feat: allows for passthrough of a default/fallback scalar type

README.md

@@ -187,6 +187,26 @@ config:
     Email: z.string().email()
 ```
 
+### `defaultScalarTypeSchema`
+
+type: `string`
+
+Fallback scalar type for undefined scalar types in the schema not found in `scalarSchemas`.
+
+#### yup schema
+```yml
+config:
+  schema: yup
+  defaultScalarSchema: yup.unknown()
+```
+
+#### zod schema
+```yml
+config:
+  schema: zod
+  defaultScalarSchema: z.unknown()
+```
+
 ### `withObjectType`
 
 type: `boolean` default: `false`

src/config.ts

@@ -176,6 +176,24 @@ export interface ValidationSchemaPluginConfig extends TypeScriptPluginConfig {
    * ```
    */
   scalarSchemas?: ScalarSchemas
+  /**
+   * @description Fallback scalar type for undefined scalar types in the schema not found in `scalarSchemas`.
+   *
+   * @exampleMarkdown
+   * ```yml
+   * config:
+   *   schema: yup
+   *   defaultScalarSchema: yup.unknown()
+   * ```
+   *
+   * @exampleMarkdown
+   * ```yml
+   * config:
+   *   schema: zod
+   *   defaultScalarSchema: z.unknown()
+   * ```
+   */
+  defaultScalarTypeSchema?: string
   /**
    * @description Generates validation schema with GraphQL type objects.
    * but excludes "Query", "Mutation", "Subscription" objects.

src/myzod/index.ts

@@ -374,6 +374,11 @@ function myzod4Scalar(config: ValidationSchemaPluginConfig, visitor: Visitor, sc
     case 'boolean':
       return `myzod.boolean()`;
   }
+
+  if (config.defaultScalarTypeSchema) {
+    return config.defaultScalarTypeSchema;
+  }
+
   console.warn('unhandled name:', scalarName);
   return anySchema;
 }

src/valibot/index.ts

@@ -299,6 +299,11 @@ function valibot4Scalar(config: ValidationSchemaPluginConfig, visitor: Visitor,
     case 'boolean':
       return `v.boolean()`;
   }
+
+  if (config.defaultScalarTypeSchema) {
+    return config.defaultScalarTypeSchema;
+  }
+
   console.warn('unhandled scalar name:', scalarName);
   return 'v.any()';
 }

src/yup/index.ts

@@ -396,6 +396,11 @@ function yup4Scalar(config: ValidationSchemaPluginConfig, visitor: Visitor, scal
     case 'boolean':
       return `yup.boolean().defined()`;
   }
+
+  if (config.defaultScalarTypeSchema) {
+    return config.defaultScalarTypeSchema
+  }
+
   console.warn('unhandled name:', scalarName);
   return `yup.mixed()`;
 }

src/zod/index.ts

@@ -390,6 +390,11 @@ function zod4Scalar(config: ValidationSchemaPluginConfig, visitor: Visitor, scal
     case 'boolean':
       return `z.boolean()`;
   }
+
+  if (config.defaultScalarTypeSchema) {
+    return config.defaultScalarTypeSchema;
+  }
+
   console.warn('unhandled scalar name:', scalarName);
   return anySchema;
 }

tests/myzod.spec.ts

@@ -467,6 +467,41 @@ describe('myzod', () => {
       "
     `)
   });
+
+  it('with defaultScalarTypeSchema', async () => {
+    const schema = buildSchema(/* GraphQL */ `
+      input ScalarsInput {
+        date: Date!
+        email: Email
+        str: String!
+      }
+      scalar Date
+      scalar Email
+    `);
+    const result = await plugin(
+      schema,
+      [],
+      {
+        schema: 'myzod',
+        scalarSchemas: {
+          Email: 'myzod.string()', // generate the basic type. User can later extend it using `withPredicate(fn: (val: string) => boolean), errMsg?: string }`
+        },
+        defaultScalarTypeSchema: 'myzod.string()',
+      },
+      {},
+    );
+    expect(removedInitialEmitValue(result.content)).toMatchInlineSnapshot(`
+      "
+      export function ScalarsInputSchema(): myzod.Type<ScalarsInput> {
+        return myzod.object({
+          date: myzod.string(),
+          email: myzod.string().optional().nullable(),
+          str: myzod.string()
+        })
+      }
+      "
+    `)
+  });
   it('with typesPrefix', async () => {
     const schema = buildSchema(/* GraphQL */ `
       input Say {

tests/valibot.spec.ts

@@ -433,6 +433,43 @@ describe('valibot', () => {
       "
     `)
   });
+
+  it('with defaultScalarTypeSchema', async () => {
+    const schema = buildSchema(/* GraphQL */ `
+      input ScalarsInput {
+        date: Date!
+        email: Email
+        str: String!
+      }
+      scalar Date
+      scalar Email
+    `);
+    const result = await plugin(
+      schema,
+      [],
+      {
+        schema: 'valibot',
+        scalarSchemas: {
+          Email: 'v.string([v.email()])',
+        },
+        defaultScalarTypeSchema: 'v.string()',
+      },
+      {},
+    );
+    expect(result.content).toMatchInlineSnapshot(`
+      "
+
+      export function ScalarsInputSchema(): v.GenericSchema<ScalarsInput> {
+        return v.object({
+          date: v.string(),
+          email: v.nullish(v.string([v.email()])),
+          str: v.string()
+        })
+      }
+      "
+    `)
+  });
+
   it('with typesPrefix', async () => {
     const schema = buildSchema(/* GraphQL */ `
       input Say {

tests/yup.spec.ts

@@ -472,6 +472,41 @@ describe('yup', () => {
     `)
   });
 
+  it('with defaultScalarTypeSchema', async () => {
+    const schema = buildSchema(/* GraphQL */ `
+      input ScalarsInput {
+        date: Date!
+        email: Email
+        str: String!
+      }
+      scalar Date
+      scalar Email
+    `);
+    const result = await plugin(
+      schema,
+      [],
+      {
+        scalarSchemas: {
+          Email: 'yup.string().email()',
+        },
+        defaultScalarTypeSchema: 'yup.string()',
+      },
+      {},
+    );
+    expect(result.content).toMatchInlineSnapshot(`
+      "
+
+      export function ScalarsInputSchema(): yup.ObjectSchema<ScalarsInput> {
+        return yup.object({
+          date: yup.string().nonNullable(),
+          email: yup.string().email().defined().nullable().optional(),
+          str: yup.string().defined().nonNullable()
+        })
+      }
+      "
+    `)
+  });
+
   it('with typesPrefix', async () => {
     const schema = buildSchema(/* GraphQL */ `
       input Say {

tests/zod.spec.ts

@@ -464,6 +464,41 @@ describe('zod', () => {
     `)
   });
 
+  it('with defaultScalarTypeSchema', async () => {
+    const schema = buildSchema(/* GraphQL */ `
+      input ScalarsInput {
+        date: Date!
+        email: Email
+        str: String!
+      }
+      scalar Date
+      scalar Email
+    `);
+    const result = await plugin(
+      schema,
+      [],
+      {
+        schema: 'zod',
+        scalarSchemas: {
+          Email: 'z.string().email()',
+        },
+        defaultScalarTypeSchema: 'z.string()',
+      },
+      {},
+    );
+    expect(removedInitialEmitValue(result.content)).toMatchInlineSnapshot(`
+      "
+      export function ScalarsInputSchema(): z.ZodObject<Properties<ScalarsInput>> {
+        return z.object({
+          date: z.string(),
+          email: z.string().email().nullish(),
+          str: z.string()
+        })
+      }
+      "
+    `)
+  });
+
   it('with typesPrefix', async () => {
     const schema = buildSchema(/* GraphQL */ `
       input Say {