jest.config.ts

import tsConfig from "./tsconfig.json";
import { createDefaultPreset } from "ts-jest";
import type { Config } from "@jest/types";
import * as path from "node:path";

interface TsConfigPaths {
  [key: string]: string[];
}

function convertTsConfigPathsToModuleNameMapper(
  paths: TsConfigPaths = {},
): Record<string, string> {
  const moduleNameMapper: Record<string, string> = {};

  for (const [key, value] of Object.entries(paths)) {
    const jestKey = `^${key.replace(/\*/, "(.*)")}$`;
    const jestValue = path.join(
      "<rootDir>",
      "./",
      value[0].replace(/\*/, "$1"),
    );
    moduleNameMapper[jestKey] = jestValue;
  }

  return moduleNameMapper;
}

const defaultPreset = createDefaultPreset();

/** @type {import('ts-jest').JestConfigWithTsJest} */
export default {
  ...defaultPreset,
  testEnvironment: "node",
  extensionsToTreatAsEsm: [".ts", ".tsx"],
  transformIgnorePatterns: ["/node_modules/"],
  reporters: [
    "default",
    ["jest-junit", { outputDirectory: "./coverage", outputName: "junit.xml" }],
  ],
  coverageReporters: ["html", "text", "text-summary", "cobertura"],
  coveragePathIgnorePatterns: [
    "/node_modules/",
    "/src/index.ts",
    "/src/zod/*",
    "/dist/",
    "/types/",
    "/test/arbitrary.ts",
    "/config/",
  ],
  moduleNameMapper: convertTsConfigPathsToModuleNameMapper(
    tsConfig.compilerOptions.paths,
  ),
} as Config.InitialOptions;