feat: Add support for Date type in TypeBox codegen (#16)

This change adds a new `DateTypeHandler` class that can handle the `Date` type in TypeScript. The `DateTypeHandler` is registered in the `TypeBoxTypeHandlers` class, allowing the codegen to generate TypeBox expressions for `Date` types.

This enhancement provides native support for the JavaScript `Date` type, making it easier to work with date-related data in the generated validation schemas.

Author: DaxServer

ARCHITECTURE.md

@@ -28,6 +28,7 @@
 - **Complex Types**: Union and intersection types, nested object structures, template literal types
 - **Utility Types**: Built-in support for Pick, Omit, Partial, Required, Record, Readonly, and other TypeScript utility types
 - **Advanced Features**: Conditional types, mapped types, keyof operators, indexed access types
+- **JavaScript Built-in Types**: Native support for Date type using TypeBox's JavaScript type system
 - **Import Resolution**: Cross-file type dependencies with qualified naming and circular dependency handling
 
 ## Core Components
@@ -133,8 +134,9 @@ The handler system in <mcfile name="handlers/typebox" path="src/handlers/typebox
 6. **Simple Handlers**: <mcfile name="simple-type-handler.ts" path="src/handlers/typebox/simple-type-handler.ts"></mcfile>, <mcfile name="literal-type-handler.ts" path="src/handlers/typebox/literal-type-handler.ts"></mcfile>
 7. **Advanced Handlers**: <mcfile name="template-literal-type-handler.ts" path="src/handlers/typebox/template-literal-type-handler.ts"></mcfile>, <mcfile name="type-operator-handler.ts" path="src/handlers/typebox/type-operator-handler.ts"></mcfile>, <mcfile name="keyof-type-handler.ts" path="src/handlers/typebox/keyof-type-handler.ts"></mcfile>
 8. **Function Handlers**: <mcfile name="function-type-handler.ts" path="src/handlers/typebox/function-type-handler.ts"></mcfile>
-9. **Type Query Handlers**: <mcfile name="type-query-handler.ts" path="src/handlers/typebox/type-query-handler.ts"></mcfile>, <mcfile name="typeof-type-handler.ts" path="src/handlers/typebox/typeof-type-handler.ts"></mcfile>
-10. **Access Handlers**: <mcfile name="indexed-access-type-handler.ts" path="src/handlers/typebox/indexed-access-type-handler.ts"></mcfile>, <mcfile name="type-reference-handler.ts" path="src/handlers/typebox/type-reference-handler.ts"></mcfile>
+9. **JavaScript Type Handlers**: <mcfile name="date-type-handler.ts" path="src/handlers/typebox/date-type-handler.ts"></mcfile> - Handles JavaScript built-in types like Date using TypeBox's extended type system
+10. **Type Query Handlers**: <mcfile name="type-query-handler.ts" path="src/handlers/typebox/type-query-handler.ts"></mcfile>, <mcfile name="typeof-type-handler.ts" path="src/handlers/typebox/typeof-type-handler.ts"></mcfile>
+11. **Access Handlers**: <mcfile name="indexed-access-type-handler.ts" path="src/handlers/typebox/indexed-access-type-handler.ts"></mcfile>, <mcfile name="type-reference-handler.ts" path="src/handlers/typebox/type-reference-handler.ts"></mcfile>
 
 #### Readonly Type Handling
 
@@ -157,11 +159,20 @@ This dual approach ensures proper handling of both TypeScript readonly construct
 - `type ReadonlyArray = readonly string[]` (array modifier)
 - `type ReadonlyTuple = readonly [string, number]` (tuple modifier)
 
+#### JavaScript Built-in Type Support
+
+The system provides comprehensive support for JavaScript built-in types through specialized handlers:
+
+- **Date Type Handler**: The <mcfile name="date-type-handler.ts" path="src/handlers/typebox/date-type-handler.ts"></mcfile> handles TypeScript's `Date` type references and converts them to TypeBox's `Type.Date()` schema
+- **Type Reference Registration**: JavaScript built-in types are registered in the `typeReferenceHandlers` map for O(1) lookup performance
+- **Extended Type System**: Leverages TypeBox's JavaScript type system for types that extend beyond standard JSON Schema
+
 #### Handler Management
 
 The <mcfile name="typebox-type-handlers.ts" path="src/handlers/typebox/typebox-type-handlers.ts"></mcfile> class orchestrates all handlers through:
 
 - **Handler Caching**: Caches handler instances for performance optimization
+- **Type Reference Mapping**: O(1) lookup for built-in types like Date, utility types like Partial, and other type references
 - **Fallback System**: Provides fallback handlers for complex cases including readonly array modifiers
 
 ### Import Resolution

src/handlers/typebox/date-type-handler.ts

@@ -0,0 +1,16 @@
+import { BaseTypeHandler } from '@daxserver/validation-schema-codegen/handlers/typebox/base-type-handler'
+import { makeTypeCall } from '@daxserver/validation-schema-codegen/utils/typebox-codegen-utils'
+import { Node, ts, TypeReferenceNode } from 'ts-morph'
+
+export class DateTypeHandler extends BaseTypeHandler {
+  canHandle(node: TypeReferenceNode): boolean {
+    const typeName = node.getTypeName()
+
+    return Node.isIdentifier(typeName) && typeName.getText() === 'Date'
+  }
+
+  // eslint-disable-next-line @typescript-eslint/no-unused-vars
+  handle(_node: TypeReferenceNode): ts.Expression {
+    return makeTypeCall('Date')
+  }
+}

src/handlers/typebox/typebox-type-handlers.ts

@@ -3,6 +3,7 @@ import { ArrayTypeHandler } from '@daxserver/validation-schema-codegen/handlers/
 import { IntersectionTypeHandler } from '@daxserver/validation-schema-codegen/handlers/typebox/collection/intersection-type-handler'
 import { TupleTypeHandler } from '@daxserver/validation-schema-codegen/handlers/typebox/collection/tuple-type-handler'
 import { UnionTypeHandler } from '@daxserver/validation-schema-codegen/handlers/typebox/collection/union-type-handler'
+import { DateTypeHandler } from '@daxserver/validation-schema-codegen/handlers/typebox/date-type-handler'
 import { FunctionTypeHandler } from '@daxserver/validation-schema-codegen/handlers/typebox/function-type-handler'
 import { IndexedAccessTypeHandler } from '@daxserver/validation-schema-codegen/handlers/typebox/indexed-access-type-handler'
 import { KeyOfTypeHandler } from '@daxserver/validation-schema-codegen/handlers/typebox/keyof-type-handler'
@@ -52,6 +53,7 @@ export class TypeBoxTypeHandlers {
     const typeofTypeHandler = new TypeofTypeHandler()
     const readonlyTypeHandler = new ReadonlyTypeHandler()
     const readonlyArrayTypeHandler = new ReadonlyArrayTypeHandler()
+    const dateTypeHandler = new DateTypeHandler()
 
     // O(1) lookup by SyntaxKind
     this.syntaxKindHandlers.set(SyntaxKind.AnyKeyword, simpleTypeHandler)
@@ -83,6 +85,7 @@ export class TypeBoxTypeHandlers {
     this.typeReferenceHandlers.set('Omit', omitTypeHandler)
     this.typeReferenceHandlers.set('Required', requiredTypeHandler)
     this.typeReferenceHandlers.set('Readonly', readonlyTypeHandler)
+    this.typeReferenceHandlers.set('Date', dateTypeHandler)
 
     // Fallback handlers for complex cases
     this.fallbackHandlers = [

tests/handlers/typebox/date-types.test.ts

@@ -0,0 +1,113 @@
+import { createSourceFile, formatWithPrettier, generateFormattedCode } from '@test-fixtures/utils'
+import { beforeEach, describe, expect, test } from 'bun:test'
+import { Project } from 'ts-morph'
+
+describe('Date types', () => {
+  let project: Project
+
+  beforeEach(() => {
+    project = new Project()
+  })
+
+  test('without export', () => {
+    const sourceFile = createSourceFile(project, `type A = Date`)
+
+    expect(generateFormattedCode(sourceFile)).toBe(
+      formatWithPrettier(`
+        export const A = Type.Date();
+
+        export type A = Static<typeof A>;
+      `),
+    )
+  })
+
+  test('with export', () => {
+    const sourceFile = createSourceFile(project, `export type A = Date`)
+
+    expect(generateFormattedCode(sourceFile)).toBe(
+      formatWithPrettier(`
+        export const A = Type.Date();
+
+        export type A = Static<typeof A>;
+      `),
+    )
+  })
+
+  test('simple Date type alias', () => {
+    const sourceFile = createSourceFile(project, `type Timestamp = Date`)
+
+    expect(generateFormattedCode(sourceFile)).toBe(
+      formatWithPrettier(`
+        export const Timestamp = Type.Date();
+
+        export type Timestamp = Static<typeof Timestamp>;
+      `),
+    )
+  })
+
+  test('Date in object property', () => {
+    const sourceFile = createSourceFile(
+      project,
+      `
+      interface User {
+        name: string;
+        createdAt: Date;
+      }
+    `,
+    )
+
+    expect(generateFormattedCode(sourceFile)).toBe(
+      formatWithPrettier(`
+        export const User = Type.Object({
+          name: Type.String(),
+          createdAt: Type.Date(),
+        });
+
+        export type User = Static<typeof User>;
+      `),
+    )
+  })
+
+  test('Date in union type', () => {
+    const sourceFile = createSourceFile(project, `type Value = string | Date | number`)
+
+    expect(generateFormattedCode(sourceFile)).toBe(
+      formatWithPrettier(`
+        export const Value = Type.Union([Type.String(), Type.Date(), Type.Number()]);
+
+        export type Value = Static<typeof Value>;
+      `),
+    )
+  })
+
+  test('Date in array', () => {
+    const sourceFile = createSourceFile(project, `type Dates = Date[]`)
+
+    expect(generateFormattedCode(sourceFile)).toBe(
+      formatWithPrettier(`
+        export const Dates = Type.Array(Type.Date());
+
+        export type Dates = Static<typeof Dates>;
+      `),
+    )
+  })
+
+  test('Date in function parameter and return type', () => {
+    const sourceFile = createSourceFile(
+      project,
+      `
+      function formatDate(date: Date): string {
+        return date.toString();
+      }
+    `,
+    )
+
+    expect(generateFormattedCode(sourceFile)).toBe(
+      formatWithPrettier(`
+        export const formatDate = Type.Function([Type.Date()], Type.String());
+
+        export type formatDate = Static<typeof formatDate>;
+      `),
+    )
+  })
+})