From 962bd87217212320b1a68f6556a16b8a6b8f757c Mon Sep 17 00:00:00 2001
From: David Luecke <daff@neyeon.com>
Date: Wed, 12 Apr 2023 10:20:15 -0700
Subject: [PATCH] fix(typebox): Implement custom TypeBuilder for backwards
 compatibility (#3150)

---
 packages/typebox/src/index.ts       | 66 ++++++++++++++++++++++++++---
 packages/typebox/test/index.test.ts |  5 +++
 2 files changed, 64 insertions(+), 7 deletions(-)

diff --git a/packages/typebox/src/index.ts b/packages/typebox/src/index.ts
index c8d5617836..f291cc295e 100644
--- a/packages/typebox/src/index.ts
+++ b/packages/typebox/src/index.ts
@@ -1,14 +1,66 @@
-import { Type, TObject, TInteger, TOptional, TSchema, TIntersect, ObjectOptions } from '@sinclair/typebox'
+import {
+  TObject,
+  TInteger,
+  TOptional,
+  TSchema,
+  TIntersect,
+  ObjectOptions,
+  ExtendedTypeBuilder,
+  SchemaOptions,
+  TNever,
+  IntersectOptions,
+  TypeGuard,
+  Kind
+} from '@sinclair/typebox'
 import { jsonSchema, Validator, DataValidatorMap, Ajv } from '@feathersjs/schema'
 
 export * from '@sinclair/typebox'
 export * from './default-schemas'
 
-// Export new intersect
-export const Intersect = Type.Intersect
+/**
+ * Feathers TypeBox customisations. Implements the 0.25.0 fallback for Intersect types.
+ * @see https://github.com/sinclairzx81/typebox/issues/373
+ */
+export class FeathersTypeBuilder extends ExtendedTypeBuilder {
+  /** `[Standard]` Creates a Intersect type */
+  public Intersect(allOf: [], options?: SchemaOptions): TNever
+  /** `[Standard]` Creates a Intersect type */
+  public Intersect<T extends [TObject]>(allOf: [...T], options?: SchemaOptions): T[0]
+  // /** `[Standard]` Creates a Intersect type */
+  public Intersect<T extends TObject[]>(allOf: [...T], options?: IntersectOptions): TIntersect<T>
+  public Intersect(allOf: TObject[], options: IntersectOptions = {}) {
+    const [required, optional] = [new Set<string>(), new Set<string>()]
+    for (const object of allOf) {
+      for (const [key, property] of Object.entries(object.properties)) {
+        if (TypeGuard.TOptional(property) || TypeGuard.TReadonlyOptional(property)) optional.add(key)
+      }
+    }
+    for (const object of allOf) {
+      for (const key of Object.keys(object.properties)) {
+        if (!optional.has(key)) required.add(key)
+      }
+    }
+    const properties = {} as Record<string, any>
+    for (const object of allOf) {
+      for (const [key, schema] of Object.entries(object.properties)) {
+        properties[key] =
+          properties[key] === undefined
+            ? schema
+            : { [Kind]: 'Union', anyOf: [properties[key], { ...schema }] }
+      }
+    }
+    if (required.size > 0) {
+      return { ...options, [Kind]: 'Object', type: 'object', properties, required: [...required] } as any
+    } else {
+      return { ...options, [Kind]: 'Object', type: 'object', properties } as any
+    }
+  }
+}
 
-// This is necessary to maintain backwards compatibility between 0.25 and 0.26
-Type.Intersect = Type.Composite as any
+/**
+ * Exports our own type builder
+ */
+export const Type = new FeathersTypeBuilder()
 
 export type TDataSchemaMap = {
   create: TObject
@@ -94,7 +146,7 @@ export const queryProperty = <T extends TSchema, X extends { [key: string]: TSch
     Type.Union([
       def,
       Type.Partial(
-        Type.Intersect(
+        Type.Composite(
           [
             Type.Object({
               $gt: def,
@@ -164,7 +216,7 @@ export const querySyntax = <
   const $or = Type.Array(propertySchema)
   const $and = Type.Array(Type.Union([propertySchema, Type.Object({ $or })]))
 
-  return Type.Intersect(
+  return Type.Composite(
     [
       Type.Partial(
         Type.Object(
diff --git a/packages/typebox/test/index.test.ts b/packages/typebox/test/index.test.ts
index 5b1b383123..40aa4367da 100644
--- a/packages/typebox/test/index.test.ts
+++ b/packages/typebox/test/index.test.ts
@@ -10,6 +10,7 @@ import {
   getValidator,
   ObjectIdSchema
 } from '../src'
+import { FeathersTypeBuilder } from '../src'
 
 describe('@feathersjs/schema/typebox', () => {
   describe('querySyntax', () => {
@@ -100,6 +101,10 @@ describe('@feathersjs/schema/typebox', () => {
     assert.ok(validated)
   })
 
+  it('exports custom type builder', () => {
+    assert.ok(Type instanceof FeathersTypeBuilder)
+  })
+
   // Test ObjectId validation
   it('ObjectId', async () => {
     const schema = Type.Object({