comment based type name generation

Author: tocsoft

Tocsoft.GraphQLCodeGen.Cli/IntrospectedSchemeParser.cs

@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using System.IO;
 
 namespace Tocsoft.GraphQLCodeGen
 {
@@ -81,8 +82,48 @@ public class LocatedNamedSource
             public string Path { get; set; }
             public string Body { get; set; }
             public int LineStartAt { get; internal set; }
-        }
 
+            private string[] lines;
+
+            public string Line(int line)
+            {
+                line = line - 1;
+                if (lines == null)
+                {
+
+                    lines = GetLines(Body).ToArray();
+                }
+
+                if (line < 0)
+                {
+                    return null;
+                }
+
+                if (line >= lines.Length)
+                {
+
+                    return null;
+                }
+
+                return lines[line];
+            }
+
+            private static IEnumerable<string> GetLines(string str, bool removeEmptyLines = false)
+            {
+                using (var sr = new StringReader(str))
+                {
+                    string line;
+                    while ((line = sr.ReadLine()) != null)
+                    {
+                        if (removeEmptyLines && String.IsNullOrWhiteSpace(line))
+                        {
+                            continue;
+                        }
+                        yield return line;
+                    }
+                }
+            }
+        }
     }
 
     public class NamedSource

Tocsoft.GraphQLCodeGen.Cli/ObjectModel/GraphQLDocument.cs

@@ -68,7 +68,7 @@ public GraphQLDocument(DocumentNode ast, IEnumerable<LocatedNamedSource> queryPa
             this.settings = settings;
             List<object> items = ast.Definitions.Select(this.Visit).ToList();
             this.Operations = items.OfType<Operation>().ToList();
-            this.types = items.OfType<IGraphQLType>().GroupBy(x=>x.Name).Select(x=>x.First()).ToList();
+            this.types = items.OfType<IGraphQLType>().GroupBy(x => x.Name).Select(x => x.First()).ToList();
             this.astPrinter = new AstPrinter(settings.TypeNameDirective);
             foreach (IGraphQLInitter i in items.OfType<IGraphQLInitter>().Where(x => !(x is Operation)))
             {
@@ -80,9 +80,45 @@ public GraphQLDocument(DocumentNode ast, IEnumerable<LocatedNamedSource> queryPa
             }
         }
 
-        internal IValueNode<string> ResolveSpecifiedTypeName(IEnumerable<DirectiveNode> directives)
+        internal IValueNode<string> ResolveSpecifiedTypeName(FieldNode field)
         {
-            var directive = directives.SingleOrDefault(x => x.Name.Value == this.settings.TypeNameDirective);
+            (LocatedNamedSource part, int offsetStart, int length) = ResolveNode(field.Location);
+
+            var allTextBeforeError = part.Body.Substring(0, offsetStart);
+            var lines = allTextBeforeError.Split('\n');
+            var line = lines.Count();
+
+            for (var i = line - 1; i > 0; i--)
+            {
+                // walk back looking to comment lines with a type name flag on it
+                var lineText = part.Line(i);
+                if (lineText == null)
+                {
+                    break;
+                }
+
+                lineText = lineText.Trim();
+                if (lineText.StartsWith("#!"))
+                {
+                    lineText = lineText.Substring(2);
+                    var p = lineText.Trim().Split(':').Select(x => x.Trim()).ToList();
+                    if (p[0].Equals("typename", StringComparison.OrdinalIgnoreCase) && p.Count > 1)
+                    {
+                        return new StringValueNode(p[1]);
+                    }
+                }
+                else if (lineText.StartsWith("\""))
+                {
+                    // skip as this is a description line
+                }
+                else if (lineText.Length != 0)
+                {
+                    // other lines stop looking as we have reached something else
+                    break;
+                }
+            }
+
+            var directive = field.Directives.SingleOrDefault(x => x.Name.Value == this.settings.TypeNameDirective);
             var value = directive?.Arguments.SingleOrDefault(x => x.Name.Value == "type")?.Value;
             var scalar = value as IValueNode<string>;
             return scalar;
@@ -244,12 +280,12 @@ private void UnPackType(ITypeNode type, ValueTypeReference target)
                 throw;
             }
         }
-      
+
         private object Visit(ISyntaxNode node)
         {
             switch (node)
             {
-                
+
                 case OperationDefinitionNode op:
                     return new Operation(op);
                 case InterfaceTypeDefinitionNode op:

Tocsoft.GraphQLCodeGen.Cli/ObjectModel/Selections/FieldSelection.cs

@@ -60,7 +60,7 @@ internal bool Resolve(GraphQLDocument doc, IGraphQLFieldCollection rootType)
             {
                 IGraphQLType root = this.Type.Type.Type as IGraphQLType;
 
-                var specifiedTypeName = doc.ResolveSpecifiedTypeName(this.op.Directives);
+                var specifiedTypeName = doc.ResolveSpecifiedTypeName(this.op);
                 this.Selection.Resolve(doc, root, specifiedTypeName);
             }
 

Tocsoft.GraphQLCodeGen.Tests/ClientOnlyDirectives.cs

@@ -58,6 +58,21 @@ public async Task TypeDirectiveCanChangeExportedTypeName()
             Assert.Single(generator.Model.Types.Select(x => x.Name), "TestResultABCD");
         }
 
+        [Fact]
+        public async Task CommentCanChangeExportedTypeName()
+        {
+            var settings = settingsLoader.GenerateSettings(new CodeGeneratorSettingsLoaderDefaults(), new[] { "./Files/ClientOnlyDirectives/QueryComment.gql" });
+
+            CodeGenerator generator = new CodeGenerator(logger, settings.Single());
+
+            await generator.LoadSource();
+            generator.Parse();
+
+            Assert.Empty(generator.Document.Errors);
+
+            Assert.Single(generator.Model.Types.Select(x => x.Name), "TestResultABCD");
+        }
+
         [Fact]
         public async Task ShouldRecieveErrorAboutTwoClassesWithSameName()
         {

Tocsoft.GraphQLCodeGen.Tests/Files/ClientOnlyDirectives/QueryComment.gql

@@ -0,0 +1,9 @@
+query q{
+    
+    #! typename: TestResultABCD
+    test(id: "safsa")
+	{
+        nullable,
+        nonnullable
+    }
+}