Add support for descriptions to all AST nodes according to the draft specification

src/GraphQLParser.ApiTests/ApiApprovalTests.Public_Api_Should_Not_Change_Inadvertently.approved.txt

@@ -47,6 +47,7 @@ namespace GraphQLParser.AST
         TypeExtensionDefinition = 35,
         DirectiveDefinition = 36,
         Comment = 37,
+        Description = 38,
     }
     public class GraphQLArgument : GraphQLParser.AST.ASTNode, GraphQLParser.AST.INamedNode
     {
@@ -61,6 +62,12 @@ namespace GraphQLParser.AST
         public override GraphQLParser.AST.ASTNodeKind Kind { get; }
         public string Text { get; set; }
     }
+    public class GraphQLDescription : GraphQLParser.AST.ASTNode
+    {
+        public GraphQLDescription(string value) { }
+        public override GraphQLParser.AST.ASTNodeKind Kind { get; }
+        public string Value { get; set; }
+    }
     public class GraphQLDirective : GraphQLParser.AST.ASTNode, GraphQLParser.AST.INamedNode
     {
         public GraphQLDirective() { }
@@ -207,7 +214,7 @@ namespace GraphQLParser.AST
         public GraphQLParser.AST.GraphQLName? Name { get; set; }
         public GraphQLParser.AST.GraphQLValue? Value { get; set; }
     }
-    public class GraphQLObjectTypeDefinition : GraphQLParser.AST.GraphQLTypeDefinition, GraphQLParser.AST.IHasDirectivesNode
+    public class GraphQLObjectTypeDefinition : GraphQLParser.AST.GraphQLTypeDefinition, GraphQLParser.AST.IHasDescriptionNode, GraphQLParser.AST.IHasDirectivesNode
     {
         public GraphQLObjectTypeDefinition() { }
         public System.Collections.Generic.List<GraphQLParser.AST.GraphQLDirective>? Directives { get; set; }
@@ -251,9 +258,10 @@ namespace GraphQLParser.AST
         public string? Value { get; set; }
         public override string? ToString() { }
     }
-    public class GraphQLSchemaDefinition : GraphQLParser.AST.ASTNode, GraphQLParser.AST.IHasDirectivesNode
+    public class GraphQLSchemaDefinition : GraphQLParser.AST.ASTNode, GraphQLParser.AST.IHasDescriptionNode, GraphQLParser.AST.IHasDirectivesNode
     {
         public GraphQLSchemaDefinition() { }
+        public GraphQLParser.AST.GraphQLDescription? Description { get; set; }
         public System.Collections.Generic.List<GraphQLParser.AST.GraphQLDirective>? Directives { get; set; }
         public override GraphQLParser.AST.ASTNodeKind Kind { get; }
         public System.Collections.Generic.List<GraphQLParser.AST.GraphQLOperationTypeDefinition>? OperationTypes { get; set; }
@@ -268,9 +276,10 @@ namespace GraphQLParser.AST
     {
         protected GraphQLType() { }
     }
-    public abstract class GraphQLTypeDefinition : GraphQLParser.AST.ASTNode, GraphQLParser.AST.INamedNode
+    public abstract class GraphQLTypeDefinition : GraphQLParser.AST.ASTNode, GraphQLParser.AST.IHasDescriptionNode, GraphQLParser.AST.INamedNode
     {
         protected GraphQLTypeDefinition() { }
+        public GraphQLParser.AST.GraphQLDescription? Description { get; set; }
         public GraphQLParser.AST.GraphQLName? Name { get; set; }
     }
     public class GraphQLTypeExtensionDefinition : GraphQLParser.AST.GraphQLTypeDefinition
@@ -304,6 +313,10 @@ namespace GraphQLParser.AST
         public GraphQLParser.AST.GraphQLType? Type { get; set; }
         public GraphQLParser.AST.GraphQLVariable? Variable { get; set; }
     }
+    public interface IHasDescriptionNode
+    {
+        GraphQLParser.AST.GraphQLDescription? Description { get; set; }
+    }
     public interface IHasDirectivesNode
     {
         System.Collections.Generic.List<GraphQLParser.AST.GraphQLDirective>? Directives { get; set; }

src/GraphQLParser.Tests/ParserTests.cs

@@ -530,5 +530,50 @@ public void Should_Parse_Unions(string text)
         {
             new Parser(new Lexer()).Parse(new Source(text)).ShouldNotBeNull();
         }
+
+        [Theory]
+        [InlineData("\"schema description\" schema { query : Query }", "schema description")]
+        [InlineData("\"scalar description\" scalar DateTime", "scalar description")]
+        [InlineData("\"type description\" type Query { name : String }", "type description")]
+        [InlineData("\"interface description\" interface Person { name : String }", "interface description")]
+        [InlineData("\"union description\" union Person = He | She", "union description")]
+        [InlineData("\"enum description\" enum Currency { EUR USD }", "enum description")]
+        [InlineData("\"input description\" input PersonInput { name : String }", "input description")]
+        [InlineData("\"directive description\" directive @example on FIELD", "directive description")]
+        public void Should_Parse_TypeDefinition_Description(string text, string expectedDescription)
+        {
+            var document = new Parser(new Lexer()).Parse(new Source(text));
+            ((IHasDescriptionNode)document.Definitions[0]).Description.Value.ShouldBe(expectedDescription);
+        }
+
+        [Fact]
+        public void Should_Parse_FieldDefinition_Description()
+        {
+            var text = "type Query { \"field description\" name : String }";
+            var document = new Parser(new Lexer()).Parse(new Source(text));
+            var objectTypeDefinition = document.Definitions.OfType<GraphQLObjectTypeDefinition>().First();
+            objectTypeDefinition.Fields[0].Description.Value.ShouldBe("field description");
+        }
+
+        [Fact]
+        public void Should_Parse_InputValueDefinition_Description()
+        {
+            var text = "type Query { name(\"input value description\" inputValue: Int) : String }";
+            var document = new Parser(new Lexer()).Parse(new Source(text));
+            var objectTypeDefinition = document.Definitions.OfType<GraphQLObjectTypeDefinition>().First();
+            objectTypeDefinition.Fields[0]
+                .Arguments[0].Description.Value.ShouldBe("input value description");
+        }
+
+        [Fact]
+        public void Should_Parse_EnumValueDefinition_Description()
+        {
+            var text = "enum Currency { \"EUR value description\" EUR \"USD value description\" USD }";
+            var document = new Parser(new Lexer()).Parse(new Source(text));
+            var enumTypeDefinition = document.Definitions.OfType<GraphQLEnumTypeDefinition>().First();
+            enumTypeDefinition.Values
+                .Select(v=>v.Description.Value)
+                .ShouldBe(new []{"EUR value description", "USD value description"});
+        }
     }
 }

src/GraphQLParser/AST/Enums.cs

@@ -40,6 +40,7 @@ public enum ASTNodeKind
         TypeExtensionDefinition,
         DirectiveDefinition,
         Comment,
+        Description
     }
 
     public enum OperationType
@@ -48,4 +49,4 @@ public enum OperationType
         Mutation,
         Subscription
     }
-}
+}

src/GraphQLParser/AST/GraphQLDescription.cs

@@ -0,0 +1,14 @@
+namespace GraphQLParser.AST
+{
+    public class GraphQLDescription : ASTNode
+    {
+        public GraphQLDescription(string value)
+        {
+            Value = value;
+        }
+
+        public override ASTNodeKind Kind => ASTNodeKind.Description;
+
+        public string Value { get; set; }
+    }
+}

src/GraphQLParser/AST/GraphQLObjectTypeDefinition.cs

@@ -2,7 +2,7 @@
 
 namespace GraphQLParser.AST
 {
-    public class GraphQLObjectTypeDefinition : GraphQLTypeDefinition, IHasDirectivesNode
+    public class GraphQLObjectTypeDefinition : GraphQLTypeDefinition, IHasDirectivesNode, IHasDescriptionNode
     {
         public List<GraphQLDirective>? Directives { get; set; }
 
@@ -12,4 +12,4 @@ public class GraphQLObjectTypeDefinition : GraphQLTypeDefinition, IHasDirectives
 
         public override ASTNodeKind Kind => ASTNodeKind.ObjectTypeDefinition;
     }
-}
+}

src/GraphQLParser/AST/GraphQLSchemaDefinition.cs

@@ -2,12 +2,14 @@
 
 namespace GraphQLParser.AST
 {
-    public class GraphQLSchemaDefinition : ASTNode, IHasDirectivesNode
+    public class GraphQLSchemaDefinition : ASTNode, IHasDirectivesNode, IHasDescriptionNode
     {
         public List<GraphQLDirective>? Directives { get; set; }
 
         public override ASTNodeKind Kind => ASTNodeKind.SchemaDefinition;
 
         public List<GraphQLOperationTypeDefinition>? OperationTypes { get; set; }
+
+        public GraphQLDescription? Description { get; set; }
     }
-}
+}

src/GraphQLParser/AST/GraphQLTypeDefinition.cs

@@ -1,7 +1,9 @@
 namespace GraphQLParser.AST
 {
-    public abstract class GraphQLTypeDefinition : ASTNode, INamedNode
+    public abstract class GraphQLTypeDefinition : ASTNode, INamedNode, IHasDescriptionNode
     {
         public GraphQLName? Name { get; set; }
+
+        public GraphQLDescription? Description { get; set; }
     }
-}
+}

src/GraphQLParser/AST/IHasDescriptionNode.cs

@@ -0,0 +1,7 @@
+namespace GraphQLParser.AST
+{
+    public interface IHasDescriptionNode
+    {
+        GraphQLDescription? Description { get; set; }
+    }
+}