deno/js/link_test.ts

// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
import { test, testPerm, assert, assertEquals } from "./test_util.ts";

testPerm({ read: true, write: true }, function linkSyncSuccess(): void {
  const testDir = Deno.makeTempDirSync();
  const oldData = "Hardlink";
  const oldName = testDir + "/oldname";
  const newName = testDir + "/newname";
  Deno.writeFileSync(oldName, new TextEncoder().encode(oldData));
  // Create the hard link.
  Deno.linkSync(oldName, newName);
  // We should expect reading the same content.
  const newData = new TextDecoder().decode(Deno.readFileSync(newName));
  assertEquals(oldData, newData);
  // Writing to newname also affects oldname.
  const newData2 = "Modified";
  Deno.writeFileSync(newName, new TextEncoder().encode(newData2));
  assertEquals(newData2, new TextDecoder().decode(Deno.readFileSync(oldName)));
  // Writing to oldname also affects newname.
  const newData3 = "ModifiedAgain";
  Deno.writeFileSync(oldName, new TextEncoder().encode(newData3));
  assertEquals(newData3, new TextDecoder().decode(Deno.readFileSync(newName)));
  // Remove oldname. File still accessible through newname.
  Deno.removeSync(oldName);
  const newNameStat = Deno.statSync(newName);
  assert(newNameStat.isFile());
  assert(!newNameStat.isSymlink()); // Not a symlink.
  assertEquals(newData3, new TextDecoder().decode(Deno.readFileSync(newName)));
});

testPerm({ read: true, write: true }, function linkSyncExists(): void {
  const testDir = Deno.makeTempDirSync();
  const oldName = testDir + "/oldname";
  const newName = testDir + "/newname";
  Deno.writeFileSync(oldName, new TextEncoder().encode("oldName"));
  // newname is already created.
  Deno.writeFileSync(newName, new TextEncoder().encode("newName"));

  let err;
  try {
    Deno.linkSync(oldName, newName);
  } catch (e) {
    err = e;
  }
  assert(!!err);
  assertEquals(err.kind, Deno.ErrorKind.AlreadyExists);
  assertEquals(err.name, "AlreadyExists");
});

testPerm({ read: true, write: true }, function linkSyncNotFound(): void {
  const testDir = Deno.makeTempDirSync();
  const oldName = testDir + "/oldname";
  const newName = testDir + "/newname";

  let err;
  try {
    Deno.linkSync(oldName, newName);
  } catch (e) {
    err = e;
  }
  assert(!!err);
  assertEquals(err.kind, Deno.ErrorKind.NotFound);
  assertEquals(err.name, "NotFound");
});

test(function linkSyncPerm(): void {
  let err;
  try {
    Deno.linkSync("oldbaddir", "newbaddir");
  } catch (e) {
    err = e;
  }
  assertEquals(err.kind, Deno.ErrorKind.PermissionDenied);
  assertEquals(err.name, "PermissionDenied");
});

testPerm({ read: true, write: true }, async function linkSuccess(): Promise<
  void
> {
  const testDir = Deno.makeTempDirSync();
  const oldData = "Hardlink";
  const oldName = testDir + "/oldname";
  const newName = testDir + "/newname";
  Deno.writeFileSync(oldName, new TextEncoder().encode(oldData));
  // Create the hard link.
  await Deno.link(oldName, newName);
  // We should expect reading the same content.
  const newData = new TextDecoder().decode(Deno.readFileSync(newName));
  assertEquals(oldData, newData);
  // Writing to newname also affects oldname.
  const newData2 = "Modified";
  Deno.writeFileSync(newName, new TextEncoder().encode(newData2));
  assertEquals(newData2, new TextDecoder().decode(Deno.readFileSync(oldName)));
  // Writing to oldname also affects newname.
  const newData3 = "ModifiedAgain";
  Deno.writeFileSync(oldName, new TextEncoder().encode(newData3));
  assertEquals(newData3, new TextDecoder().decode(Deno.readFileSync(newName)));
  // Remove oldname. File still accessible through newname.
  Deno.removeSync(oldName);
  const newNameStat = Deno.statSync(newName);
  assert(newNameStat.isFile());
  assert(!newNameStat.isSymlink()); // Not a symlink.
  assertEquals(newData3, new TextDecoder().decode(Deno.readFileSync(newName)));
});