Adding optional tests to showcase that it currently only works with electrs servers

Author: ulrichard

Cargo.toml

@@ -43,3 +43,7 @@ debug-calls = []
 proxy = ["byteorder", "winapi", "libc"]
 use-rustls = ["webpki", "webpki-roots", "rustls"]
 use-openssl = ["openssl"]
+test_servers = ["default"]
+
+[dev-dependencies]
+rstest = "^0.11"

tests/test_electrum_servers.rs

@@ -0,0 +1,21 @@
+extern crate electrum_client;
+extern crate rstest;
+
+use electrum_client::{Client, ElectrumApi};
+use rstest::rstest;
+
+// picked some random servers from https://1209k.com/bitcoin-eye/ele.php
+#[cfg(feature = "test_servers")]
+#[rstest]
+#[case::electrs(["electrum.blockstream.info", "ax101.blockeng.ch", "ax102.blockeng.ch", "ulrichard.ch"])]
+#[case::electrumx(["electrumx-core.1209k.com", "skbxmit.coinjoined.com", "eai.coincited.net", "bitcoin.lu.ke"])]
+#[case::fulcrum(["poonode-bitcoin.duckdns.org", "btc.lastingcoin.net", "de.poiuty.com", "fullnode.titanconnect.ca"])]
+fn test_electrum_servers(#[case] servers: [&str; 4]) {
+    for srv in servers {
+        let url = "ssl://".to_string() + srv + ":50002";
+        let client = Client::new(&url).unwrap();
+        if let Err(err) = client.ping() {
+            panic!("electrum server error {} : {:?}", url, err);
+        }
+    }
+}