(GH-141) Update Completion and Hover providers for V4 API Functions

Now that the Sidecar and the Sidecar Protocol have been modified to emit V4
API function metadata the completion and hover providers need to be modified
to use it.  This commit:

* Because the concept of Function Type no longer exists (rvalue vs statement)
  all functions need to be returned when in the root of a document.  Therefore
  the all_statement_functions method is changed into all_functions
* The completion resolver is modified to only emit completion information if the
  function actually has a signature (all functions should have at least one
  sig). The resulting resolution now returns the function documentation and
  function signatures in separate fields in the response
* The insertion text for the completion item now just emits the function with
  empty parentheses. This should trigger the Signature Helper, which will be
  implemented in later commits
* The hover provider is modified to remove a todo item because arity no longer
  exists

Author: glennsarti

lib/puppet-languageserver/manifest/completion_provider.rb

@@ -24,8 +24,7 @@ def self.complete(content, line_num, char_num, options = {})
           # Add resources
           all_resources { |x| items << x }
 
-          # Find functions which don't return values i.e. statements
-          all_statement_functions { |x| items << x }
+          all_functions { |x| items << x }
 
           response = LSP::CompletionList.new
           response.items = items
@@ -170,9 +169,8 @@ def self.all_resources(&block)
         end
       end
 
-      def self.all_statement_functions(&block)
-        # Find functions which don't return values i.e. statements
-        PuppetLanguageServer::PuppetHelper.filtered_function_names { |_name, data| data.type == :statement }.each do |name|
+      def self.all_functions(&block)
+        PuppetLanguageServer::PuppetHelper.function_names.each do |name|
           item = LSP::CompletionItem.new(
             'label'  => name.to_s,
             'kind'   => LSP::CompletionItemKind::FUNCTION,
@@ -232,12 +230,12 @@ def self.resolve(completion_item)
           item_type = PuppetLanguageServer::PuppetHelper.function(data['name'])
           return result if item_type.nil?
           result.documentation = item_type.doc unless item_type.doc.nil?
-          result.insertText = "#{data['name']}(${1:value}"
-          (2..item_type.arity).each do |index|
-            result.insertText += ", ${#{index}:value}"
+          unless item_type.nil? || item_type.signatures.count.zero?
+            result.detail = item_type.signatures.map(&:key).join("\n\n")
+            # The signature provider should handle suggestions after this, so just place the cursor ready for an opening bracket
+            result.insertText = data['name'].to_s
+            result.insertTextFormat = LSP::InsertTextFormat::PLAINTEXT
           end
-          result.insertText += ')'
-          result.insertTextFormat = LSP::InsertTextFormat::SNIPPET
 
         when 'resource_type'
           item_type = PuppetLanguageServer::PuppetHelper.get_type(data['name'])

lib/puppet-languageserver/manifest/hover_provider.rb

@@ -142,8 +142,7 @@ def self.get_call_named_function_expression_content(item)
         func_info = PuppetLanguageServer::PuppetHelper.function(func_name)
         raise "Function #{func_name} does not exist" if func_info.nil?
 
-        # TODO: what about rvalue?
-        content = "**#{func_name}** Function" # TODO: Do I add in the params from the arity number?
+        content = "**#{func_name}** Function"
         content += "\n\n" + func_info.doc unless func_info.doc.nil?
 
         content

spec/languageserver/integration/puppet-languageserver/manifest/completion_provider_spec.rb

@@ -458,10 +458,10 @@ class Alice {
           expect(result.documentation).to match(/.+/)
         end
 
-        it 'should return a text snippet' do
+        it 'should return plain text' do
           result = subject.resolve(@resolve_request)
           expect(result.insertText).to match(/.+/)
-          expect(result.insertTextFormat).to eq(LSP::InsertTextFormat::SNIPPET)
+          expect(result.insertTextFormat).to eq(LSP::InsertTextFormat::PLAINTEXT)
         end
       end
     end