Function pattern

packages/forms/signals/src/api/rules/validation/pattern.ts:31–60

(
  path: SchemaPath<string, SchemaPathRules.Supported, TPathKind>,
  pattern: RegExp | LogicFn<string | undefined, RegExp | undefined, TPathKind>,
  config?: BaseValidatorConfig<string, TPathKind>,
)

 * @publicApi 22.0
 */
export function pattern<TPathKind extends PathKind = PathKind.Root>(
  path: SchemaPath<string, SchemaPathRules.Supported, TPathKind>,
  pattern: RegExp | LogicFn<string | undefined, RegExp | undefined, TPathKind>,
  config?: BaseValidatorConfig<string, TPathKind>,
) {
  const PATTERN_MEMO = metadata(path, createMetadataKey<RegExp | undefined>(), (ctx) => {
    if (config?.when && !config.when(ctx)) {
      return undefined;
    }
    return pattern instanceof RegExp ? pattern : pattern(ctx);
  });
  metadata(path, PATTERN, ({state}) => state.metadata(PATTERN_MEMO)!());
  validate(path, (ctx) => {
    if (isEmpty(ctx.value())) {
      return undefined;
    }
    const pattern = ctx.state.metadata(PATTERN_MEMO)!();
    if (pattern === undefined) {
      return undefined;
    }
    if (!pattern.test(ctx.value())) {
      if (config?.error) {
        return getOption(config.error, ctx);
      } else {
        return patternError(pattern, {message: getOption(config?.message, ctx)});
      }
    }
    return undefined;
  });
}