feat: support custom directives (#134)

Author: danadajian

src/annotations/build-directive-annotations.ts

@@ -17,6 +17,7 @@ import { ConstDirectiveNode } from "graphql/language";
 import { GraphQLSchema, isInputObjectType, Kind } from "graphql";
 import { shouldConsolidateTypes } from "../utils/should-consolidate-types";
 import { sanitizeName } from "../utils/sanitize-name";
+import { titleCase } from "../utils/title-case";
 
 export function buildDirectiveAnnotations(
   definitionNode: DefinitionNode,
@@ -50,17 +51,32 @@ export function buildDirectiveAnnotations(
           return !typeWillBeConsolidated;
         },
       );
-      if (!directiveReplacementFromConfig) return "";
-      const kotlinAnnotations = buildKotlinAnnotations(
-        directive,
-        directiveReplacementFromConfig.kotlinAnnotations,
+
+      if (directiveReplacementFromConfig) {
+        return (
+          buildKotlinAnnotationsFromConfig(
+            directive,
+            directiveReplacementFromConfig.kotlinAnnotations,
+          ).join("\n") + "\n"
+        );
+      }
+      const customDirectiveFromConfig = config.customDirectives?.find(
+        (directive) => directive === directiveName,
       );
-      return kotlinAnnotations.join("\n") + "\n";
+      if (customDirectiveFromConfig) {
+        return buildCustomDirective(directive);
+      }
+      return "";
     })
     .join("");
 }
 
-function buildKotlinAnnotations(
+function buildCustomDirective(directive: ConstDirectiveNode) {
+  const directiveName = directive.name.value;
+  return `@${titleCase(directiveName)}\n`;
+}
+
+function buildKotlinAnnotationsFromConfig(
   directive: ConstDirectiveNode,
   kotlinAnnotations: NonNullable<
     CodegenConfigWithDefaults["directiveReplacements"]

src/config/schema.ts

@@ -32,6 +32,16 @@ export const configSchema = object({
    * @link https://opensource.expediagroup.com/graphql-kotlin-codegen/docs/class-consolidation
    */
   classConsolidationEnabled: optional(boolean()),
+  /**
+   * Denotes directives to generate as @GraphQLDirective annotations.
+   *
+   * Directive arguments are not yet supported and will be ignored.
+   *
+   * @example ["myCustomDirective"]
+   *
+   * @link https://opensource.expediagroup.com/graphql-kotlin/docs/schema-generator/customizing-schemas/directives/#custom-directives
+   */
+  customDirectives: optional(array(string())),
   /**
    * Limits dependent types to include from `onlyTypes` list. Can be used to exclude classes that are imported from external packages.
    *

src/definitions/directive.ts

@@ -0,0 +1,33 @@
+/*
+Copyright 2024 Expedia, Inc.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    https://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { DirectiveDefinitionNode } from "graphql";
+import { CodegenConfigWithDefaults } from "../config/build-config-with-defaults";
+import { titleCase } from "../utils/title-case";
+
+export function buildDirectiveDefinition(
+  node: DirectiveDefinitionNode,
+  config: CodegenConfigWithDefaults,
+): string {
+  const directiveName = node.name.value;
+  const isCustomDirective = config.customDirectives?.includes(directiveName);
+  if (!isCustomDirective) {
+    return "";
+  }
+  return `@GraphQLDirective(
+    name = "${titleCase(directiveName)}",
+    description = "${node.description?.value ?? ""}",
+    locations = [${node.locations.map((location) => `graphql.introspection.Introspection.DirectiveLocation.${location.value}`).join(", ")}]
+)
+annotation class ${titleCase(directiveName)}`;
+}

src/visitor.ts

@@ -13,6 +13,7 @@ limitations under the License.
 
 import { BaseVisitor, RawConfig } from "@graphql-codegen/visitor-plugin-common";
 import {
+  DirectiveDefinitionNode,
   EnumTypeDefinitionNode,
   GraphQLSchema,
   InputObjectTypeDefinitionNode,
@@ -21,6 +22,7 @@ import {
   UnionTypeDefinitionNode,
 } from "graphql";
 import { CodegenConfigWithDefaults } from "./config/build-config-with-defaults";
+import { buildDirectiveDefinition } from "./definitions/directive";
 import { buildEnumTypeDefinition } from "./definitions/enum";
 import { buildInterfaceDefinition } from "./definitions/interface";
 import { buildInputObjectDefinition } from "./definitions/input";
@@ -39,6 +41,10 @@ export class KotlinVisitor extends BaseVisitor<
     super(rawConfig, rawConfig);
   }
 
+  DirectiveDefinition(node: DirectiveDefinitionNode): string {
+    return buildDirectiveDefinition(node, this.config);
+  }
+
   EnumTypeDefinition(node: EnumTypeDefinitionNode): string {
     return buildEnumTypeDefinition(node, this._schema, this.config);
   }

test/unit/should_generate_custom_directives/codegen.config.ts

@@ -0,0 +1,12 @@
+import { GraphQLKotlinCodegenConfig } from "../../../src/plugin";
+
+export default {
+  customDirectives: ["myCustomDirective", "myCustomDirective2"],
+  extraImports: ["should_honor_directiveReplacements_config.*"],
+  directiveReplacements: [
+    {
+      directive: "someDirective1",
+      kotlinAnnotations: ["@SomeAnnotation1"],
+    },
+  ],
+} satisfies GraphQLKotlinCodegenConfig;

test/unit/should_generate_custom_directives/expected.kt

@@ -0,0 +1,44 @@
+package com.kotlin.generated
+
+import com.expediagroup.graphql.generator.annotations.*
+import should_honor_directiveReplacements_config.*
+
+@GraphQLDirective(
+    name = "MyCustomDirective",
+    description = "A description for MyCustomDirective",
+    locations = [graphql.introspection.Introspection.DirectiveLocation.OBJECT, graphql.introspection.Introspection.DirectiveLocation.FIELD_DEFINITION, graphql.introspection.Introspection.DirectiveLocation.INPUT_OBJECT, graphql.introspection.Introspection.DirectiveLocation.INPUT_FIELD_DEFINITION]
+)
+annotation class MyCustomDirective
+
+@GraphQLDirective(
+    name = "MyCustomDirective2",
+    description = "",
+    locations = [graphql.introspection.Introspection.DirectiveLocation.OBJECT, graphql.introspection.Introspection.DirectiveLocation.FIELD_DEFINITION, graphql.introspection.Introspection.DirectiveLocation.INPUT_OBJECT, graphql.introspection.Introspection.DirectiveLocation.INPUT_FIELD_DEFINITION]
+)
+annotation class MyCustomDirective2
+
+@MyCustomDirective
+@MyCustomDirective2
+@SomeAnnotation1
+@GraphQLValidObjectLocations(locations = [GraphQLValidObjectLocations.Locations.OBJECT])
+data class MyTypeWithCustomDirectiveOnObject(
+    val field: String? = null
+)
+
+@GraphQLValidObjectLocations(locations = [GraphQLValidObjectLocations.Locations.OBJECT])
+data class MyTypeWithCustomDirectiveOnField(
+    @MyCustomDirective
+    val field: String? = null
+)
+
+@MyCustomDirective
+@GraphQLValidObjectLocations(locations = [GraphQLValidObjectLocations.Locations.INPUT_OBJECT])
+data class MyInputWithCustomDirectiveOnObject(
+    val field: String? = null
+)
+
+@GraphQLValidObjectLocations(locations = [GraphQLValidObjectLocations.Locations.INPUT_OBJECT])
+data class MyInputWithCustomDirectiveOnField(
+    @MyCustomDirective
+    val field: String? = null
+)

test/unit/should_generate_custom_directives/schema.graphql

@@ -0,0 +1,24 @@
+"A description for MyCustomDirective"
+directive @myCustomDirective on OBJECT | FIELD_DEFINITION | INPUT_OBJECT | INPUT_FIELD_DEFINITION
+directive @myCustomDirective2 on OBJECT | FIELD_DEFINITION | INPUT_OBJECT | INPUT_FIELD_DEFINITION
+
+directive @someDirective1 on OBJECT
+
+type MyTypeWithCustomDirectiveOnObject
+  @myCustomDirective
+  @myCustomDirective2
+  @someDirective1 {
+  field: String
+}
+
+type MyTypeWithCustomDirectiveOnField {
+  field: String @myCustomDirective
+}
+
+input MyInputWithCustomDirectiveOnObject @myCustomDirective {
+  field: String
+}
+
+input MyInputWithCustomDirectiveOnField {
+  field: String @myCustomDirective
+}