Merge pull request #36842 from overleaf/em-tpds-typescript

Convert third-party-datastore to TypeScript

GitOrigin-RevId: 028172063d0cfe03c0f105f48ab66020c79ea50e

libraries/validation-tools/test/unit/src/zodHelpers.test.ts

@@ -1,10 +1,43 @@
 import { zz } from '../../../zodHelpers'
 import { describe, expect, it } from 'vitest'
 import mongodb from 'mongodb'
+import { z } from 'zod'
 
 const { ObjectId } = mongodb
 
 describe('zodHelpers', () => {
+  describe('optional', () => {
+    it('parses a present value with the wrapped schema', () => {
+      const parsed = zz.optional(z.string()).safeParse('a value')
+      expect(parsed.success).toBe(true)
+      expect(parsed.data).toBe('a value')
+    })
+
+    it('normalises null to undefined', () => {
+      const parsed = zz.optional(z.string()).safeParse(null)
+      expect(parsed.success).toBe(true)
+      expect(parsed.data).toBe(undefined)
+    })
+
+    it('normalises undefined to undefined', () => {
+      const parsed = zz.optional(z.string()).safeParse(undefined)
+      expect(parsed.success).toBe(true)
+      expect(parsed.data).toBe(undefined)
+    })
+
+    it('leaves a null unparsed by the wrapped schema', () => {
+      // A coercing schema would otherwise turn null into a value of its own,
+      // such as the 0 that Number(null) gives.
+      const parsed = zz.optional(z.coerce.number()).safeParse(null)
+      expect(parsed.success).toBe(true)
+      expect(parsed.data).toBe(undefined)
+    })
+
+    it('reports a present value the wrapped schema rejects', () => {
+      const parsed = zz.optional(z.string()).safeParse(7)
+      expect(parsed.success).toBe(false)
+    })
+  })
   describe('objectId', () => {
     it('fails to parse when provided with an invalid ObjectId', () => {
       const parsed = zz.objectId().safeParse('aa')

libraries/validation-tools/zodHelpers.js

@@ -21,6 +21,23 @@ const datetimeSchema = ({ allowNull, allowUndefined, ...zodOptions } = {}) => {
 }
 
 const zz = {
+  /**
+   * A field whose absence its source represents inconsistently: left out of
+   * some records and null in others. JSON has no undefined, and Mongo stores a
+   * $set of undefined as null, so an absent-ish field arrives as null about as
+   * often as it is missing outright.
+   *
+   * Unlike z.optional(), which accepts only undefined, both forms are accepted
+   * and normalised to undefined, so callers have a single absent value to
+   * check rather than a `T | null | undefined` to narrow.
+   *
+   * The one combinator here: it wraps another schema instead of describing a
+   * value type of its own.
+   *
+   * @template Output
+   * @param {z.ZodType<Output>} schema
+   */
+  optional: schema => schema.nullish().transform(value => value ?? undefined),
   objectId: () =>
     z.string().refine(ObjectId.isValid, { message: 'invalid Mongo ObjectId' }),
   coercedObjectId: () =>