Connection url ends in trailing forward slash (#50)

This commit fixes a bug in relation to the usage of url::join(). If A url
passed to Connection does not end in a trailing forward slash, a new url
will be constructed from the passed url with a trailing forward slash. When
joining a Connection url with an API path, the leading forward slash of the
path is trimmed, so that the path is appended to the url rather than replacing
any existing path segments.

Fixes #48

Author: russcam

elasticsearch/src/http/transport.rs

@@ -175,8 +175,17 @@ pub struct Connection {
 }
 
 impl Connection {
-    /// Creates a new instance of a [Connection]
+    /// Creates a new instance of a [Connection].
+    ///
+    /// If the passed [url::Url] does not have a trailing forward slash, a new
+    /// url is constructed from the passed url, with a trailing slash.
     pub fn new(url: Url) -> Self {
+        let url = if !url.path().ends_with('/') {
+            Url::parse(format!("{}/", url.as_str()).as_ref()).unwrap()
+        } else {
+            url
+        };
+
         Self { url }
     }
 }
@@ -236,7 +245,7 @@ impl Transport {
         Q: Serialize + ?Sized,
     {
         let connection = self.conn_pool.next();
-        let url = connection.url.join(path)?;
+        let url = connection.url.join(path.trim_start_matches('/'))?;
         let reqwest_method = self.method(method);
         let mut request_builder = self.client.request(reqwest_method, url);
 
@@ -460,7 +469,7 @@ impl ConnectionPool for CloudConnectionPool {
 #[cfg(test)]
 pub mod tests {
     use crate::auth::Credentials;
-    use crate::http::transport::{CloudId, TransportBuilder, SingleNodeConnectionPool};
+    use crate::http::transport::{CloudId, Connection, TransportBuilder, SingleNodeConnectionPool};
     use url::Url;
 
     #[test]
@@ -524,4 +533,32 @@ pub mod tests {
         let result = CloudId::parse(&cloud_id);
         assert!(result.is_err());
     }
+
+    #[test]
+    fn connection_url_with_no_trailing_slash() {
+        let url = Url::parse("http://10.1.2.3/path_with_no_trailing_slash").unwrap();
+        let conn = Connection::new(url);
+        assert_eq!(conn.url.as_str(), "http://10.1.2.3/path_with_no_trailing_slash/");
+    }
+
+    #[test]
+    fn connection_url_with_trailing_slash() {
+        let url = Url::parse("http://10.1.2.3/path_with_trailing_slash/").unwrap();
+        let conn = Connection::new(url);
+        assert_eq!(conn.url.as_str(), "http://10.1.2.3/path_with_trailing_slash/");
+    }
+
+    #[test]
+    fn connection_url_with_no_path_and_no_trailing_slash() {
+        let url = Url::parse("http://10.1.2.3").unwrap();
+        let conn = Connection::new(url);
+        assert_eq!(conn.url.as_str(), "http://10.1.2.3/");
+    }
+
+    #[test]
+    fn connection_url_with_no_path_and_trailing_slash() {
+        let url = Url::parse("http://10.1.2.3/").unwrap();
+        let conn = Connection::new(url);
+        assert_eq!(conn.url.as_str(), "http://10.1.2.3/");
+    }
 }