feat: add emptyDir for fs modules (#263)

fs/empty_dir.ts

@@ -0,0 +1,52 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+/**
+ * Ensures that a directory is empty.
+ * Deletes directory contents if the directory is not empty.
+ * If the directory does not exist, it is created.
+ * The directory itself is not deleted.
+ * @export
+ * @param {string} dir
+ * @returns {Promise<void>}
+ */
+export async function emptyDir(dir: string): Promise<void> {
+  let items: Deno.FileInfo[] = [];
+  try {
+    items = await Deno.readDir(dir);
+  } catch {
+    // if not exist. then create it
+    await Deno.mkdir(dir, true);
+    return;
+  }
+  while (items.length) {
+    const item = items.shift();
+    if (item && item.path) {
+      await Deno.remove(item.path, { recursive: true });
+    }
+  }
+}
+
+/**
+ * Ensures that a directory is empty.
+ * Deletes directory contents if the directory is not empty.
+ * If the directory does not exist, it is created.
+ * The directory itself is not deleted.
+ * @export
+ * @param {string} dir
+ * @returns {void}
+ */
+export function emptyDirSync(dir: string): void {
+  let items: Deno.FileInfo[] = [];
+  try {
+    items = Deno.readDirSync(dir);
+  } catch {
+    // if not exist. then create it
+    Deno.mkdirSync(dir, true);
+    return;
+  }
+  while (items.length) {
+    const item = items.shift();
+    if (item && item.path) {
+      Deno.removeSync(item.path, { recursive: true });
+    }
+  }
+}

fs/empty_dir_test.ts

@@ -0,0 +1,117 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import { test } from "../testing/mod.ts";
+import { assertEquals, assertThrowsAsync } from "../testing/asserts.ts";
+import { emptyDir, emptyDirSync } from "./empty_dir.ts";
+import * as path from "./path/mod.ts";
+
+const testdataDir = path.resolve("fs", "testdata");
+
+test(async function emptyDirIfItNotExist() {
+  const testDir = path.join(testdataDir, "empty_dir_test_1");
+  const testNestDir = path.join(testDir, "nest");
+  // empty a dir which not exist. then it will create new one
+  await emptyDir(testNestDir);
+
+  try {
+    // check the dir
+    const stat = await Deno.stat(testNestDir);
+    assertEquals(stat.isDirectory(), true);
+  } finally {
+    // remove the test dir
+    Deno.remove(testDir, { recursive: true });
+  }
+});
+
+test(function emptyDirSyncIfItNotExist() {
+  const testDir = path.join(testdataDir, "empty_dir_test_2");
+  const testNestDir = path.join(testDir, "nest");
+  // empty a dir which not exist. then it will create new one
+  emptyDirSync(testNestDir);
+
+  try {
+    // check the dir
+    const stat = Deno.statSync(testNestDir);
+    assertEquals(stat.isDirectory(), true);
+  } finally {
+    // remove the test dir
+    Deno.remove(testDir, { recursive: true });
+  }
+});
+
+test(async function emptyDirIfItExist() {
+  const testDir = path.join(testdataDir, "empty_dir_test_3");
+  const testNestDir = path.join(testDir, "nest");
+  // create test dir
+  await emptyDir(testNestDir);
+  const testDirFile = path.join(testNestDir, "test.ts");
+  // create test file in test dir
+  await Deno.writeFile(testDirFile, new Uint8Array());
+
+  // before empty: make sure file/directory exist
+  const beforeFileStat = await Deno.stat(testDirFile);
+  assertEquals(beforeFileStat.isFile(), true);
+
+  const beforeDirStat = await Deno.stat(testNestDir);
+  assertEquals(beforeDirStat.isDirectory(), true);
+
+  await emptyDir(testDir);
+
+  // after empty: file/directory have already remove
+  try {
+    // test dir still there
+    const stat = await Deno.stat(testDir);
+    assertEquals(stat.isDirectory(), true);
+
+    // nest directory have been remove
+    assertThrowsAsync(async () => {
+      await Deno.stat(testNestDir);
+    });
+
+    // test file have been remove
+    assertThrowsAsync(async () => {
+      await Deno.stat(testDirFile);
+    });
+  } finally {
+    // remote test dir
+    await Deno.remove(testDir, { recursive: true });
+  }
+});
+
+test(function emptyDirSyncIfItExist() {
+  const testDir = path.join(testdataDir, "empty_dir_test_4");
+  const testNestDir = path.join(testDir, "nest");
+  // create test dir
+  emptyDirSync(testNestDir);
+  const testDirFile = path.join(testNestDir, "test.ts");
+  // create test file in test dir
+  Deno.writeFileSync(testDirFile, new Uint8Array());
+
+  // before empty: make sure file/directory exist
+  const beforeFileStat = Deno.statSync(testDirFile);
+  assertEquals(beforeFileStat.isFile(), true);
+
+  const beforeDirStat = Deno.statSync(testNestDir);
+  assertEquals(beforeDirStat.isDirectory(), true);
+
+  emptyDirSync(testDir);
+
+  // after empty: file/directory have already remove
+  try {
+    // test dir still there
+    const stat = Deno.statSync(testDir);
+    assertEquals(stat.isDirectory(), true);
+
+    // nest directory have been remove
+    assertThrowsAsync(async () => {
+      Deno.statSync(testNestDir);
+    });
+
+    // test file have been remove
+    assertThrowsAsync(async () => {
+      Deno.statSync(testDirFile);
+    });
+  } finally {
+    // remote test dir
+    Deno.removeSync(testDir, { recursive: true });
+  }
+});

test.ts

@@ -15,6 +15,7 @@ import "./fs/walk_test.ts";
 import "./fs/globrex_test.ts";
 import "./fs/glob_test.ts";
 import "./fs/exists_test.ts";
+import "./fs/empty_dir_test.ts";
 import "./io/test.ts";
 import "./http/server_test.ts";
 import "./http/file_server_test.ts";