平台特定的注意事项

在 Windows 上，带有主机名的 file: <URL> 转换为 UNC 路径，而带有驱动器号的 file: <URL> 则转换为本地绝对路径。 没有主机名也没有驱动器号的 file: <URL> 会导致错误：

import { readFileSync } from 'fs';
// 在 Windows 上：

// - 带有主机名的 WHATWG 文件 URL 转换为 UNC 路径
// file://hostname/p/a/t/h/file => \\hostname\p\a\t\h\file
readFileSync(new URL('file://hostname/p/a/t/h/file'));

// - 带有驱动器号的 WHATWG 文件 URL 转换为绝对路径
// file:///C:/tmp/hello => C:\tmp\hello
readFileSync(new URL('file:///C:/tmp/hello'));

// - 没有主机名的 WHATWG 文件 URL 必须有驱动器号
readFileSync(new URL('file:///notdriveletter/p/a/t/h/file'));
readFileSync(new URL('file:///c/p/a/t/h/file'));
// TypeError [ERR_INVALID_FILE_URL_PATH]: File URL path must be absolute

带有驱动器号的 file: <URL> 必须在驱动器号之后使用 : 作为分隔符。 使用其他分隔符会导致错误。

在所有其他平台上，不支持带有主机名的 file: <URL> 并且会导致错误：

import { readFileSync } from 'fs';
// 在其他平台上：

// - 不支持带有主机名的 WHATWG 文件 URL
// file://hostname/p/a/t/h/file => throw!
readFileSync(new URL('file://hostname/p/a/t/h/file'));
// TypeError [ERR_INVALID_FILE_URL_PATH]: must be absolute

// - WHATWG 文件 URL 转换为绝对路径
// file:///tmp/hello => /tmp/hello
readFileSync(new URL('file:///tmp/hello'));

具有编码斜杠字符的 file: <URL> 在所有平台上都将导致错误：

import { readFileSync } from 'fs';

// 在 Windows 上
readFileSync(new URL('file:///C:/p/a/t/h/%2F'));
readFileSync(new URL('file:///C:/p/a/t/h/%2f'));
/* TypeError [ERR_INVALID_FILE_URL_PATH]: File URL path must not include encoded
\ or / characters */

// 在 POSIX 上
readFileSync(new URL('file:///p/a/t/h/%2F'));
readFileSync(new URL('file:///p/a/t/h/%2f'));
/* TypeError [ERR_INVALID_FILE_URL_PATH]: File URL path must not include encoded
/ characters */

在 Windows 上，带有编码反斜杠的 file: <URL> 将导致错误：

import { readFileSync } from 'fs';

// 在 Windows 上
readFileSync(new URL('file:///C:/path/%5C'));
readFileSync(new URL('file:///C:/path/%5c'));
/* TypeError [ERR_INVALID_FILE_URL_PATH]: File URL path must not include encoded
\ or / characters */

On Windows, file: <URL>s with a host name convert to UNC paths, while file: <URL>s with drive letters convert to local absolute paths. file: <URL>s without a host name nor a drive letter will result in an error:

import { readFileSync } from 'fs';
// On Windows :

// - WHATWG file URLs with hostname convert to UNC path
// file://hostname/p/a/t/h/file => \\hostname\p\a\t\h\file
readFileSync(new URL('file://hostname/p/a/t/h/file'));

// - WHATWG file URLs with drive letters convert to absolute path
// file:///C:/tmp/hello => C:\tmp\hello
readFileSync(new URL('file:///C:/tmp/hello'));

// - WHATWG file URLs without hostname must have a drive letters
readFileSync(new URL('file:///notdriveletter/p/a/t/h/file'));
readFileSync(new URL('file:///c/p/a/t/h/file'));
// TypeError [ERR_INVALID_FILE_URL_PATH]: File URL path must be absolute

file: <URL>s with drive letters must use : as a separator just after the drive letter. Using another separator will result in an error.

On all other platforms, file: <URL>s with a host name are unsupported and will result in an error:

import { readFileSync } from 'fs';
// On other platforms:

// - WHATWG file URLs with hostname are unsupported
// file://hostname/p/a/t/h/file => throw!
readFileSync(new URL('file://hostname/p/a/t/h/file'));
// TypeError [ERR_INVALID_FILE_URL_PATH]: must be absolute

// - WHATWG file URLs convert to absolute path
// file:///tmp/hello => /tmp/hello
readFileSync(new URL('file:///tmp/hello'));

A file: <URL> having encoded slash characters will result in an error on all platforms:

import { readFileSync } from 'fs';

// On Windows
readFileSync(new URL('file:///C:/p/a/t/h/%2F'));
readFileSync(new URL('file:///C:/p/a/t/h/%2f'));
/* TypeError [ERR_INVALID_FILE_URL_PATH]: File URL path must not include encoded
\ or / characters */

// On POSIX
readFileSync(new URL('file:///p/a/t/h/%2F'));
readFileSync(new URL('file:///p/a/t/h/%2f'));
/* TypeError [ERR_INVALID_FILE_URL_PATH]: File URL path must not include encoded
/ characters */

On Windows, file: <URL>s having encoded backslash will result in an error:

import { readFileSync } from 'fs';

// On Windows
readFileSync(new URL('file:///C:/path/%5C'));
readFileSync(new URL('file:///C:/path/%5c'));
/* TypeError [ERR_INVALID_FILE_URL_PATH]: File URL path must not include encoded
\ or / characters */