forked from wgroeneveld/go-jamming
38 lines
969 B
JavaScript
38 lines
969 B
JavaScript
const got = require('got')
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const { mf2 } = require("microformats-parser");
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const baseUrlOf = (url) => {
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if(url.match(/\//g).length <= 2) {
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return url
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}
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const split = url.split('/')
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return split[0] + '//' + split[2]
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}
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// see https://www.w3.org/TR/webmention/#sender-discovers-receiver-webmention-endpoint
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async function discover(target) {
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try {
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const endpoint = await got(target)
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if(endpoint.headers.link?.indexOf("webmention") >= 0) {
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// e.g. Link: <http://aaronpk.example/webmention-endpoint>; rel="webmention"
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return endpoint.headers.link
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.split(";")[0]
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.replace("<" ,"")
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.replace(">", "")
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}
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const format = mf2(endpoint.body, {
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// this also complies with w3.org regulations: relative endpoint could be possible
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baseUrl: baseUrlOf(target)
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})
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return format.rels?.webmention?.[0]
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} catch(err) {
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console.warn(` -- whoops, failed to discover ${target}, why: ${err}`)
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return undefined
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}
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}
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module.exports = {
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discover
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}
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