mime.js

const path = require('path')
const mimeTypes = 类型 json;
module.exports = (filePath) => {
    let ext = path.extname(filePath)
        .split('.')
        .pop()
        .toLowerCase();
    if (!ext) {
        ext = filePath
    }
    return mimeTypes[ext] || mimeTypes['txt']
}

### 使用
mime(文件名)

mimeType

const mimeTypes = {
  '323':    'text/h323',
  'acx':    'application/internet-property-stream',
  'ai':     'application/postscript',
  'aif':    'audio/x-aiff',
  'aifc':   'audio/x-aiff',
  'aiff':   'audio/x-aiff',
  'asf':    'video/x-ms-asf',
  'asr':    'video/x-ms-asf',
  'asx':    'video/x-ms-asf',
  'au':     'audio/basic',
  'avi':    'video/x-msvideo',
  'axs':    'application/olescript',
  'bas':    'text/plain',
  'bcpio':  'application/x-bcpio',
  'bin':    'application/octet-stream',
  'bmp':    'image/bmp',
  'c':      'text/plain',
  'cat':    'application/vnd.ms-pkiseccat',
  'cdf':    'application/x-cdf',
  'cer':    'application/x-x509-ca-cert',
  'class':  'application/octet-stream',
  'clp':    'application/x-msclip',
  'cmx':    'image/x-cmx',
  'cod':    'image/cis-cod',
  'cpio':   'application/x-cpio',
  'crd':    'application/x-mscardfile',
  'crl':    'application/pkix-crl',
  'crt':    'application/x-x509-ca-cert',
  'csh':    'application/x-csh',
  'css':    'text/css',
  'dcr':    'application/x-director',
  'der':    'application/x-x509-ca-cert',
  'dir':    'application/x-director',
  'dll':    'application/x-msdownload',
  'dms':    'application/octet-stream',
  'doc':    'application/msword',
  'dot':    'application/msword',
  'dvi':    'application/x-dvi',
  'dxr':    'application/x-director',
  'eps':    'application/postscript',
  'etx':    'text/x-setext',
  'evy':    'application/envoy',
  'exe':    'application/octet-stream',
  'fif':    'application/fractals',
  'flr':    'x-world/x-vrml',
  'gif':    'image/gif',
  'gtar':   'application/x-gtar',
  'gz':     'application/x-gzip',
  'h':      'text/plain',
  'hdf':    'application/x-hdf',
  'hlp':    'application/winhlp',
  'hqx':    'application/mac-binhex40',
  'hta':    'application/hta',
  'htc':    'text/x-component',
  'htm':    'text/html',
  'html':   'text/html',
  'htt':    'text/webviewhtml',
  'ico':    'image/x-icon',
  'ief':    'image/ief',
  'iii':    'application/x-iphone',
  'ins':    'application/x-internet-signup',
  'isp':    'application/x-internet-signup',
  'jfif':   'image/pipeg',
  'jpe':    'image/jpeg',
  'jpeg':   'image/jpeg',
  'jpg':    'image/jpeg',
  'js':     'application/x-javascript',
  'latex':  'application/x-latex',
  'lha':    'application/octet-stream',
  'lsf':    'video/x-la-asf',
  'lsx':    'video/x-la-asf',
  'lzh':    'application/octet-stream',
  'm13':    'application/x-msmediaview',
  'm14':    'application/x-msmediaview',
  'm3u':    'audio/x-mpegurl',
  'man':    'application/x-troff-man',
  'mdb':    'application/x-msaccess',
  'me':     'application/x-troff-me',
  'mht':    'message/rfc822',
  'mhtml':  'message/rfc822',
  'mid':    'audio/mid',
  'mny':    'application/x-msmoney',
  'mov':    'video/quicktime',
  'movie':  'video/x-sgi-movie',
  'mp2':    'video/mpeg',
  'mp3':    'audio/mpeg',
  'mpa':    'video/mpeg',
  'mpe':    'video/mpeg',
  'mpeg':   'video/mpeg',
  'mpg':    'video/mpeg',
  'mpp':    'application/vnd.ms-project',
  'mpv2':   'video/mpeg',
  'ms':     'application/x-troff-ms',
  'mvb':    'application/x-msmediaview',
  'nws':    'message/rfc822',
  'oda':    'application/oda',
  'p10':    'application/pkcs10',
  'p12':    'application/x-pkcs12',
  'p7b':    'application/x-pkcs7-certificates',
  'p7c':    'application/x-pkcs7-mime',
  'p7m':    'application/x-pkcs7-mime',
  'p7r':    'application/x-pkcs7-certreqresp',
  'p7s':    'application/x-pkcs7-signature',
  'pbm':    'image/x-portable-bitmap',
  'pdf':    'application/pdf',
  'pfx':    'application/x-pkcs12',
  'pgm':    'image/x-portable-graymap',
  'pko':    'application/ynd.ms-pkipko',
  'pma':    'application/x-perfmon',
  'pmc':    'application/x-perfmon',
  'pml':    'application/x-perfmon',
  'pmr':    'application/x-perfmon',
  'pmw':    'application/x-perfmon',
  'pnm':    'image/x-portable-anymap',
  'pot,':   'application/vnd.ms-powerpoint',
  'ppm':    'image/x-portable-pixmap',
  'pps':    'application/vnd.ms-powerpoint',
  'ppt':    'application/vnd.ms-powerpoint',
  'prf':    'application/pics-rules',
  'ps':     'application/postscript',
  'pub':    'application/x-mspublisher',
  'qt':     'video/quicktime',
  'ra':     'audio/x-pn-realaudio',
  'ram':    'audio/x-pn-realaudio',
  'ras':    'image/x-cmu-raster',
  'rgb':    'image/x-rgb',
  'rmi':    'audio/mid',
  'roff':   'application/x-troff',
  'rtf':    'application/rtf',
  'rtx':    'text/richtext',
  'scd':    'application/x-msschedule',
  'sct':    'text/scriptlet',
  'setpay': 'application/set-payment-initiation',
  'setreg': 'application/set-registration-initiation',
  'sh':     'application/x-sh',
  'shar':   'application/x-shar',
  'sit':    'application/x-stuffit',
  'snd':    'audio/basic',
  'spc':    'application/x-pkcs7-certificates',
  'spl':    'application/futuresplash',
  'src':    'application/x-wais-source',
  'sst':    'application/vnd.ms-pkicertstore',
  'stl':    'application/vnd.ms-pkistl',
  'stm':    'text/html',
  'svg':    'image/svg+xml',
  'sv4cpio':    'application/x-sv4cpio',
  'sv4crc': 'application/x-sv4crc',
  'swf':    'application/x-shockwave-flash',
  't':      'application/x-troff',
  'tar':    'application/x-tar',
  'tcl':    'application/x-tcl',
  'tex':    'application/x-tex',
  'texi':   'application/x-texinfo',
  'texinfo':    'application/x-texinfo',
  'tgz':    'application/x-compressed',
  'tif':    'image/tiff',
  'tiff':   'image/tiff',
  'tr':     'application/x-troff',
  'trm':    'application/x-msterminal',
  'tsv':    'text/tab-separated-values',
  'txt':    'text/plain',
  'uls':    'text/iuls',
  'ustar':  'application/x-ustar',
  'vcf':    'text/x-vcard',
  'vrml':   'x-world/x-vrml',
  'wav':    'audio/x-wav',
  'wcm':    'application/vnd.ms-works',
  'wdb':    'application/vnd.ms-works',
  'wks':    'application/vnd.ms-works',
  'wmf':    'application/x-msmetafile',
  'wps':    'application/vnd.ms-works',
  'wri':    'application/x-mswrite',
  'wrl':    'x-world/x-vrml',
  'wrz':    'x-world/x-vrml',
  'xaf':    'x-world/x-vrml',
  'xbm':    'image/x-xbitmap',
  'xla':    'application/vnd.ms-excel',
  'xlc':    'application/vnd.ms-excel',
  'xlm':    'application/vnd.ms-excel',
  'xls':    'application/vnd.ms-excel',
  'xlt':    'application/vnd.ms-excel',
  'xlw':    'application/vnd.ms-excel',
  'xof':    'x-world/x-vrml',
  'xpm':    'image/x-xpixmap',
  'xwd':    'image/x-xwindowdump',
  'z':      'application/x-compress',
  'zip':    'application/zip'
}