typia/src/factories/internal/metadata/iterate_metadata_constant.ts

Superfast runtime validators with only one line

import ts from "typescript";

import { Metadata } from "../../../schemas/metadata/Metadata";
import { MetadataConstant } from "../../../schemas/metadata/MetadataConstant";
import { MetadataConstantValue } from "../../../schemas/metadata/MetadataConstantValue";

import { ArrayUtil } from "../../../utils/ArrayUtil";

import { CommentFactory } from "../../CommentFactory";
import { MetadataFactory } from "../../MetadataFactory";

export const iterate_metadata_constant =
  (checker: ts.TypeChecker) =>
  (options: MetadataFactory.IOptions) =>
  (meta: Metadata, type: ts.Type): boolean => {
    if (!options.constant) return false;

    const filter = (flag: ts.TypeFlags) => (type.getFlags() & flag) !== 0;
    const comment = () => {
      if (!filter(ts.TypeFlags.EnumLiteral)) return {};
      return {
        jsDocTags: type.symbol?.getJsDocTags(),
        description: type.symbol
          ? CommentFactory.description(type.symbol) ?? null
          : undefined,
      };
    };
    if (type.isLiteral()) {
      const value: string | number | bigint =
        typeof type.value === "object"
          ? BigInt(`${type.value.negative ? "-" : ""}${type.value.base10Value}`)
          : type.value;
      const constant: MetadataConstant = ArrayUtil.take(
        meta.constants,
        (elem) => elem.type === typeof value,
        () =>
          MetadataConstant.create({
            type: typeof value as "number",
            values: [],
          }),
      );
      ArrayUtil.add(
        constant.values,
        MetadataConstantValue.create({
          value,
          tags: [],
          ...comment(),
        }),
        (a, b) => a.value === b.value,
      );
      return true;
    } else if (filter(ts.TypeFlags.BooleanLiteral)) {
      comment();
      const value: boolean = checker.typeToString(type) === "true";
      const constant: MetadataConstant = ArrayUtil.take(
        meta.constants,
        (elem) => elem.type === "boolean",
        () =>
          MetadataConstant.create({
            type: "boolean",
            values: [],
          }),
      );
      ArrayUtil.add(
        constant.values,
        MetadataConstantValue.create({
          value,
          tags: [],
          ...comment(),
        }),
        (a, b) => a.value === b.value,
      );
      return true;
    }
    return false;
  };