetFixDiagnosticErrorsResponse.create(
+                                   'documentUri'  => formatted_request['documentUri'],
+                                   'fixesApplied' => 0,
+                                   'newContent'   => formatted_request['alwaysReturnContent'] ? content : nil # rubocop:disable Metrics/BlockNesting
+            ))
+          end
+        end
+
       when 'textDocument/completion'
         file_uri = request.params['textDocument']['uri']
         line_num = request.params['position']['line']

spec/languageserver/integration/puppet-languageserver/document_validator_spec.rb

@@ -3,6 +3,102 @@
 describe 'document_validator' do
   let(:subject) { PuppetLanguageServer::DocumentValidator }
 
+  describe '#fix_validate_errors' do
+    describe "Given an incomplete manifest which has syntax errors but no lint errors" do
+      let(:manifest) { 'user { \'Bob\'' }
+
+      it "should return no changes" do
+        problems_fixed, new_content = subject.fix_validate_errors(manifest, nil)
+        expect(problems_fixed).to eq(0)
+        expect(new_content).to eq(manifest)
+      end
+    end
+
+    describe "Given a complete manifest which has a single fixable lint errors" do
+      let(:manifest) { "
+        user { \"Bob\":
+          ensure => 'present'
+        }"
+      }
+      let(:new_manifest) { "
+        user { 'Bob':
+          ensure => 'present'
+        }"
+      }
+
+      it "should return changes" do
+        problems_fixed, new_content = subject.fix_validate_errors(manifest, nil)
+        expect(problems_fixed).to eq(1)
+        expect(new_content).to eq(new_manifest)
+      end
+    end
+
+    describe "Given a complete manifest which has multiple fixable lint errors" do
+      let(:manifest) { "
+        // bad comment
+        user { \"Bob\":
+          name => 'username',
+          ensure => 'present'
+        }"
+      }
+      let(:new_manifest) { "
+        # bad comment
+        user { 'Bob':
+          name   => 'username',
+          ensure => 'present'
+        }"
+      }
+
+      it "should return changes" do
+        problems_fixed, new_content = subject.fix_validate_errors(manifest, nil)
+        expect(problems_fixed).to eq(3)
+        expect(new_content).to eq(new_manifest)
+      end
+    end
+
+
+    describe "Given a complete manifest which has unfixable lint errors" do
+      let(:manifest) { "
+        user { 'Bob':
+          name   => 'name',
+          ensure => 'present'
+        }"
+      }
+
+      it "should return no changes" do
+        problems_fixed, new_content = subject.fix_validate_errors(manifest, nil)
+        expect(problems_fixed).to eq(0)
+        expect(new_content).to eq(manifest)
+      end
+    end
+
+    describe "Given a complete manifest with CRLF which has fixable lint errors" do
+      let(:manifest)     { "user { \"Bob\":\r\nensure  => 'present'\r\n}" }
+      let(:new_manifest) { "user { 'Bob':\r\nensure  => 'present'\r\n}" }
+
+      it "should preserve CRLF" do
+        pending('Release of https://github.com/rodjek/puppet-lint/commit/2a850ab3fd3694a4dd0c4d2f22a1e60b9ca0a495')
+        problems_fixed, new_content = subject.fix_validate_errors(manifest, nil)
+        expect(problems_fixed).to eq(1)
+        expect(new_content).to eq(new_manifest)
+      end
+    end
+
+    describe "Given a complete manifest which has disabed fixable lint errors" do
+      let(:manifest) { "
+        user { \"Bob\": # lint:ignore:double_quoted_strings
+          ensure  => 'present'
+        }"
+      }
+
+      it "should return no changes" do
+        problems_fixed, new_content = subject.fix_validate_errors(manifest, nil)
+        expect(problems_fixed).to eq(0)
+        expect(new_content).to eq(manifest)
+      end
+    end
+  end
+
   describe '#validate' do
     describe "Given an incomplete manifest which has syntax errors" do
       let(:manifest) { 'user { "Bob"' }