53 lines
1.3 KiB
Plaintext
53 lines
1.3 KiB
Plaintext
// 'mime-score' back-ported to CommonJS
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// Score RFC facets (see https://tools.ietf.org/html/rfc6838#section-3)
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var FACET_SCORES = {
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'prs.': 100,
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'x-': 200,
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'x.': 300,
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'vnd.': 400,
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default: 900
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}
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// Score mime source (Logic originally from `jshttp/mime-types` module)
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var SOURCE_SCORES = {
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nginx: 10,
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apache: 20,
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iana: 40,
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default: 30 // definitions added by `jshttp/mime-db` project?
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}
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var TYPE_SCORES = {
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// prefer application/xml over text/xml
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// prefer application/rtf over text/rtf
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application: 1,
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// prefer font/woff over application/font-woff
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font: 2,
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default: 0
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}
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/**
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* Get each component of the score for a mime type. The sum of these is the
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* total score. The higher the score, the more "official" the type.
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*/
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module.exports = function mimeScore (mimeType, source = 'default') {
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if (mimeType === 'application/octet-stream') {
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return 0
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}
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const [type, subtype] = mimeType.split('/')
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const facet = subtype.replace(/(\.|x-).*/, '$1')
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const facetScore = FACET_SCORES[facet] || FACET_SCORES.default
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const sourceScore = SOURCE_SCORES[source] || SOURCE_SCORES.default
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const typeScore = TYPE_SCORES[type] || TYPE_SCORES.default
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// All else being equal prefer shorter types
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const lengthScore = 1 - mimeType.length / 100
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return facetScore + sourceScore + typeScore + lengthScore
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}
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