Add set_cookie test

tests/https-agent.rs

@@ -11,3 +11,30 @@ fn tls_connection_close() {
     assert_eq!(resp.status(), 404);
     resp.into_reader().read_to_end(&mut vec![]).unwrap();
 }
+
+#[cfg(feature = "tls")]
+#[cfg(feature = "cookies")]
+#[cfg(feature = "json")]
+#[test]
+fn agent_set_cookie() {
+    let agent = ureq::Agent::default().build();
+    let cookie = ureq::Cookie::build("name", "value")
+        .domain("httpbin.org")
+        .secure(true)
+        .finish();
+    agent.set_cookie(cookie);
+    let resp = agent
+        .get("https://httpbin.org/get")
+        .set("Connection", "close")
+        .call();
+    assert_eq!(resp.status(), 200);
+    assert_eq!(
+        "name=value",
+        resp.into_json()
+            .unwrap()
+            .get("headers")
+            .unwrap()
+            .get("Cookie")
+            .unwrap()
+    );
+}