Convert date to string

docs/object-utils.md

@@ -24,10 +24,14 @@ Returns an object which contains fields specified in `propNames` with the same v
 
 Returns true if `params` has no own properties or only own properties with value `undefined`, false otherwise.
 
-`export function groupBy<T extends { [K in keyof T]: string | number | symbol | null | undefined }, K extends keyof T>(array: T[], selector: K): Record<string | number | symbol, T[]>`
+`groupBy<T extends { [K in keyof T]: string | number | symbol | null | undefined }, K extends keyof T>(array: T[], selector: K): Record<string | number | symbol, T[]>`
 
 The `groupBy` function takes an array of objects and a `selector`, groups the objects based on selected key and returns an object with unique keys from the selector and corresponding groups as arrays.
 
-`export function groupByUnique<T extends { [K in keyof T]: string | number | symbol | null | undefined }, K extends keyof T>(array: T[], selector: K): Record<string | number | symbol, T>`
+`groupByUnique<T extends { [K in keyof T]: string | number | symbol | null | undefined }, K extends keyof T>(array: T[], selector: K): Record<string | number | symbol, T>`
 
 Similar to `groupBy`, but the value is a single element, in case of duplicated values for the same selector the method will throw a `InternalError`
+
+`convertDateFieldsToIsoString<Input extends object>(object: Input | Input[],): ExactlyLikeWithDateAsString<Input> | ExactlyLikeWithDateAsString<Input>[]`
+
+Transform an input object with `Date` members into an object with the corresponding `Date` members replaced by their ISO string representation. This transformation is done recursively, covering nested objects as well.

index.ts

@@ -43,6 +43,7 @@ export {
   pickWithoutUndefined,
   copyWithoutUndefined,
   isEmptyObject,
+  convertDateFieldsToIsoString,
 } from './src/utils/objectUtils'
 
 export {

src/utils/objectUtils.spec.ts

@@ -1,6 +1,7 @@
 import { expect } from 'vitest'
 
 import {
+  convertDateFieldsToIsoString,
   copyWithoutUndefined,
   groupBy,
   groupByUnique,
@@ -371,4 +372,178 @@ describe('objectUtils', () => {
       )
     })
   })
+
+  describe('convertDateFieldsToIsoString', () => {
+    it('Empty object', () => {
+      expect(convertDateFieldsToIsoString({})).toStrictEqual({})
+    })
+
+    type TestInputType = {
+      id: number
+      value: string
+      date: Date
+      code: number
+      reason?: string | null
+      other?: TestInputType
+      array?: {
+        id: number
+        createdAt: Date
+      }[]
+    }
+
+    type TestExpectedType = {
+      id: number
+      value: string
+      date: string
+      code: number
+      other?: TestExpectedType
+      array?: {
+        id: number
+        createdAt: string
+      }[]
+    }
+
+    it('simple object', () => {
+      const date = new Date()
+      const input: TestInputType = {
+        id: 1,
+        date,
+        value: 'test',
+        reason: 'reason',
+        code: 100,
+      }
+
+      const output: TestExpectedType = convertDateFieldsToIsoString(input)
+
+      expect(output).toStrictEqual({
+        id: 1,
+        date: date.toISOString(),
+        value: 'test',
+        code: 100,
+        reason: 'reason',
+      })
+    })
+
+    it('simple array', () => {
+      const date1 = new Date()
+      const date2 = new Date()
+      const input: TestInputType[] = [
+        {
+          id: 1,
+          date: date1,
+          value: 'test',
+          reason: 'reason',
+          code: 100,
+        },
+        {
+          id: 2,
+          date: date2,
+          value: 'test 2',
+          reason: 'reason 2',
+          code: 200,
+        },
+      ]
+
+      const output: TestExpectedType[] = convertDateFieldsToIsoString(input)
+
+      expect(output).toStrictEqual([
+        {
+          id: 1,
+          date: date1.toISOString(),
+          value: 'test',
+          code: 100,
+          reason: 'reason',
+        },
+        {
+          id: 2,
+          date: date2.toISOString(),
+          value: 'test 2',
+          code: 200,
+          reason: 'reason 2',
+        },
+      ])
+    })
+
+    it('handles undefined and null', () => {
+      const date = new Date()
+      const input: TestInputType = {
+        id: 1,
+        date,
+        value: 'test',
+        code: 100,
+        reason: null,
+        other: undefined,
+      }
+
+      const output: TestExpectedType = convertDateFieldsToIsoString(input)
+
+      expect(output).toStrictEqual({
+        id: 1,
+        date: date.toISOString(),
+        value: 'test',
+        code: 100,
+        reason: null,
+        other: undefined,
+      })
+    })
+
+    it('nested objects and array', () => {
+      const date1 = new Date()
+      const date2 = new Date()
+      date2.setFullYear(1990)
+      const input: TestInputType = {
+        id: 1,
+        date: date1,
+        value: 'test',
+        code: 100,
+        reason: 'reason',
+        other: {
+          id: 2,
+          value: 'test 2',
+          date: date2,
+          code: 200,
+          reason: null,
+          other: undefined,
+        },
+        array: [
+          {
+            id: 1,
+            createdAt: date1,
+          },
+          {
+            id: 2,
+            createdAt: date2,
+          },
+        ],
+      }
+
+      const output: TestExpectedType = convertDateFieldsToIsoString(input)
+
+      expect(output).toMatchObject({
+        id: 1,
+        date: date1.toISOString(),
+        value: 'test',
+        code: 100,
+        reason: 'reason',
+        other: {
+          id: 2,
+          value: 'test 2',
+          date: date2.toISOString(),
+          code: 200,
+          reason: null,
+          other: undefined,
+        },
+        array: [
+          {
+            id: 1,
+            createdAt: date1.toISOString(),
+          },
+          {
+            id: 2,
+            createdAt: date2.toISOString(),
+          },
+        ],
+      })
+    })
+  })
 })

src/utils/objectUtils.ts

@@ -123,3 +123,35 @@ export function groupByUnique<
     {} as Record<RecordKeyType, T>,
   )
 }
+
+type DatesAsString<T> = T extends Date ? string : ExactlyLikeWithDateAsString<T>
+
+type ExactlyLikeWithDateAsString<T> = T extends object ? { [K in keyof T]: DatesAsString<T[K]> } : T
+
+export function convertDateFieldsToIsoString<Input extends object>(
+  object: Input,
+): ExactlyLikeWithDateAsString<Input>
+export function convertDateFieldsToIsoString<Input extends object>(
+  object: Input[],
+): ExactlyLikeWithDateAsString<Input>[]
+export function convertDateFieldsToIsoString<Input extends object>(
+  object: Input | Input[],
+): ExactlyLikeWithDateAsString<Input> | ExactlyLikeWithDateAsString<Input>[] {
+  if (Array.isArray(object)) {
+    return object.map((item) => convertDateFieldsToIsoString(item))
+  }
+
+  return Object.entries(object).reduce((result, [key, value]) => {
+    if (value instanceof Date) {
+      // @ts-ignore
+      result[key] = value.toISOString()
+    } else if (value && typeof value === 'object') {
+      // @ts-ignore
+      result[key] = convertDateFieldsToIsoString(value)
+    } else {
+      // @ts-ignore
+      result[key] = value
+    }
+    return result
+  }, {} as ExactlyLikeWithDateAsString<Input>)
+}