prioritize error messages

lib/server.js

@@ -587,12 +587,12 @@ WalletService.prototype.joinWallet = function(opts, cb) {
         return cb(new ClientError());
       }
 
-      if (wallet.copayers.length == wallet.n) return cb(Errors.WALLET_FULL);
-
       if (_.find(wallet.copayers, {
         xPubKey: opts.xPubKey
       })) return cb(Errors.COPAYER_IN_WALLET);
 
+      if (wallet.copayers.length == wallet.n) return cb(Errors.WALLET_FULL);
+
       self._addCopayerToWallet(wallet, opts, cb);
     });
   });

test/integration/server.js

@@ -940,8 +940,8 @@ describe('Wallet service', function() {
       server = new WalletService();
       var walletOpts = {
         name: 'my wallet',
-        m: 2,
-        n: 3,
+        m: 1,
+        n: 2,
         pubKey: TestData.keyPair.pub,
       };
       server.createWallet(walletOpts, function(err, wId) {
@@ -1054,6 +1054,23 @@ describe('Wallet service', function() {
       });
     });
 
+    it('should return copayer in wallet error before full wallet', function(done) {
+      helpers.createAndJoinWallet(1, 1, function(s, wallet) {
+        var copayerOpts = helpers.getSignedCopayerOpts({
+          walletId: wallet.id,
+          name: 'me',
+          xPubKey: TestData.copayers[0].xPubKey_44H_0H_0H,
+          requestPubKey: TestData.copayers[0].pubKey_1H_0,
+          supportBIP44AndP2PKH: true,
+        });
+        server.joinWallet(copayerOpts, function(err) {
+          should.exist(err);
+          err.code.should.equal('COPAYER_IN_WALLET');
+          done();
+        });
+      });
+    });
+
     it('should fail to re-join wallet', function(done) {
       var copayerOpts = helpers.getSignedCopayerOpts({
         walletId: walletId,