summaryrefslogtreecommitdiff
path: root/ext/node/polyfills/_fs/_fs_readlink.ts
blob: 5f231279826fdf1a6f4ef384679cbca65da40870 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.

// TODO(petamoriken): enable prefer-primordials for node polyfills
// deno-lint-ignore-file prefer-primordials

import { TextEncoder } from "ext:deno_web/08_text_encoding.js";
import {
  intoCallbackAPIWithIntercept,
  MaybeEmpty,
  notImplemented,
} from "ext:deno_node/_utils.ts";
import { pathFromURL } from "ext:deno_web/00_infra.js";
import { promisify } from "ext:deno_node/internal/util.mjs";

type ReadlinkCallback = (
  err: MaybeEmpty<Error>,
  linkString: MaybeEmpty<string | Uint8Array>,
) => void;

interface ReadlinkOptions {
  encoding?: string | null;
}

function maybeEncode(
  data: string,
  encoding: string | null,
): string | Uint8Array {
  if (encoding === "buffer") {
    return new TextEncoder().encode(data);
  }
  return data;
}

function getEncoding(
  optOrCallback?: ReadlinkOptions | ReadlinkCallback,
): string | null {
  if (!optOrCallback || typeof optOrCallback === "function") {
    return null;
  } else {
    if (optOrCallback.encoding) {
      if (
        optOrCallback.encoding === "utf8" ||
        optOrCallback.encoding === "utf-8"
      ) {
        return "utf8";
      } else if (optOrCallback.encoding === "buffer") {
        return "buffer";
      } else {
        notImplemented(`fs.readlink encoding=${optOrCallback.encoding}`);
      }
    }
    return null;
  }
}

export function readlink(
  path: string | URL,
  optOrCallback: ReadlinkCallback | ReadlinkOptions,
  callback?: ReadlinkCallback,
) {
  path = path instanceof URL ? pathFromURL(path) : path;

  let cb: ReadlinkCallback | undefined;
  if (typeof optOrCallback === "function") {
    cb = optOrCallback;
  } else {
    cb = callback;
  }

  const encoding = getEncoding(optOrCallback);

  intoCallbackAPIWithIntercept<string, Uint8Array | string>(
    Deno.readLink,
    (data: string): string | Uint8Array => maybeEncode(data, encoding),
    cb,
    path,
  );
}

export const readlinkPromise = promisify(readlink) as (
  path: string | URL,
  opt?: ReadlinkOptions,
) => Promise<string | Uint8Array>;

export function readlinkSync(
  path: string | URL,
  opt?: ReadlinkOptions,
): string | Uint8Array {
  path = path instanceof URL ? pathFromURL(path) : path;

  return maybeEncode(Deno.readLinkSync(path), getEncoding(opt));
}