1 files changed, 116 insertions, 0 deletions
diff --git a/tests/unit_node/fs_test.ts b/tests/unit_node/fs_test.ts
new file mode 100644
index 000000000..e0cdf3a23
--- /dev/null
+++ b/tests/unit_node/fs_test.ts
@@ -0,0 +1,116 @@
+// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
+
+import {
+  assert,
+  assertEquals,
+  assertThrows,
+} from "@test_util/std/assert/mod.ts";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import {
+  constants,
+  existsSync,
+  mkdtempSync,
+  promises,
+  readFileSync,
+  writeFileSync,
+} from "node:fs";
+import { constants as fsPromiseConstants, cp } from "node:fs/promises";
+import { pathToAbsoluteFileUrl } from "../unit/test_util.ts";
+
+Deno.test(
+  "[node/fs writeFileSync] write file without option",
+  () => {
+    const data = "Hello";
+    const filename = mkdtempSync(join(tmpdir(), "foo-")) + "/test.txt";
+
+    writeFileSync(filename, data);
+    const dataRead = readFileSync(filename, "utf8");
+
+    assert(dataRead === "Hello");
+  },
+);
+
+Deno.test(
+  "[node/fs writeFileSync] write file with option ASCII",
+  () => {
+    const data = "Hello";
+    const filename = mkdtempSync(join(tmpdir(), "foo-")) + "/test.txt";
+
+    writeFileSync(filename, data, { encoding: "ascii" });
+    const dataRead = readFileSync(filename, "utf8");
+
+    assert(dataRead === "Hello");
+  },
+);
+
+Deno.test(
+  "[node/fs writeFileSync] write file throws error when encoding is not implemented",
+  () => {
+    const data = "Hello";
+    const filename = mkdtempSync(join(tmpdir(), "foo-")) + "/test.txt";
+
+    assertThrows(
+      () => writeFileSync(filename, data, { encoding: "utf16le" }),
+      'The value "utf16le" is invalid for option "encoding"',
+    );
+  },
+);
+
+Deno.test(
+  "[node/fs existsSync] path",
+  { permissions: { read: true } },
+  () => {
+    assert(existsSync("tests/testdata/assets/fixture.json"));
+  },
+);
+
+Deno.test(
+  "[node/fs existsSync] url",
+  { permissions: { read: true } },
+  () => {
+    assert(existsSync(
+      pathToAbsoluteFileUrl("tests/testdata/assets/fixture.json"),
+    ));
+  },
+);
+
+Deno.test(
+  "[node/fs existsSync] no permission",
+  { permissions: { read: false } },
+  () => {
+    assertThrows(() => {
+      existsSync("tests/testdata/assets/fixture.json");
+    }, Deno.errors.PermissionDenied);
+  },
+);
+
+Deno.test(
+  "[node/fs existsSync] not exists",
+  { permissions: { read: true } },
+  () => {
+    assert(!existsSync("bad_filename"));
+  },
+);
+
+Deno.test(
+  "[node/fs/promises constants] is the same as from node:fs",
+  () => {
+    assertEquals(constants, fsPromiseConstants);
+    assertEquals(constants, promises.constants);
+  },
+);
+
+Deno.test(
+  "[node/fs/promises cp] copy file",
+  async () => {
+    const src = mkdtempSync(join(tmpdir(), "foo-")) + "/test.txt";
+    const dest = mkdtempSync(join(tmpdir(), "foo-")) + "/test.txt";
+    writeFileSync(src, "Hello");
+
+    await cp(src, dest);
+
+    const dataRead = readFileSync(dest, "utf8");
+    assert(dataRead === "Hello");
+  },
+);