1 files changed, 108 insertions, 0 deletions
diff --git a/ext/node/polyfills/_fs/_fs_readFile.ts b/ext/node/polyfills/_fs/_fs_readFile.ts
new file mode 100644
index 000000000..6c5e9fb8b
--- /dev/null
+++ b/ext/node/polyfills/_fs/_fs_readFile.ts
@@ -0,0 +1,108 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+import {
+  BinaryOptionsArgument,
+  FileOptionsArgument,
+  getEncoding,
+  TextOptionsArgument,
+} from "internal:deno_node/polyfills/_fs/_fs_common.ts";
+import { Buffer } from "internal:deno_node/polyfills/buffer.ts";
+import { fromFileUrl } from "internal:deno_node/polyfills/path.ts";
+import {
+  BinaryEncodings,
+  Encodings,
+  TextEncodings,
+} from "internal:deno_node/polyfills/_utils.ts";
+import { promisify } from "internal:deno_node/polyfills/internal/util.mjs";
+
+function maybeDecode(data: Uint8Array, encoding: TextEncodings): string;
+function maybeDecode(
+  data: Uint8Array,
+  encoding: BinaryEncodings | null,
+): Buffer;
+function maybeDecode(
+  data: Uint8Array,
+  encoding: Encodings | null,
+): string | Buffer {
+  const buffer = Buffer.from(data.buffer, data.byteOffset, data.byteLength);
+  if (encoding && encoding !== "binary") return buffer.toString(encoding);
+  return buffer;
+}
+
+type TextCallback = (err: Error | null, data?: string) => void;
+type BinaryCallback = (err: Error | null, data?: Buffer) => void;
+type GenericCallback = (err: Error | null, data?: string | Buffer) => void;
+type Callback = TextCallback | BinaryCallback | GenericCallback;
+
+export function readFile(
+  path: string | URL,
+  options: TextOptionsArgument,
+  callback: TextCallback,
+): void;
+export function readFile(
+  path: string | URL,
+  options: BinaryOptionsArgument,
+  callback: BinaryCallback,
+): void;
+export function readFile(
+  path: string | URL,
+  options: null | undefined | FileOptionsArgument,
+  callback: BinaryCallback,
+): void;
+export function readFile(path: string | URL, callback: BinaryCallback): void;
+export function readFile(
+  path: string | URL,
+  optOrCallback?: FileOptionsArgument | Callback | null | undefined,
+  callback?: Callback,
+) {
+  path = path instanceof URL ? fromFileUrl(path) : path;
+  let cb: Callback | undefined;
+  if (typeof optOrCallback === "function") {
+    cb = optOrCallback;
+  } else {
+    cb = callback;
+  }
+
+  const encoding = getEncoding(optOrCallback);
+
+  const p = Deno.readFile(path);
+
+  if (cb) {
+    p.then((data: Uint8Array) => {
+      if (encoding && encoding !== "binary") {
+        const text = maybeDecode(data, encoding);
+        return (cb as TextCallback)(null, text);
+      }
+      const buffer = maybeDecode(data, encoding);
+      (cb as BinaryCallback)(null, buffer);
+    }, (err) => cb && cb(err));
+  }
+}
+
+export const readFilePromise = promisify(readFile) as (
+  & ((path: string | URL, opt: TextOptionsArgument) => Promise<string>)
+  & ((path: string | URL, opt?: BinaryOptionsArgument) => Promise<Buffer>)
+  & ((path: string | URL, opt?: FileOptionsArgument) => Promise<Buffer>)
+);
+
+export function readFileSync(
+  path: string | URL,
+  opt: TextOptionsArgument,
+): string;
+export function readFileSync(
+  path: string | URL,
+  opt?: BinaryOptionsArgument,
+): Buffer;
+export function readFileSync(
+  path: string | URL,
+  opt?: FileOptionsArgument,
+): string | Buffer {
+  path = path instanceof URL ? fromFileUrl(path) : path;
+  const data = Deno.readFileSync(path);
+  const encoding = getEncoding(opt);
+  if (encoding && encoding !== "binary") {
+    const text = maybeDecode(data, encoding);
+    return text;
+  }
+  const buffer = maybeDecode(data, encoding);
+  return buffer;
+}