(#240) Fix output of default values that are expressions

Previously, parameters with a default value that was an expression were
not outputted into the documentation correctly. For example,

    Integer $param = 1 + 1,

Would be shown in the documentation to have a default value of “+”.

This switches to using `extract_tree_text` instead of `extract_text` to
get the text representation of the parsed Puppet code.

This also gets rid of the dependency on
`Puppet::Pops::Adapters::SourcePosAdapter`, which was [deprecated in
2017](puppetlabs/puppet@68498ad).

Unfortunately, it appears that there is a bug in Puppet ([PUP-11632][])
that sometimes returns the incorrect default value. This adds two
skipped tests that demonstrate the issue.

[PUP-11632]: https://tickets.puppetlabs.com/browse/PUP-11632

lib/puppet-strings/yard/handlers/ruby/data_type_handler.rb

@@ -152,12 +152,12 @@ def literal_Object(o)
 
     def literal_AccessExpression(o)
       # Extract the raw text of the Access Expression
-      ::Puppet::Pops::Adapters::SourcePosAdapter.adapt(o).extract_text
+      PuppetStrings::Yard::Util.ast_to_text(o)
     end
 
     def literal_QualifiedReference(o)
       # Extract the raw text of the Qualified Reference
-      ::Puppet::Pops::Adapters::SourcePosAdapter.adapt(o).extract_text
+      PuppetStrings::Yard::Util.ast_to_text(o)
     end
 
     # ----- The following methods are the same as the original Literal_evaluator

lib/puppet-strings/yard/parsers/puppet/statement.rb

@@ -21,9 +21,8 @@ class Statement
     def initialize(object, file)
       @file = file
 
-      adapter = ::Puppet::Pops::Adapters::SourcePosAdapter.adapt(object)
-      @source = adapter.extract_text
-      @line = adapter.line
+      @source = PuppetStrings::Yard::Util.ast_to_text(object)
+      @line = object.line
       @comments_range = nil
     end
 
@@ -86,13 +85,11 @@ def initialize(parameter)
         @name = parameter.name
         # Take the exact text for the type expression
         if parameter.type_expr
-          adapter = ::Puppet::Pops::Adapters::SourcePosAdapter.adapt(parameter.type_expr)
-          @type = adapter.extract_text
+          @type = PuppetStrings::Yard::Util.ast_to_text(parameter.type_expr)
         end
         # Take the exact text for the default value expression
         return unless parameter.value
-        adapter = ::Puppet::Pops::Adapters::SourcePosAdapter.adapt(parameter.value)
-        @value = adapter.extract_text
+        @value = PuppetStrings::Yard::Util.ast_to_text(parameter.value)
       end
     end
 
@@ -149,8 +146,7 @@ def initialize(object, file)
       return unless object.respond_to? :return_type
       type = object.return_type
       return unless type
-      adapter = ::Puppet::Pops::Adapters::SourcePosAdapter.adapt(type)
-      @type = adapter.extract_text.gsub('>> ', '')
+      @type = PuppetStrings::Yard::Util.ast_to_text(type).gsub('>> ', '')
     end
   end
 
@@ -182,12 +178,11 @@ def initialize(object, file)
       case type_expr
       when Puppet::Pops::Model::AccessExpression
         # TODO: I don't like rebuilding the source from the AST, but AccessExpressions don't expose the original source
-        @alias_of = ::Puppet::Pops::Adapters::SourcePosAdapter.adapt(type_expr.left_expr).extract_text + '['
-        @alias_of << type_expr.keys.map { |key| ::Puppet::Pops::Adapters::SourcePosAdapter.adapt(key).extract_text }.join(', ')
+        @alias_of = PuppetStrings::Yard::Util.ast_to_text(type_expr.left_expr) + '['
+        @alias_of << type_expr.keys.map { |key| PuppetStrings::Yard::Util.ast_to_text(key) }.join(', ')
         @alias_of << ']'
       else
-        adapter = ::Puppet::Pops::Adapters::SourcePosAdapter.adapt(type_expr)
-        @alias_of = adapter.extract_text
+        @alias_of = PuppetStrings::Yard::Util.ast_to_text(type_expr)
       end
       @name = object.name
     end

lib/puppet-strings/yard/util.rb

@@ -79,4 +79,11 @@ def self.docstring_to_hash(docstring, select_tags = nil)
 
     hash
   end
+
+  # Convert Puppet AST to text.
+  # @param [Puppet::Pops::Model::PopsObject] ast The Puppet AST to convert to text.
+  # @return [String] Returns a string of Puppet code.
+  def self.ast_to_text(ast)
+    ast.locator.extract_tree_text(ast)
+  end
 end

spec/unit/puppet-strings/yard/parsers/puppet/parser_spec.rb

@@ -260,4 +260,63 @@ class bar {
       end
     end
   end
+
+  [
+    'undef',
+    'true',
+    '-1',
+    '0.34',
+    'bareword',
+    "'single quotes'",
+    '"double quotes"',
+    '[]',
+    '[1]',
+    '{}',
+    '{ a => 1 }',
+    '$param1',
+    '1 + 1',
+    'func()',
+    '$param1.foo(1)',
+    '$param1.foo($param2 + $param3.bar())',
+  ].each do |value|
+    describe "parsing parameter with #{value} default value" do
+      let(:source) { <<~PUPPET }
+        class foo (
+          $param1 = #{value},
+        ) {}
+      PUPPET
+
+      it 'finds correct value' do
+        spec_subject.parse
+        statement = spec_subject.enumerator.first
+        expect(statement.parameters.size).to eq(1)
+        expect(statement.parameters[0].value).to eq(value)
+      end
+    end
+  end
+
+  [
+    '$param1.foo()',
+    "$facts['kernel'] ? {
+        'Linux'  => 'linux',
+        'Darwin' => 'darwin',
+        default  => $facts['kernel'],
+      }",
+  ].each do |value|
+    describe "parsing parameter with #{value} default value" do
+      let(:source) { <<~PUPPET }
+        class foo (
+          $param1 = #{value},
+        ) {}
+      PUPPET
+
+      it 'finds correct value' do
+        skip('Broken by https://tickets.puppetlabs.com/browse/PUP-11632')
+        spec_subject.parse
+        statement = spec_subject.enumerator.first
+        expect(statement.parameters.size).to eq(1)
+        expect(statement.parameters[0].value).to eq(value)
+      end
+    end
+  end
 end

spec/unit/puppet-strings/yard/util_spec.rb

@@ -47,4 +47,11 @@
       expect(spec_subject.github_to_yard_links(str)).to eq('<a href="#label-Module+description"> module-description')
     end
   end
+
+  describe 'ast_to_text' do
+    it 'converts a simple AST correctly' do
+      model = Puppet::Pops::Parser::Parser.new.parse_string('class test {}').model
+      expect(described_class.ast_to_text(model.body)).to eq('class test {}')
+    end
+  end
 end