fix: circular ref when optional

LuciNyan · Mar 2, 2023 · fea3d2d · fea3d2d
1 parent c4a1e85
commit fea3d2d
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Showing 4 changed files with 24 additions and 15 deletions.
diff --git a/src/operator.test.ts b/src/operator.test.ts
@@ -20,14 +20,14 @@ describe('objectOf', () => {
   it('should return a function that checks if an object with circular reference is of correct type', () => {
     const guard = objectOf({
       name: isString,
-      ref: SELF,
+      ref: optional(SELF),
       age: optional(isNumber),
     })
 
     const elem: any = { name: 'element' }
 
     elem.abc = elem
-    expect(guard(elem)).toBe(false)
+    expect(guard(elem)).toBe(true)
 
     elem.ref = false
     expect(guard(elem)).toBe(false)

diff --git a/src/operator.ts b/src/operator.ts
@@ -36,14 +36,17 @@ export function intersection<T extends any[]>(
 }
 
 export function optional<T>(guard: Guard<T>): Guard<T> & {
-  isOptional: true
+  __isOptional: true
 } {
   const _guard = (...args: Parameters<Guard<T>>) => guard(...args)
 
-  _guard.isOptional = true
+  _guard.__isOptional = true
+  if (guard.__isSelf) {
+    _guard.__isSelf = guard.__isSelf
+  }
 
   return _guard as Guard<T> & {
-    isOptional: true
+    __isOptional: true
   }
 }
 

diff --git a/src/property.ts b/src/property.ts
@@ -1,21 +1,23 @@
 import { isObject } from './base'
 import { Guard, GuardConfig, MakeTypeFromConfig } from './utils'
 
-export const SELF: Guard<any> = (x: unknown): x is any => true
-SELF.isSelf = true
+const circularRefPlaceholder: Guard<any> = (x: unknown): x is any => true
+circularRefPlaceholder.__isSelf = true
+
+export const SELF = circularRefPlaceholder
 
 export function hasUnknownProperty<K extends string>(x: unknown, name: K): x is { [Key in K]: unknown } {
   return isObject(x) && name in x
 }
 
 export function hasProperty<K extends string, V>(x: unknown, name: K, guard: Guard<V>): x is { [Key in K]: V } {
   if (!hasUnknownProperty(x, name)) {
-    return !!guard.isOptional
+    return !!guard.__isOptional
   }
 
   const memo = new Set([x])
 
-  if (guard === SELF) {
+  if (isCircularRefPlaceholder(guard)) {
     return _hasProperty(x[name], name, SELF, memo)
   }
 
@@ -38,12 +40,12 @@ export function _hasProperty<K extends string, V, R extends GuardConfig>(
   guardByProperty?: R
 ): x is { [Key in K]: V } {
   if (!hasUnknownProperty(x, name)) {
-    return !!guard.isOptional
+    return !!guard.__isOptional
   }
 
   memo.add(x)
 
-  if (guard === SELF && guardByProperty) {
+  if (isCircularRefPlaceholder(guard) && guardByProperty) {
     return memo.has(x[name]) ? true : _hasProperties(x[name], guardByProperty, memo)
   }
 
@@ -61,3 +63,7 @@ export function _hasProperties<R extends GuardConfig>(
     return _hasProperty(x, key, guard, memo, guardByProperty)
   })
 }
+
+function isCircularRefPlaceholder(x: Guard<unknown>): boolean {
+  return !!x.__isSelf
+}
diff --git a/src/utils.ts b/src/utils.ts
@@ -1,8 +1,8 @@
 export type UnionToIntersection<U> = (U extends any ? (k: U) => void : never) extends (k: infer I) => void ? I : never
 
 export type Guard<T> = ((x: unknown) => x is T) & {
-  isOptional?: boolean
-  isSelf?: boolean
+  __isOptional?: boolean
+  __isSelf?: boolean
 }
 
 export type GuardFor<T> = T extends Guard<infer R> ? R : never
@@ -17,7 +17,7 @@ export type MakeTypeFromConfig<T extends Record<PropertyKey, Guard<unknown>>> =
 >
 
 type handleMetadataIsOptional<T extends GuardConfig, K extends keyof T> = K extends K
-  ? T[K] extends { isOptional: true }
+  ? T[K] extends { __isOptional: true }
     ? {
         [Key in keyof T as Key extends K ? Key : never]?: T[K]
       }
@@ -27,7 +27,7 @@ type handleMetadataIsOptional<T extends GuardConfig, K extends keyof T> = K exte
   : never
 
 type handleMetadataIsSelf<T> = {
-  [K in keyof T]: T[K] extends { isSelf: true } ? handleMetadataIsSelf<T> : GuardFor<T[K]>
+  [K in keyof T]: T[K] extends { __isSelf: true } ? handleMetadataIsSelf<T> : GuardFor<T[K]>
 }
 
 export function toString(x: unknown): string {