Zod schemas for bcp47 tag validation. Supports both tags and subtags.

bcp47-zod-schemas.ts

import { isValid as isValidLanguageCode } from "@aleksejdix/ally-bcp47"
import { isError } from "remeda"
import { array, preprocess, string } from "zod"

/**
 * All inline localization strings must be written in English.
 * Do not change this type, as it enforces the rule.
 */
type SourceLocaleId = "en"

export const SOURCE_LOCALE_ID: SourceLocaleId = "en"

export type LocaleIdArraySchemaParams = {
  defaultValue: string[]
}

export const localeIdArray = (
  { defaultValue }: LocaleIdArraySchemaParams | undefined = { defaultValue: ["en"] },
) =>
  array(string(), "Must be an array of language code strings")
    .default(defaultValue)
    .refine(
      (values: string[]) => values.every(isValidLanguageCode),
      "Each locale id must be a valid BCP-47 language code",
    )
    .refine(
      (values: string[]) => values.includes(SOURCE_LOCALE_ID),
      "Must contain the source locale ID",
    )

export type LocaleIdJsonArraySchemaParams = {
  default: LocaleIdArraySchemaParams["defaultValue"]
}

export const localeIdJsonArray = (params: LocaleIdJsonArraySchemaParams) =>
  preprocess(
    (value: string | undefined, ctx) => {
      if (typeof value === "string") {
        try {
          return JSON.parse(value) as object
        } catch (err) {
          ctx.issues.push({
            code: "custom",
            message: isError(err) ? err.message : "Invalid JSON",
            input: value,
          })

          return undefined
        }
      } else return undefined
    },

    localeIdArray({ defaultValue: params.default }),
  )