Implement DNS module (#1691)

* Boilerplate for DNS stuff

* Add c-ares

* lookup

* make

* Implement dns.lookup

* Create c-ares

* wip

* normalize

* repro

* Revert "repro"

This reverts commit 8b93e0c295b335b8882a9601da47720348549beb.

* Implement macOS `getaddrinfo_async_start`

* embiggen

* Update string_immutable.zig

* Update Makefile

* alright

* Update .gitignore

* Add types

* more ccache

* Update Dockerfile

* Update Dockerfile

* Update Dockerfile

* Update bun.d.ts

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

2 files changed, 54 insertions, 0 deletions

diff --git a/test/bun.js/dns.node.mjs b/test/bun.js/dns.node.mjs
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/test/bun.js/dns.node.mjs
diff --git a/test/bun.js/resolve-dns.test.ts b/test/bun.js/resolve-dns.test.ts
new file mode 100644
index 000000000..f0db49b20
--- /dev/null
+++ b/test/bun.js/resolve-dns.test.ts
@@ -0,0 +1,54 @@
+import { dns } from "bun";
+import { describe, expect, it, test } from "bun:test";
+import { withoutAggressiveGC } from "gc";
+
+describe("dns.lookup", () => {
+  const backends = [
+    process.platform === "darwin" ? "system" : undefined,
+    "libc",
+    "c-ares",
+  ].filter(Boolean);
+  for (let backend of backends) {
+    it(backend + " parallell x 10", async () => {
+      const promises = [];
+      for (let i = 0; i < 10; i++) {
+        promises.push(dns.lookup("localhost", { backend }));
+      }
+      const results = (await Promise.all(promises)).flat();
+      withoutAggressiveGC(() => {
+        for (let { family, address } of results) {
+          if (family === 4) {
+            expect(address).toBe("127.0.0.1");
+          } else if (family === 6) {
+            expect(address).toBe("::1");
+          } else {
+            throw new Error("Unknown family");
+          }
+        }
+      });
+    });
+
+    it(backend + " remote", async () => {
+      const [first, second] = await dns.lookup("google.com", { backend });
+      console.log(first, second);
+    });
+    it(backend + " local", async () => {
+      const [first, second] = await dns.lookup("localhost", { backend });
+      console.log(first, second);
+    });
+
+    it(
+      backend +
+        " failing domain throws an error without taking a very long time",
+      async () => {
+        try {
+          await dns.lookup("yololololololo1234567.com", { backend });
+          throw 42;
+        } catch (e) {
+          expect(typeof e).not.toBe("number");
+          expect(e.code).toBe("DNS_ENOTFOUND");
+        }
+      },
+    );
+  }
+});