feat: add schema and define schemas for GraphQL integration

Author: productdevbook

playground/package.json

@@ -7,7 +7,8 @@
     "preview": "node .output/server/index.mjs"
   },
   "dependencies": {
-    "nitro-graphql": "link:../"
+    "nitro-graphql": "link:../",
+    "zod": "^4.0.5"
   },
   "devDependencies": {
     "nitropack": "^2.11.13"

playground/server/graphql/schemas.ts

@@ -0,0 +1,8 @@
+import type { SchemaType } from '#graphql/server'
+import { z } from 'zod/v4'
+
+export const schemas: SchemaType = {
+  Todo: z.object({
+    id: z.string(),
+  }),
+}

playground/server/graphql/todos/todo-queries.resolver.ts

@@ -4,9 +4,6 @@ export default defineResolver({
       // const todos = await storage.getItem('todos') || []
       return [{
         id: '1',
-        title: 'Sample Todo',
-        completed: false,
-        createdAt: new Date().toISOString(),
       }]
     },
 

pnpm-lock.yaml

@@ -60,10 +60,14 @@ export async function generateTypes(
     contextType: 'h3#H3Event',
     maybeValue: 'T | null | undefined',
     inputMaybeValue: 'T | undefined',
-    enumsAsTypes: true,
-    useTypeImports: true,
+    declarationKind: 'interface',
+    allowParentTypeOverride: false,
+    // Type safety maximization
     strictScalars: true,
-    emitLegacyCommonJSImports: false,
+    // Modern TypeScript support
+    useTypeImports: true,
+    enumsAsTypes: true,
+    immutableTypes: true,
   }
 
   const mergedConfig = defu(config, defaultConfig)
@@ -84,38 +88,58 @@ export async function generateTypes(
         plugin: pluginContent,
       },
       imports: {
-        plugin: () => ({
-          prepend: [
-            `type Primitive =
-    | null
-    | undefined
-    | string
-    | number
-    | boolean
-    | symbol
-    | bigint;
+        plugin: () => {
+          return {
+            prepend: [
+              `import { schemas } from '#graphql/schemas'`,
+              `import type { StandardSchemaV1 } from 'nitro-graphql'`,
+
+              `
+export type SchemaType = Partial<Record<Partial<keyof ResolversTypes>, StandardSchemaV1>>
+type SchemaKeys = keyof typeof schemas;
+
+type InferInput<T> = T extends StandardSchemaV1 ? StandardSchemaV1.InferInput<T> : unknown;
+type InferOutput<T> = T extends StandardSchemaV1 ? StandardSchemaV1.InferOutput<T> : unknown;
+
+type InferInputFromSchema<T extends SchemaKeys> = InferInput<(typeof schemas)[T]>;
+type InferOutputFromSchema<T extends SchemaKeys> = InferOutput<(typeof schemas)[T]>;
+
+type Primitive =
+| null
+| undefined
+| string
+| number
+| boolean
+| symbol
+| bigint;
 
 type BuiltIns = Primitive | void | Date | RegExp;
 
+
 type ResolverReturnType<T> = T extends BuiltIns
-    ? T
-    : T extends (...args: any[]) => unknown
-    ? T | undefined
-    : T extends object
-    ? T extends Array<infer ItemType> // Test for arrays/tuples, per https://github.com/microsoft/TypeScript/issues/35156
-        ? ItemType[] extends T // Test for arrays (non-tuples) specifically
-            ? Array<ResolverReturnType<ItemType>>
-            : ResolverReturnTypeObject<T> // Tuples behave properly
-        : ResolverReturnTypeObject<T>
-    : unknown;
+? T
+: T extends (...args: any[]) => unknown
+? T | undefined
+: T extends object
+? T extends Array<infer ItemType> // Test for arrays/tuples, per https://github.com/microsoft/TypeScript/issues/35156
+  ? ItemType[] extends T // Test for arrays (non-tuples) specifically
+    ? Array<ResolverReturnType<ItemType>>
+    : ResolverReturnTypeObject<T> // Tuples behave properly
+  : ResolverReturnTypeObject<T>
+: unknown;
 
-type ResolverReturnTypeObject<T extends object> = {
-  [K in keyof T]: ResolverReturnType<T[K]>
-};`,
-            '',
-          ],
-          content: '',
-        }),
+type ResolverReturnTypeObject<T extends object> =
+  T extends { __typename?: infer TTypename }
+    ? TTypename extends SchemaKeys
+      ? InferOutputFromSchema<TTypename>
+      : { [K in keyof T]: ResolverReturnType<T[K]> }
+    : { [K in keyof T]: ResolverReturnType<T[K]> };
+`,
+              '',
+            ],
+            content: '',
+          }
+        },
       },
       typescript: typescriptPlugin,
       typescriptResolvers: typescriptResolversPlugin,

src/codegen.ts

@@ -181,6 +181,7 @@ declare module 'nitro-graphql' {
 `
 
     writeFileSync(join(typesDir, 'graphql.d.ts'), graphqlDtsContent)
+    nitro.options.typescript.strict = true
 
     nitro.hooks.hook('types:extend', (types) => {
       // Add TypeScript path alias for IDE support
@@ -193,6 +194,9 @@ declare module 'nitro-graphql' {
       types.tsConfig.compilerOptions.paths['#graphql/client'] = [
         relativeWithDot(tsconfigDir, join(typesDir, 'nitro-graphql-client.d.ts')),
       ]
+      types.tsConfig.compilerOptions.paths['#graphql/schemas'] = [
+        relativeWithDot(tsconfigDir, join(nitro.graphql.serverDir, 'schemas.ts')),
+      ]
       types.tsConfig.include = types.tsConfig.include || []
       types.tsConfig.include.push(
         relativeWithDot(tsconfigDir, join(typesDir, 'nitro-graphql-server.d.ts')),