/
_fs_readFile.ts
80 lines (70 loc) · 1.75 KB
/
_fs_readFile.ts
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
// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
import {
notImplemented,
intoCallbackAPIWithIntercept,
MaybeEmpty,
} from "../_utils.ts";
const { readFile: denoReadFile, readFileSync: denoReadFileSync } = Deno;
type ReadFileCallback = (
err: MaybeEmpty<Error>,
data: MaybeEmpty<string | Uint8Array>
) => void;
interface ReadFileOptions {
encoding?: string | null;
flag?: string;
}
function getEncoding(
optOrCallback?: ReadFileOptions | ReadFileCallback
): 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();
}
}
return null;
}
}
function maybeDecode(
data: Uint8Array,
encoding: string | null
): string | Uint8Array {
if (encoding === "utf8") {
return new TextDecoder().decode(data);
}
return data;
}
export function readFile(
path: string,
optOrCallback: ReadFileCallback | ReadFileOptions,
callback?: ReadFileCallback
): void {
let cb: ReadFileCallback | undefined;
if (typeof optOrCallback === "function") {
cb = optOrCallback;
} else {
cb = callback;
}
const encoding = getEncoding(optOrCallback);
intoCallbackAPIWithIntercept<Uint8Array, string | Uint8Array>(
denoReadFile,
(data: Uint8Array): string | Uint8Array => maybeDecode(data, encoding),
cb,
path
);
}
export function readFileSync(
path: string,
opt?: ReadFileOptions
): string | Uint8Array {
return maybeDecode(denoReadFileSync(path), getEncoding(opt));
}