typia/src/programmers/internal/check_template.ts

Superfast runtime validators with only one line

import ts from "typescript";

import { MetadataTemplate } from "../../schemas/metadata/MetadataTemplate";

import { ICheckEntry } from "../helpers/ICheckEntry";
import { template_to_pattern } from "./template_to_pattern";

/**
 * @internal
 */
export const check_template =
  (templates: MetadataTemplate[]) =>
  (input: ts.Expression): ICheckEntry => {
    // TYPEOF STRING & TAGS
    const conditions: ts.Expression[] = [
      ts.factory.createStrictEquality(
        ts.factory.createStringLiteral("string"),
        ts.factory.createTypeOfExpression(input),
      ),
    ];

    // TEMPLATES
    const internal: ts.Expression[] = templates.map((tpl) =>
      ts.factory.createCallExpression(
        ts.factory.createIdentifier(
          `RegExp(/${template_to_pattern(true)(tpl.row)}/).test`,
        ),
        undefined,
        [input],
      ),
    );
    conditions.push(
      internal.length === 1
        ? internal[0]!
        : internal.reduce((x, y) => ts.factory.createLogicalOr(x, y)),
    );

    // COMBINATION
    return {
      expression: conditions.reduce((x, y) =>
        ts.factory.createLogicalAnd(x, y),
      ),
      conditions: [],
      expected: templates.map((tpl) => tpl.getName()).join(" | "),
    };
  };