fix: don't dial on relay if not enabled (libp2p#234)

Author: dryajov

src/dial.js

@@ -130,6 +130,10 @@ function dial (swarm) {
     function dialCircuit (cb) {
       log(`Falling back to dialing over circuit`)
       pi.multiaddrs.add(`/p2p-circuit/ipfs/${pi.id.toB58String()}`)
+      if (!swarm.transports[Circuit.tag]) {
+        return cb(new Error(`Circuit not enabled!`))
+      }
+
       swarm.transport.dial(Circuit.tag, pi, (err, conn) => {
         if (err) {
           log(err)

test/circuit.js

@@ -21,6 +21,7 @@ describe(`circuit`, function () {
   let peerA
   let swarmB // WS
   let peerB
+  let swarmC // no transports
   let peerC // just a peer
   let dialSpyA
 
@@ -39,6 +40,7 @@ describe(`circuit`, function () {
 
       swarmA = new Swarm(peerA, new PeerBook())
       swarmB = new Swarm(peerB, new PeerBook())
+      swarmC = new Swarm(peerC, new PeerBook())
 
       swarmA.transport.add('tcp', new TCP())
       swarmA.transport.add('WebSockets', new WS())
@@ -100,6 +102,16 @@ describe(`circuit`, function () {
     })
   })
 
+  it(`should not try circuit if not enabled`, function (done) {
+    swarmC.dial(peerA, (err, conn) => {
+      expect(err).to.exist()
+      expect(conn).to.not.exist()
+
+      expect(err).to.match(/Could not dial in any of the transports or relays/)
+      done()
+    })
+  })
+
   it(`should not dial circuit if other transport succeed`, function (done) {
     swarmA.dial(peerB, (err) => {
       expect(err).not.to.exist()