1 files changed, 198 insertions, 0 deletions
diff --git a/ext/node/polyfills/_fs/_fs_open.ts b/ext/node/polyfills/_fs/_fs_open.ts
new file mode 100644
index 000000000..e703da56f
--- /dev/null
+++ b/ext/node/polyfills/_fs/_fs_open.ts
@@ -0,0 +1,198 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+import {
+  O_APPEND,
+  O_CREAT,
+  O_EXCL,
+  O_RDWR,
+  O_TRUNC,
+  O_WRONLY,
+} from "internal:deno_node/polyfills/_fs/_fs_constants.ts";
+import { getOpenOptions } from "internal:deno_node/polyfills/_fs/_fs_common.ts";
+import { promisify } from "internal:deno_node/polyfills/internal/util.mjs";
+import { parseFileMode } from "internal:deno_node/polyfills/internal/validators.mjs";
+import { ERR_INVALID_ARG_TYPE } from "internal:deno_node/polyfills/internal/errors.ts";
+import { getValidatedPath } from "internal:deno_node/polyfills/internal/fs/utils.mjs";
+import type { Buffer } from "internal:deno_node/polyfills/buffer.ts";
+
+function existsSync(filePath: string | URL): boolean {
+  try {
+    Deno.lstatSync(filePath);
+    return true;
+  } catch (error) {
+    if (error instanceof Deno.errors.NotFound) {
+      return false;
+    }
+    throw error;
+  }
+}
+
+const FLAGS_AX = O_APPEND | O_CREAT | O_WRONLY | O_EXCL;
+const FLAGS_AX_PLUS = O_APPEND | O_CREAT | O_RDWR | O_EXCL;
+const FLAGS_WX = O_TRUNC | O_CREAT | O_WRONLY | O_EXCL;
+const FLAGS_WX_PLUS = O_TRUNC | O_CREAT | O_RDWR | O_EXCL;
+
+export type openFlags =
+  | "a"
+  | "ax"
+  | "a+"
+  | "ax+"
+  | "as"
+  | "as+"
+  | "r"
+  | "r+"
+  | "rs+"
+  | "w"
+  | "wx"
+  | "w+"
+  | "wx+"
+  | number;
+
+type openCallback = (err: Error | null, fd: number) => void;
+
+function convertFlagAndModeToOptions(
+  flag?: openFlags,
+  mode?: number,
+): Deno.OpenOptions | undefined {
+  if (!flag && !mode) return undefined;
+  if (!flag && mode) return { mode };
+  return { ...getOpenOptions(flag), mode };
+}
+
+export function open(path: string | Buffer | URL, callback: openCallback): void;
+export function open(
+  path: string | Buffer | URL,
+  flags: openFlags,
+  callback: openCallback,
+): void;
+export function open(
+  path: string | Buffer | URL,
+  flags: openFlags,
+  mode: number,
+  callback: openCallback,
+): void;
+export function open(
+  path: string | Buffer | URL,
+  flags: openCallback | openFlags,
+  mode?: openCallback | number,
+  callback?: openCallback,
+) {
+  if (flags === undefined) {
+    throw new ERR_INVALID_ARG_TYPE(
+      "flags or callback",
+      ["string", "function"],
+      flags,
+    );
+  }
+  path = getValidatedPath(path);
+  if (arguments.length < 3) {
+    // deno-lint-ignore no-explicit-any
+    callback = flags as any;
+    flags = "r";
+    mode = 0o666;
+  } else if (typeof mode === "function") {
+    callback = mode;
+    mode = 0o666;
+  } else {
+    mode = parseFileMode(mode, "mode", 0o666);
+  }
+
+  if (typeof callback !== "function") {
+    throw new ERR_INVALID_ARG_TYPE(
+      "callback",
+      "function",
+      callback,
+    );
+  }
+
+  if (flags === undefined) {
+    flags = "r";
+  }
+
+  if (
+    existenceCheckRequired(flags as openFlags) &&
+    existsSync(path as string)
+  ) {
+    const err = new Error(`EEXIST: file already exists, open '${path}'`);
+    (callback as (err: Error) => void)(err);
+  } else {
+    if (flags === "as" || flags === "as+") {
+      let err: Error | null = null, res: number;
+      try {
+        res = openSync(path, flags, mode);
+      } catch (error) {
+        err = error instanceof Error ? error : new Error("[non-error thrown]");
+      }
+      if (err) {
+        (callback as (err: Error) => void)(err);
+      } else {
+        callback(null, res!);
+      }
+      return;
+    }
+    Deno.open(
+      path as string,
+      convertFlagAndModeToOptions(flags as openFlags, mode),
+    ).then(
+      (file) => callback!(null, file.rid),
+      (err) => (callback as (err: Error) => void)(err),
+    );
+  }
+}
+
+export const openPromise = promisify(open) as (
+  & ((path: string | Buffer | URL) => Promise<number>)
+  & ((path: string | Buffer | URL, flags: openFlags) => Promise<number>)
+  & ((path: string | Buffer | URL, mode?: number) => Promise<number>)
+  & ((
+    path: string | Buffer | URL,
+    flags?: openFlags,
+    mode?: number,
+  ) => Promise<number>)
+);
+
+export function openSync(path: string | Buffer | URL): number;
+export function openSync(
+  path: string | Buffer | URL,
+  flags?: openFlags,
+): number;
+export function openSync(path: string | Buffer | URL, mode?: number): number;
+export function openSync(
+  path: string | Buffer | URL,
+  flags?: openFlags,
+  mode?: number,
+): number;
+export function openSync(
+  path: string | Buffer | URL,
+  flags?: openFlags,
+  maybeMode?: number,
+) {
+  const mode = parseFileMode(maybeMode, "mode", 0o666);
+  path = getValidatedPath(path);
+
+  if (flags === undefined) {
+    flags = "r";
+  }
+
+  if (
+    existenceCheckRequired(flags) &&
+    existsSync(path as string)
+  ) {
+    throw new Error(`EEXIST: file already exists, open '${path}'`);
+  }
+
+  return Deno.openSync(path as string, convertFlagAndModeToOptions(flags, mode))
+    .rid;
+}
+
+function existenceCheckRequired(flags: openFlags | number) {
+  return (
+    (typeof flags === "string" &&
+      ["ax", "ax+", "wx", "wx+"].includes(flags)) ||
+    (typeof flags === "number" && (
+      ((flags & FLAGS_AX) === FLAGS_AX) ||
+      ((flags & FLAGS_AX_PLUS) === FLAGS_AX_PLUS) ||
+      ((flags & FLAGS_WX) === FLAGS_WX) ||
+      ((flags & FLAGS_WX_PLUS) === FLAGS_WX_PLUS)
+    ))
+  );
+}