bun.sh/test/js/bun/dns/resolve-dns.test.ts

import { SystemError, dns } from "bun";
import { describe, expect, test } from "bun:test";
import { isWindows, withoutAggressiveGC } from "harness";
import { isIP, isIPv4, isIPv6 } from "node:net";

const backends = ["system", "libc", "c-ares"];
const validHostnames = ["localhost", "example.com"];
const invalidHostnames = ["adsfa.asdfasdf.asdf.com"]; // known invalid
const malformedHostnames = [" ", ".", " .", "localhost:80", "this is not a hostname"];

describe("dns", () => {
  describe.each(backends)("lookup() [backend: %s]", backend => {
    describe.each(validHostnames)("%s", hostname => {
      test.each([
        {
          options: { backend },
          address: isIP,
        },
        {
          options: { backend, family: 4 },
          address: isIPv4,
          family: 4,
        },
        {
          options: { backend, family: "IPv4" },
          address: isIPv4,
          family: 4,
        },
        {
          options: { backend, family: 6 },
          address: isIPv6,
          family: 6,
        },
        {
          options: { backend, family: "IPv6" },
          address: isIPv6,
          family: 6,
        },
        {
          options: { backend, family: 0 },
          address: isIP,
        },
        {
          options: { backend, family: "any" },
          address: isIP,
        },
      ])("%j", async ({ options, address: expectedAddress, family: expectedFamily }) => {
        // this behavior matchs nodejs
        const expect_to_fail =
          isWindows &&
          backend !== "c-ares" &&
          (options.family === "IPv6" || options.family === 6) &&
          hostname !== "localhost";
        if (expect_to_fail) {
          try {
            // @ts-expect-error
            await dns.lookup(hostname, options);
            expect.unreachable();
          } catch (err: unknown) {
            expect(err).toBeDefined();
            expect((err as SystemError).code).toBe("DNS_ENOTFOUND");
          }
          return;
        }
        // @ts-expect-error
        const result = await dns.lookup(hostname, options);
        expect(result).toBeArray();
        expect(result.length).toBeGreaterThan(0);
        withoutAggressiveGC(() => {
          for (const { family, address, ttl } of result) {
            expect(address).toBeString();
            expect(expectedAddress(address)).toBeTruthy();
            expect(family).toBeInteger();
            if (expectedFamily !== undefined) {
              expect(family).toBe(expectedFamily);
            }
            expect(ttl).toBeInteger();
          }
        });
      });
    });
    test.each(validHostnames)("%s [parallel x 10]", async hostname => {
      const results = await Promise.all(
        // @ts-expect-error
        Array.from({ length: 10 }, () => dns.lookup(hostname, { backend })),
      );
      const answers = results.flat();
      expect(answers).toBeArray();
      expect(answers.length).toBeGreaterThanOrEqual(10);
      withoutAggressiveGC(() => {
        for (const { family, address, ttl } of answers) {
          expect(address).toBeString();
          expect(isIP(address)).toBeTruthy();
          expect(family).toBeInteger();
          expect(ttl).toBeInteger();
        }
      });
    });
    test.each(invalidHostnames)("%s", hostname => {
      // @ts-expect-error
      expect(dns.lookup(hostname, { backend })).rejects.toMatchObject({
        code: "DNS_ENOTFOUND",
        name: "DNSException",
      });
    });

    test.each(malformedHostnames)("'%s'", hostname => {
      // @ts-expect-error
      expect(dns.lookup(hostname, { backend })).rejects.toMatchObject({
        code: expect.stringMatching(/^DNS_ENOTFOUND|DNS_ESERVFAIL|DNS_ENOTIMP$/),
        name: "DNSException",
      });
    });
  });
});