fix: Rewrite to interpret multiaddr from right to left

package.json

@@ -148,4 +148,4 @@
   "devDependencies": {
     "aegir": "^38.1.7"
   }
-}
+}

src/index.ts

@@ -1,74 +1,203 @@
-import type { Multiaddr } from '@multiformats/multiaddr'
-import { multiaddr } from '@multiformats/multiaddr'
+import type { Multiaddr, StringTuple } from '@multiformats/multiaddr'
+import { multiaddr, protocols } from '@multiformats/multiaddr'
 
 export interface MultiaddrToUriOpts {
   assumeHttp?: boolean
 }
 
-interface Reducer { (str: string, content: string, i: number, parts: Part[], opts?: MultiaddrToUriOpts): string }
+interface Interpreter { (value: string, ma: StringTuple[]): string }
 
-const reduceValue: Reducer = (_, v) => v
-const tcpUri = (str: string, port: string, parts: Part[], opts?: MultiaddrToUriOpts): string => {
-  // return tcp when explicitly requested
-  if ((opts != null) && opts.assumeHttp === false) return `tcp://${str}:${port}`
-  // check if tcp is the last protocol in multiaddr
-  let protocol = 'tcp'
-  let explicitPort = `:${port}`
-  const last = parts[parts.length - 1]
-  if (last.protocol === 'tcp') {
-    // assume http and produce clean urls
-    protocol = port === '443' ? 'https' : 'http'
-    explicitPort = port === '443' || port === '80' ? '' : explicitPort
+function extractSNI (ma: StringTuple[]): string | null {
+  let sniProtoCode: number
+  try {
+    sniProtoCode = protocols('sni').code
+  } catch (e) {
+    // No SNI protocol in multiaddr
+    return null
   }
-  return `${protocol}://${str}${explicitPort}`
+  for (const [proto, value] of ma) {
+    if (proto === sniProtoCode && value !== undefined) {
+      return value
+    }
+  }
+  return null
 }
 
-const Reducers: Record<string, Reducer> = {
-  ip4: reduceValue,
-  ip6: (str, content, i, parts) => (
-    parts.length === 1 && parts[0].protocol === 'ip6'
-      ? content
-      : `[${content}]`
-  ),
-  tcp: (str, content, i, parts, opts) => (
-    parts.some(p => ['http', 'https', 'ws', 'wss'].includes(p.protocol))
-      ? `${str}:${content}`
-      : tcpUri(str, content, parts, opts)
-  ),
-  udp: (str, content) => `udp://${str}:${content}`,
-  dnsaddr: reduceValue,
-  dns4: reduceValue,
-  dns6: reduceValue,
-  ipfs: (str, content) => `${str}/ipfs/${content}`,
-  p2p: (str, content) => `${str}/p2p/${content}`,
-  http: str => `http://${str}`,
-  https: str => `https://${str}`,
-  ws: str => `ws://${str}`,
-  wss: str => `wss://${str}`,
-  'p2p-websocket-star': str => `${str}/p2p-websocket-star`,
-  'p2p-webrtc-star': str => `${str}/p2p-webrtc-star`,
-  'p2p-webrtc-direct': str => `${str}/p2p-webrtc-direct`
+function hasTLS (ma: StringTuple[]): boolean {
+  return ma.some(([proto, _]) => proto === protocols('tls').code)
 }
 
-interface Part {
-  protocol: string
-  content: string
+function interpretNext (headProtoCode: number, headProtoVal: string, restMa: StringTuple[]): string {
+  const interpreter = interpreters[protocols(headProtoCode).name]
+  if (interpreter === undefined) {
+    throw new Error(`Can't interpret protocol ${protocols(headProtoCode).name}`)
+  }
+  const restVal = interpreter(headProtoVal, restMa)
+  if (headProtoCode === protocols('ip6').code) {
+    return `[${restVal}]`
+  }
+  return restVal
+}
+
+const interpreters: Record<string, Interpreter> = {
+  ip4: (value: string, restMa: StringTuple[]) => value,
+  ip6: (value: string, restMa: StringTuple[]) => {
+    if (restMa.length === 0) {
+      return value
+    }
+    return `[${value}]`
+  },
+  tcp: (value: string, restMa: StringTuple[]) => {
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    return `tcp://${interpretNext(tailProto[0], tailProto[1] ?? '', restMa)}:${value}`
+  },
+  udp: (value: string, restMa: StringTuple[]) => {
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    return `udp://${interpretNext(tailProto[0], tailProto[1] ?? '', restMa)}:${value}`
+  },
+  dnsaddr: (value: string, restMa: StringTuple[]) => value,
+  dns4: (value: string, restMa: StringTuple[]) => value,
+  dns6: (value: string, restMa: StringTuple[]) => value,
+  ipfs: (value: string, restMa: StringTuple[]) => {
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    return `${interpretNext(tailProto[0], tailProto[1] ?? '', restMa)}/ipfs/${value}`
+  },
+  p2p: (value: string, restMa: StringTuple[]) => {
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    return `${interpretNext(tailProto[0], tailProto[1] ?? '', restMa)}/p2p/${value}`
+  },
+  http: (value: string, restMa: StringTuple[]) => {
+    const maHasTLS = hasTLS(restMa)
+    const sni = extractSNI(restMa)
+    if (maHasTLS && sni !== null) {
+      return `https://${sni}`
+    }
+    const protocol = maHasTLS ? 'https://' : 'http://'
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    let baseVal = interpretNext(tailProto[0], tailProto[1] ?? '', restMa)
+    // We are reinterpreting the base as http, so we need to remove the tcp:// if it's there
+    baseVal = baseVal.replace('tcp://', '')
+    return `${protocol}${baseVal}`
+  },
+  tls: (value: string, restMa: StringTuple[]) => {
+    // Noop, the parent context knows that it's tls. We don't need to do
+    // anything here
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    return interpretNext(tailProto[0], tailProto[1] ?? '', restMa)
+  },
+  sni: (value: string, restMa: StringTuple[]) => {
+    // Noop, the parent context uses the sni information, we don't need to do
+    // anything here
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    return interpretNext(tailProto[0], tailProto[1] ?? '', restMa)
+  },
+  https: (value: string, restMa: StringTuple[]) => {
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    let baseVal = interpretNext(tailProto[0], tailProto[1] ?? '', restMa)
+    // We are reinterpreting the base as http, so we need to remove the tcp:// if it's there
+    baseVal = baseVal.replace('tcp://', '')
+    return `https://${baseVal}`
+  },
+  ws: (value: string, restMa: StringTuple[]) => {
+    const maHasTLS = hasTLS(restMa)
+    const sni = extractSNI(restMa)
+    if (maHasTLS && sni !== null) {
+      return `wss://${sni}`
+    }
+    const protocol = maHasTLS ? 'wss://' : 'ws://'
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    let baseVal = interpretNext(tailProto[0], tailProto[1] ?? '', restMa)
+    // We are reinterpreting the base, so we need to remove the tcp:// if it's there
+    baseVal = baseVal.replace('tcp://', '')
+    return `${protocol}${baseVal}`
+  },
+  wss: (value: string, restMa: StringTuple[]) => {
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    let baseVal = interpretNext(tailProto[0], tailProto[1] ?? '', restMa)
+    // We are reinterpreting the base as http, so we need to remove the tcp:// if it's there
+    baseVal = baseVal.replace('tcp://', '')
+    return `wss://${baseVal}`
+  },
+  'p2p-websocket-star': (value: string, restMa: StringTuple[]) => {
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    return `${interpretNext(tailProto[0], tailProto[1] ?? '', restMa)}/p2p-websocket-star`
+  },
+  'p2p-webrtc-star': (value: string, restMa: StringTuple[]) => {
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    return `${interpretNext(tailProto[0], tailProto[1] ?? '', restMa)}/p2p-webrtc-star`
+  },
+  'p2p-webrtc-direct': (value: string, restMa: StringTuple[]) => {
+    const tailProto = restMa.pop()
+    if (tailProto === undefined) {
+      throw new Error('Unexpected end of multiaddr')
+    }
+    return `${interpretNext(tailProto[0], tailProto[1] ?? '', restMa)}/p2p-webrtc-direct`
+  }
 }
 
 export function multiaddrToUri (input: Multiaddr | string | Uint8Array, opts?: MultiaddrToUriOpts): string {
   const ma = multiaddr(input)
-  const parts = ma.toString().split('/').slice(1)
-  return ma
-    .tuples()
-    .map(tuple => ({
-      protocol: parts.shift() ?? '',
-      content: (tuple[1] != null) ? parts.shift() ?? '' : ''
-    }))
-    .reduce((str: string, part: Part, i: number, parts: Part[]) => {
-      const reduce = Reducers[part.protocol]
-      if (reduce == null) {
-        throw new Error(`Unsupported protocol ${part.protocol}`)
+  const parts = ma.stringTuples()
+  const head = parts.pop()
+  if (head === undefined) {
+    throw new Error('Unexpected end of multiaddr')
+  }
+
+  const protocol = protocols(head[0])
+  const interpreter = interpreters[protocol.name]
+
+  if (interpreter == null) {
+    throw new Error(`No interpreter found for ${protocol.name}`)
+  }
+
+  let uri = interpreter(head[1] ?? '', parts)
+  if (opts?.assumeHttp !== false && head[0] === protocols('tcp').code) {
+    // If rightmost proto is tcp, we assume http here
+    uri = uri.replace('tcp://', 'http://')
+    if (head[1] === '443' || head[1] === '80') {
+      if (head[1] === '443') {
+        uri = uri.replace('http://', 'https://')
       }
-      return reduce(str, part.content, i, parts, opts)
-    }, '')
+      // Drop the port
+      uri = uri.substring(0, uri.lastIndexOf(':'))
+    }
+  }
+
+  return uri
 }

test/test.spec.ts

@@ -11,6 +11,8 @@ describe('multiaddr-to-uri', () => {
       ['/ip6/fc00::/http', 'http://[fc00::]'],
       ['/ip4/0.0.7.6/tcp/1234/http', 'http://0.0.7.6:1234'],
       ['/ip4/0.0.7.6/tcp/1234/https', 'https://0.0.7.6:1234'],
+      ['/ip4/0.0.7.6/tcp/1234/tls/http', 'https://0.0.7.6:1234'],
+      ['/ip4/1.2.3.4/tcp/1234/tls/sni/ipfs.io/http', 'https://ipfs.io'],
       ['/ip4/0.0.7.6/udp/1234', 'udp://0.0.7.6:1234'],
       ['/ip6/::/udp/0', 'udp://[::]:0'],
       ['/dnsaddr/ipfs.io', 'ipfs.io'],
@@ -25,6 +27,8 @@ describe('multiaddr-to-uri', () => {
       ['/ip4/1.2.3.4/tcp/3456/ws', 'ws://1.2.3.4:3456'],
       ['/ip6/::/tcp/0/ws', 'ws://[::]:0'],
       ['/dnsaddr/ipfs.io/wss', 'wss://ipfs.io'],
+      ['/dnsaddr/ipfs.io/tls/ws', 'wss://ipfs.io'],
+      ['/ip4/1.2.3.4/tcp/1234/tls/sni/ipfs.io/ws', 'wss://ipfs.io'],
       ['/ip4/1.2.3.4/tcp/3456/wss', 'wss://1.2.3.4:3456'],
       ['/ip6/::/tcp/0/wss', 'wss://[::]:0'],
       [