feat(std/node): fs.writefile / fs.promises.writeFile (#5054)

1 files changed, 65 insertions, 0 deletions

diff --git a/std/node/_fs/_fs_writeFile.ts b/std/node/_fs/_fs_writeFile.ts
new file mode 100644
index 000000000..c9f7fe125
--- /dev/null
+++ b/std/node/_fs/_fs_writeFile.ts
@@ -0,0 +1,65 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import { notImplemented } from "../_utils.ts";
+
+import {
+  WriteFileOptions,
+  CallbackWithError,
+  isFileOptions,
+  getEncoding,
+  getOpenOptions,
+} from "./_fs_common.ts";
+
+export function writeFile(
+  pathOrRid: string | number,
+  data: string | Uint8Array,
+  optOrCallback: string | CallbackWithError | WriteFileOptions | undefined,
+  callback?: CallbackWithError
+): void {
+  const callbackFn: CallbackWithError | undefined =
+    optOrCallback instanceof Function ? optOrCallback : callback;
+  const options: string | WriteFileOptions | undefined =
+    optOrCallback instanceof Function ? undefined : optOrCallback;
+
+  if (!callbackFn) {
+    throw new TypeError("Callback must be a function.");
+  }
+
+  const flag: string | undefined = isFileOptions(options)
+    ? options.flag
+    : undefined;
+
+  const mode: number | undefined = isFileOptions(options)
+    ? options.mode
+    : undefined;
+
+  const encoding = getEncoding(options) || "utf8";
+  const openOptions = getOpenOptions(flag || "w");
+
+  if (typeof data === "string" && encoding === "utf8")
+    data = new TextEncoder().encode(data) as Uint8Array;
+
+  const isRid = typeof pathOrRid === "number";
+  let file;
+
+  let error: Error | null = null;
+  (async (): Promise<void> => {
+    try {
+      file = isRid
+        ? new Deno.File(pathOrRid as number)
+        : await Deno.open(pathOrRid as string, openOptions);
+
+      if (!isRid && mode) {
+        if (Deno.build.os === "windows") notImplemented(`"mode" on Windows`);
+        await Deno.chmod(pathOrRid as string, mode);
+      }
+
+      await Deno.writeAll(file, data as Uint8Array);
+    } catch (e) {
+      error = e;
+    } finally {
+      // Make sure to close resource
+      if (!isRid && file) file.close();
+      callbackFn(error);
+    }
+  })();
+}