refactor: strengthen test infrastructure and consolidate shared logic

package.json

@@ -58,11 +58,11 @@
   ],
   "scripts": {
     "type-check": "tsc --noEmit",
-    "type-check:yup": "tsc --strict --skipLibCheck --noEmit example/yup/schemas.ts",
-    "type-check:zod": "tsc --strict --skipLibCheck --noEmit example/zod/schemas.ts",
-    "type-check:zodv4": "tsc --strict --skipLibCheck --noEmit example/zodv4/schemas.ts",
-    "type-check:myzod": "tsc --strict --skipLibCheck --noEmit example/myzod/schemas.ts",
-    "type-check:valibot": "tsc --strict --skipLibCheck --noEmit example/valibot/schemas.ts",
+    "type-check:yup": "tsc --strict --skipLibCheck --noEmit --ignoreConfig example/yup/schemas.ts",
+    "type-check:zod": "tsc --strict --skipLibCheck --noEmit --ignoreConfig example/zod/schemas.ts",
+    "type-check:zodv4": "tsc --strict --skipLibCheck --noEmit --ignoreConfig example/zodv4/schemas.ts",
+    "type-check:myzod": "tsc --strict --skipLibCheck --noEmit --ignoreConfig example/myzod/schemas.ts",
+    "type-check:valibot": "tsc --strict --skipLibCheck --noEmit --ignoreConfig example/valibot/schemas.ts",
     "test": "vitest run",
     "build": "run-p build:*",
     "build:cjs": "tsc -p tsconfig.cjs.json && echo '{\"type\":\"commonjs\"}' > dist/cjs/package.json",

src/lazy.ts

@@ -0,0 +1,29 @@
+import type { TypeNode } from 'graphql';
+import type { Visitor } from './visitor.js';
+
+import { isEnumType, isScalarType } from 'graphql';
+import { isNamedType } from './graphql.js';
+
+/**
+ * Wraps a schema expression in a library-specific lazy reference when the type
+ * is a complex (non-scalar, non-enum) named type — avoiding issues with
+ * mutually-recursive input types.
+ *
+ * Each validation library has its own lazy syntax (z.lazy, v.lazy, etc.), so
+ * callers supply the wrapper function.
+ *
+ * @param lazyWrapper - e.g. `(s) => \`z.lazy(() => ${s})\``
+ */
+export function buildMaybeLazy(
+  visitor: Visitor,
+  type: TypeNode,
+  schema: string,
+  lazyWrapper: (schema: string) => string,
+): string {
+  if (!isNamedType(type))
+    return schema;
+
+  const schemaType = visitor.getType(type.name.value);
+  const isComplexType = !isScalarType(schemaType) && !isEnumType(schemaType);
+  return isComplexType ? lazyWrapper(schema) : schema;
+}

src/myzod/index.ts

@@ -16,8 +16,6 @@ import type { Visitor } from '../visitor.js';
 import { resolveExternalModuleAndFn } from '@graphql-codegen/plugin-helpers';
 import { convertNameParts, DeclarationBlock, indent } from '@graphql-codegen/visitor-plugin-common';
 import {
-  isEnumType,
-  isScalarType,
   Kind,
 } from 'graphql';
 import { buildApi, formatDirectiveConfig } from '../directive.js';
@@ -29,6 +27,8 @@ import {
   isNonNullType,
   ObjectTypeDefinitionBuilder,
 } from '../graphql.js';
+import { buildMaybeLazy } from '../lazy.js';
+import { buildScalarSchema } from '../scalar.js';
 import { BaseSchemaVisitor } from '../schema_visitor.js';
 
 const anySchema = `definedNonNullAnySchema`;
@@ -365,33 +365,12 @@ function generateNameNodeMyZodSchema(config: ValidationSchemaPluginConfig, visit
 }
 
 function maybeLazy(visitor: Visitor, type: TypeNode, schema: string): string {
-  if (!isNamedType(type)) {
-    return schema;
-  }
-
-  const schemaType = visitor.getType(type.name.value);
-  const isComplexType = !isScalarType(schemaType) && !isEnumType(schemaType);
-  return isComplexType ? `myzod.lazy(() => ${schema})` : schema;
+  return buildMaybeLazy(visitor, type, schema, s => `myzod.lazy(() => ${s})`);
 }
 
 function myzod4Scalar(config: ValidationSchemaPluginConfig, visitor: Visitor, scalarName: string): string {
-  if (config.scalarSchemas?.[scalarName])
-    return config.scalarSchemas[scalarName];
-
-  const tsType = visitor.getScalarType(scalarName);
-  switch (tsType) {
-    case 'string':
-      return `myzod.string()`;
-    case 'number':
-      return `myzod.number()`;
-    case 'boolean':
-      return `myzod.boolean()`;
-  }
-
-  if (config.defaultScalarTypeSchema) {
-    return config.defaultScalarTypeSchema;
-  }
-
-  console.warn('unhandled name:', scalarName);
-  return anySchema;
+  return buildScalarSchema(config, visitor, scalarName, {
+    typeMap: { string: 'myzod.string()', number: 'myzod.number()', boolean: 'myzod.boolean()' },
+    fallback: anySchema,
+  });
 }

src/scalar.ts

@@ -0,0 +1,39 @@
+import type { ValidationSchemaPluginConfig } from './config.js';
+import type { Visitor } from './visitor.js';
+
+/**
+ * Builds a library-specific scalar schema expression.
+ *
+ * All five validation libraries follow the same pattern: check for a custom
+ * `scalarSchemas` override, fall back to a built-in type map for the resolved
+ * TypeScript type (string/number/boolean), then apply `defaultScalarTypeSchema`,
+ * and finally warn and return the library fallback.
+ *
+ * The only per-library differences are the strings in `typeMap`, the `fallback`
+ * value, and whether custom schemas need wrapping (yup appends `.defined()`).
+ */
+export function buildScalarSchema(
+  config: ValidationSchemaPluginConfig,
+  visitor: Visitor,
+  scalarName: string,
+  options: {
+    typeMap: Record<'string' | 'number' | 'boolean', string>
+    fallback: string
+    wrapCustom?: (schema: string) => string
+  },
+): string {
+  if (config.scalarSchemas?.[scalarName]) {
+    const custom = config.scalarSchemas[scalarName];
+    return options.wrapCustom ? options.wrapCustom(custom) : custom;
+  }
+
+  const tsType = visitor.getScalarType(scalarName);
+  if (tsType != null && tsType in options.typeMap)
+    return options.typeMap[tsType as keyof typeof options.typeMap];
+
+  if (config.defaultScalarTypeSchema)
+    return config.defaultScalarTypeSchema;
+
+  console.warn('unhandled scalar name:', scalarName);
+  return options.fallback;
+}

src/valibot/index.ts

@@ -14,7 +14,6 @@ import type { ValidationSchemaPluginConfig } from '../config.js';
 import type { Visitor } from '../visitor.js';
 import { DeclarationBlock, indent } from '@graphql-codegen/visitor-plugin-common';
 
-import { isEnumType, isScalarType } from 'graphql';
 import { buildApiForValibot, formatDirectiveConfig } from '../directive.js';
 import {
   InterfaceTypeDefinitionBuilder,
@@ -23,6 +22,8 @@ import {
   isNonNullType,
   ObjectTypeDefinitionBuilder,
 } from '../graphql.js';
+import { buildMaybeLazy } from '../lazy.js';
+import { buildScalarSchema } from '../scalar.js';
 import { BaseSchemaVisitor } from '../schema_visitor.js';
 
 export class ValibotSchemaVisitor extends BaseSchemaVisitor {
@@ -287,33 +288,12 @@ function generateNameNodeValibotSchema(config: ValidationSchemaPluginConfig, vis
 }
 
 function maybeLazy(visitor: Visitor, type: TypeNode, schema: string): string {
-  if (!isNamedType(type)) {
-    return schema;
-  }
-
-  const schemaType = visitor.getType(type.name.value);
-  const isComplexType = !isScalarType(schemaType) && !isEnumType(schemaType);
-  return isComplexType ? `v.lazy(() => ${schema})` : schema;
+  return buildMaybeLazy(visitor, type, schema, s => `v.lazy(() => ${s})`);
 }
 
 function valibot4Scalar(config: ValidationSchemaPluginConfig, visitor: Visitor, scalarName: string): string {
-  if (config.scalarSchemas?.[scalarName])
-    return config.scalarSchemas[scalarName];
-
-  const tsType = visitor.getScalarType(scalarName);
-  switch (tsType) {
-    case 'string':
-      return `v.string()`;
-    case 'number':
-      return `v.number()`;
-    case 'boolean':
-      return `v.boolean()`;
-  }
-
-  if (config.defaultScalarTypeSchema) {
-    return config.defaultScalarTypeSchema;
-  }
-
-  console.warn('unhandled scalar name:', scalarName);
-  return 'v.any()';
+  return buildScalarSchema(config, visitor, scalarName, {
+    typeMap: { string: 'v.string()', number: 'v.number()', boolean: 'v.boolean()' },
+    fallback: 'v.any()',
+  });
 }

src/yup/index.ts

@@ -16,8 +16,6 @@ import type { Visitor } from '../visitor.js';
 import { resolveExternalModuleAndFn } from '@graphql-codegen/plugin-helpers';
 import { convertNameParts, DeclarationBlock, indent } from '@graphql-codegen/visitor-plugin-common';
 import {
-  isEnumType,
-  isScalarType,
   Kind,
 } from 'graphql';
 import { buildApi, formatDirectiveConfig } from '../directive.js';
@@ -29,6 +27,8 @@ import {
   isNonNullType,
   ObjectTypeDefinitionBuilder,
 } from '../graphql.js';
+import { buildMaybeLazy } from '../lazy.js';
+import { buildScalarSchema } from '../scalar.js';
 import { BaseSchemaVisitor } from '../schema_visitor.js';
 
 export class YupSchemaVisitor extends BaseSchemaVisitor {
@@ -391,33 +391,13 @@ function generateNameNodeYupSchema(config: ValidationSchemaPluginConfig, visitor
 }
 
 function maybeLazy(visitor: Visitor, type: TypeNode, schema: string): string {
-  if (!isNamedType(type)) {
-    return schema;
-  }
-
-  const schemaType = visitor.getType(type.name.value);
-  const isComplexType = !isScalarType(schemaType) && !isEnumType(schemaType);
-  return isComplexType ? `yup.lazy(() => ${schema})` : schema;
+  return buildMaybeLazy(visitor, type, schema, s => `yup.lazy(() => ${s})`);
 }
 
 function yup4Scalar(config: ValidationSchemaPluginConfig, visitor: Visitor, scalarName: string): string {
-  if (config.scalarSchemas?.[scalarName])
-    return `${config.scalarSchemas[scalarName]}.defined()`;
-
-  const tsType = visitor.getScalarType(scalarName);
-  switch (tsType) {
-    case 'string':
-      return `yup.string().defined()`;
-    case 'number':
-      return `yup.number().defined()`;
-    case 'boolean':
-      return `yup.boolean().defined()`;
-  }
-
-  if (config.defaultScalarTypeSchema) {
-    return config.defaultScalarTypeSchema
-  }
-
-  console.warn('unhandled name:', scalarName);
-  return `yup.mixed()`;
+  return buildScalarSchema(config, visitor, scalarName, {
+    typeMap: { string: 'yup.string().defined()', number: 'yup.number().defined()', boolean: 'yup.boolean().defined()' },
+    fallback: 'yup.mixed()',
+    wrapCustom: s => `${s}.defined()`,
+  });
 }