feat: assume HTTP when multiaddr ends with /tcp (#7)

This makes multiaddrs ending with `/tcp/8080` to default to HTTP unless
an explicit assumeHttp: false is passed.

We also skip default ports for HTTP and HTTPS in the URL.

Motivation:
https://github.com/ipfs/js-ipfs/pull/2358#issue-307463029

License: MIT
Signed-off-by: Marcin Rataj <lidel@lidel.org>

README.md

@@ -18,10 +18,19 @@ const toUri = require('multiaddr-to-uri')
 
 console.log(toUri('/dnsaddr/protocol.ai/https'))
 // -> https://protocol.ai
+
+console.log(toUri('/ip4/127.0.0.1/tcp/8080'))
+// -> http://127.0.0.1:8080
+
+console.log(toUri('/ip4/127.0.0.1/tcp/8080', { assumeHttp: false }))
+// -> tcp://127.0.0.1:8080
 ```
 
 Note:
 
+* When `/tcp` is the last (terminating) protocol HTTP is assumed by default (implicit `assumeHttp: true`)
+  * this means produced URIs will start with `http://` instead of `tcp://`
+  * passing `{ assumeHttp: false }` disables this behavior
 * Might be lossy - e.g. a DNSv6 multiaddr
 * Can throw if the passed multiaddr:
     * is not a valid multiaddr

index.js

@@ -1,5 +1,20 @@
 const Multiaddr = require('multiaddr')
+
 const reduceValue = (_, v) => v
+const tcpUri = (str, port, parts, opts) => {
+  // return tcp when explicitly requested
+  if (opts && opts.assumeHttp === false) return `tcp://${str}:${port}`
+  // check if tcp is the last protocol in multiaddr
+  let protocol = 'tcp'
+  let explicitPort = `:${port}`
+  const last = parts[parts.length - 1]
+  if (last.protocol === 'tcp') {
+    // assume http and produce clean urls
+    protocol = port === 443 ? 'https' : 'http'
+    explicitPort = port === 443 || port === 80 ? '' : explicitPort
+  }
+  return `${protocol}://${str}${explicitPort}`
+}
 
 const Reducers = {
   ip4: reduceValue,
@@ -8,10 +23,10 @@ const Reducers = {
       ? content
       : `[${content}]`
   ),
-  tcp: (str, content, i, parts) => (
+  tcp: (str, content, i, parts, opts) => (
     parts.some(p => ['http', 'https', 'ws', 'wss'].includes(p.protocol))
       ? `${str}:${content}`
-      : `tcp://${str}:${content}`
+      : tcpUri(str, content, parts, opts)
   ),
   udp: (str, content) => `udp://${str}:${content}`,
   dnsaddr: reduceValue,
@@ -28,7 +43,7 @@ const Reducers = {
   'p2p-webrtc-direct': str => `${str}/p2p-webrtc-direct`
 }
 
-module.exports = (multiaddr) => (
+module.exports = (multiaddr, opts) => (
   Multiaddr(multiaddr)
     .stringTuples()
     .map(tuple => ({
@@ -38,6 +53,6 @@ module.exports = (multiaddr) => (
     .reduce((str, part, i, parts) => {
       const reduce = Reducers[part.protocol]
       if (!reduce) throw new Error(`Unsupported protocol ${part.protocol}`)
-      return reduce(str, part.content, i, parts)
+      return reduce(str, part.content, i, parts, opts)
     }, '')
 )

test.js

@@ -7,19 +7,14 @@ test('should convert multiaddr to URI', (t) => {
     ['/ip4/127.0.0.1/http', 'http://127.0.0.1'],
     ['/ip6/fc00::', 'fc00::'],
     ['/ip6/fc00::/http', 'http://[fc00::]'],
-    ['/ip4/0.0.7.6/tcp/1234', 'tcp://0.0.7.6:1234'],
     ['/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'],
-    ['/ip6/::/tcp/0', 'tcp://[::]:0'],
     ['/ip4/0.0.7.6/udp/1234', 'udp://0.0.7.6:1234'],
     ['/ip6/::/udp/0', 'udp://[::]:0'],
     ['/dnsaddr/ipfs.io', 'ipfs.io'],
     ['/dns4/ipfs.io', 'ipfs.io'],
     ['/dns4/libp2p.io', 'libp2p.io'],
     ['/dns6/protocol.ai', 'protocol.ai'],
-    ['/dns4/protocol.ai/tcp/80', 'tcp://protocol.ai:80'],
-    ['/dns6/protocol.ai/tcp/80', 'tcp://protocol.ai:80'],
-    ['/dnsaddr/protocol.ai/tcp/80', 'tcp://protocol.ai:80'],
     ['/dnsaddr/protocol.ai/tcp/80/http', 'http://protocol.ai:80'],
     ['/dnsaddr/protocol.ai/tcp/80/https', 'https://protocol.ai:80'],
     ['/dnsaddr/ipfs.io/ws', 'ws://ipfs.io'],
@@ -83,6 +78,40 @@ test('should convert multiaddr to URI', (t) => {
   data.forEach(d => t.is(toUri(d[0]), d[1]))
 })
 
+test('should convert multiaddr to http(s):// URI when implicit { assumeHttp: true }', (t) => {
+  const data = [
+    ['/ip4/0.0.7.6/tcp/1234', 'http://0.0.7.6:1234'],
+    ['/ip6/::/tcp/0', 'http://[::]:0'],
+    ['/dns4/protocol.ai/tcp/80', 'http://protocol.ai'],
+    ['/dns6/protocol.ai/tcp/80', 'http://protocol.ai'],
+    ['/dns4/protocol.ai/tcp/8080', 'http://protocol.ai:8080'],
+    ['/dns6/protocol.ai/tcp/8080', 'http://protocol.ai:8080'],
+    ['/dns4/protocol.ai/tcp/443', 'https://protocol.ai'],
+    ['/dns6/protocol.ai/tcp/443', 'https://protocol.ai'],
+    ['/dnsaddr/protocol.ai/tcp/80', 'http://protocol.ai'],
+    ['/dnsaddr/protocol.ai/tcp/443', 'https://protocol.ai'],
+    ['/dnsaddr/protocol.ai/tcp/8080', 'http://protocol.ai:8080']
+  ]
+  data.forEach(d => t.is(toUri(d[0]), d[1]))
+})
+
+test('should convert multiaddr to tcp:// URI when explicit { assumeHttp: false }', (t) => {
+  const data = [
+    ['/ip4/0.0.7.6/tcp/1234', 'tcp://0.0.7.6:1234'],
+    ['/ip6/::/tcp/0', 'tcp://[::]:0'],
+    ['/dns4/protocol.ai/tcp/80', 'tcp://protocol.ai:80'],
+    ['/dns6/protocol.ai/tcp/80', 'tcp://protocol.ai:80'],
+    ['/dns4/protocol.ai/tcp/8080', 'tcp://protocol.ai:8080'],
+    ['/dns6/protocol.ai/tcp/8080', 'tcp://protocol.ai:8080'],
+    ['/dns4/protocol.ai/tcp/443', 'tcp://protocol.ai:443'],
+    ['/dns6/protocol.ai/tcp/443', 'tcp://protocol.ai:443'],
+    ['/dnsaddr/protocol.ai/tcp/80', 'tcp://protocol.ai:80'],
+    ['/dnsaddr/protocol.ai/tcp/443', 'tcp://protocol.ai:443'],
+    ['/dnsaddr/protocol.ai/tcp/8080', 'tcp://protocol.ai:8080']
+  ]
+  data.forEach(d => t.is(toUri(d[0], { assumeHttp: false }), d[1]))
+})
+
 test('should throw for unsupported protocol', (t) => {
   t.throws(() => toUri('/quic'))
 })