Give connection errors friendlier error messages

- Wrap connection in try catch block
- Add tests for expected exceptions
- Add docstring
- Update CHANGELOG

Fixes #41

CHANGELOG.md

@@ -10,7 +10,8 @@ All notable changes to this project will be documented in this file. This change
 
 ### Changed
 - Add new arity for the queries `table-drop`, and `table-list` which doesn't require a db. [#54](https://github.com/apa512/clj-rethinkdb/pull/54/files)
-- Add docstring to `rethinkdb.query` ns explaining DB priority [#54](https://github.com/apa512/clj-rethinkdb/pull/54/files)
+- Add docstring to `rethinkdb.query` ns explaining DB priority [#54](https://github.com/apa512/clj-rethinkdb/pull/54)
+- Exceptions thrown when connecting are more descriptive, and are now of type `clojure.lang.ExceptionInfo`. [#41](https://github.com/apa512/clj-rethinkdb/issues/41) [#56](https://github.com/apa512/clj-rethinkdb/pull/56)
 
 ### Fixed
 - Fix close method on Connection record [#50](https://github.com/apa512/clj-rethinkdb/pull/50)

src/rethinkdb/core.clj

@@ -57,23 +57,26 @@
            token 0
            auth-key ""
            db nil}}]
-  (let [socket (Socket. host port)
-        out (DataOutputStream. (.getOutputStream socket))
-        in  (DataInputStream. (.getInputStream socket))]
-    ;; Initialise the connection
-    (send-version out)
-    (send-auth-key out auth-key)
-    (send-protocol out)
-    (let [init-response (read-init-response in)]
-      (if-not (= init-response "SUCCESS")
-        (throw (Exception. init-response))))
-    ;; Once initialised, create the connection record
-    (connection
-      (merge
-        {:socket socket
-         :out out
-         :in in
-         :db db
-         :waiting #{}
-         :token token}
-        (make-connection-loops in out)))))
+  (try
+    (let [socket (Socket. host port)
+          out (DataOutputStream. (.getOutputStream socket))
+          in (DataInputStream. (.getInputStream socket))]
+      ;; Initialise the connection
+      (send-version out)
+      (send-auth-key out auth-key)
+      (send-protocol out)
+      (let [init-response (read-init-response in)]
+        (if-not (= init-response "SUCCESS")
+          (throw (ex-info init-response {:host host :port port :auth-key auth-key :db db}))))
+      ;; Once initialised, create the connection record
+      (connection
+        (merge
+          {:socket socket
+           :out out
+           :in in
+           :db db
+           :waiting #{}
+           :token token}
+          (make-connection-loops in out))))
+    (catch Exception e
+      (throw (ex-info "Error connecting to RethinkDB database" {:host host :port port :auth-key auth-key :db db} e)))))

test/rethinkdb/core_test.clj

@@ -296,7 +296,8 @@
 
 (deftest query-conn
   (is (do (r/connect)
-          true)))
+          true))
+  (is (thrown? clojure.lang.ExceptionInfo (r/connect :port 1))))
 
 (use-fixtures :each setup-each)
 (use-fixtures :once setup-once)