Move writeFileSync to write_file.ts, add writeFile and tests (#728)

1 files changed, 54 insertions, 0 deletions

diff --git a/js/write_file.ts b/js/write_file.ts
new file mode 100644
index 000000000..60c6ff6ab
--- /dev/null
+++ b/js/write_file.ts
@@ -0,0 +1,54 @@
+// Copyright 2018 the Deno authors. All rights reserved. MIT license.
+import * as fbs from "gen/msg_generated";
+import { flatbuffers } from "flatbuffers";
+import * as dispatch from "./dispatch";
+
+/**
+ * Write a new file, with given filename and data synchronously.
+ *
+ *     import { writeFileSync } from "deno";
+ *
+ *     const encoder = new TextEncoder("utf-8");
+ *     const data = encoder.encode("Hello world\n");
+ *     writeFileSync("hello.txt", data);
+ */
+export function writeFileSync(
+  filename: string,
+  data: Uint8Array,
+  perm = 0o666
+): void {
+  dispatch.sendSync(...req(filename, data, perm));
+}
+
+/**
+ * Write a new file, with given filename and data.
+ *
+ *     import { writeFile } from "deno";
+ *
+ *     const encoder = new TextEncoder("utf-8");
+ *     const data = encoder.encode("Hello world\n");
+ *     await writeFile("hello.txt", data);
+ */
+export async function writeFile(
+  filename: string,
+  data: Uint8Array,
+  perm = 0o666
+): Promise<void> {
+  await dispatch.sendAsync(...req(filename, data, perm));
+}
+
+function req(
+  filename: string,
+  data: Uint8Array,
+  perm: number
+): [flatbuffers.Builder, fbs.Any, flatbuffers.Offset] {
+  const builder = new flatbuffers.Builder();
+  const filename_ = builder.createString(filename);
+  const dataOffset = fbs.WriteFile.createDataVector(builder, data);
+  fbs.WriteFile.startWriteFile(builder);
+  fbs.WriteFile.addFilename(builder, filename_);
+  fbs.WriteFile.addData(builder, dataOffset);
+  fbs.WriteFile.addPerm(builder, perm);
+  const msg = fbs.WriteFile.endWriteFile(builder);
+  return [builder, fbs.Any.WriteFile, msg];
+}