feat: add move/moveSync for fs modules (#266)

fs/move.ts

@@ -0,0 +1,88 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+import * as path from "./path/mod.ts";
+import { exists, existsSync } from "./exists.ts";
+
+interface MoveOptions {
+  overwrite?: boolean;
+}
+
+function isSrcSubdir(src: string, dest: string): boolean {
+  const srcArray = src.split(path.sep);
+  const destArray = dest.split(path.sep);
+
+  return srcArray.reduce((acc, current, i) => {
+    return acc && destArray[i] === current;
+  }, true);
+}
+
+/**
+ * Moves a file or directory
+ * @export
+ * @param {string} src
+ * @param {string} dest
+ * @param {MoveOptions} [options]
+ * @returns {Promise<void>}
+ */
+export async function move(
+  src: string,
+  dest: string,
+  options?: MoveOptions
+): Promise<void> {
+  src = path.resolve(src);
+  dest = path.resolve(dest);
+
+  const srcStat = await Deno.stat(src);
+
+  if (srcStat.isDirectory() && isSrcSubdir(src, dest)) {
+    throw new Error(
+      `Cannot move '${src}' to a subdirectory of itself, '${dest}'.`
+    );
+  }
+
+  if (options && options.overwrite) {
+    await Deno.remove(dest, { recursive: true });
+    await Deno.rename(src, dest);
+  } else {
+    if (await exists(dest)) {
+      throw new Error("dest already exists.");
+    }
+    await Deno.rename(src, dest);
+  }
+
+  return;
+}
+
+/**
+ * Moves a file or directory
+ * @export
+ * @param {string} src
+ * @param {string} dest
+ * @param {MoveOptions} [options]
+ * @returns {void}
+ */
+export function moveSync(
+  src: string,
+  dest: string,
+  options?: MoveOptions
+): void {
+  src = path.resolve(src);
+  dest = path.resolve(dest);
+
+  const srcStat = Deno.statSync(src);
+
+  if (srcStat.isDirectory() && isSrcSubdir(src, dest)) {
+    throw new Error(
+      `Cannot move '${src}' to a subdirectory of itself, '${dest}'.`
+    );
+  }
+
+  if (options && options.overwrite) {
+    Deno.removeSync(dest, { recursive: true });
+    Deno.renameSync(src, dest);
+  } else {
+    if (existsSync(dest)) {
+      throw new Error("dest already exists.");
+    }
+    Deno.renameSync(src, dest);
+  }
+}