Add basic integration test

Author: jebberjeb

TODO

@@ -2,11 +2,11 @@ Versioning
 	re: https://github.com/neovim/neovim/pull/5535
 	re: https://github.com/neovim/neovim/pull/5386
 
-	[_] an we start writing tests for these things?
+	[X] an we start writing tests for these things?
 		[X] We'd have to start an nvim --embed, and maybe specify the NVIM_... ? 
 		[X] Then, we connect
 		[X] Test version validation
-		[_] Integration test
+		[X] Integration test
 			-insert some text in current buffer
 			-command split the a new buffer put some stuff in it
 			-command switch back to the original buffer
@@ -17,7 +17,7 @@ Versioning
 		the version of Neovim used.
 
 	Following the philosophy described above, we need
-		[_] Make the user specify required API level on `connect`
+		[X] Make the user specify required API level on `connect`
 
 		[_] Change the api to one function `exec`, pass the op as the first
 		arg, and then use varargs, or a collection of args.

test/neovim-client/nvim_test.clj

@@ -48,5 +48,17 @@
       (is (client.nvim/version-supported?
             (client.nvim/new* 1 in out false))))))
 
+(deftest change-buffer-text
+  (with-neovim
+    (let [{:keys [in out]} *neovim*
+          conn (client.nvim/new* 1 in out false)]
+      (let [b1 (client.nvim/vim-get-current-buffer conn)
+            _ (client.nvim/buffer-set-line conn b1 0 "foo")
+            _ (client.nvim/vim-command conn "new")
+            b2 (client.nvim/vim-get-current-buffer conn)
+            _ (client.nvim/buffer-set-line conn b2 0 "bar")]
+        (is (= "foo" (client.nvim/buffer-get-line conn b1 0)))
+        (is (= "bar") (client.nvim/buffer-get-line conn b2 0))))))
+
 #_(clojure.tools.namespace.repl/refresh)
 #_(clojure.test/run-tests 'neovim-client.nvim-test)