diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..ef0693c
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,11 @@
+.PHONY: clean all
+
+.PHONY: default
+default: test
+
+.PHONY: test
+test:
+	docker-compose -f ./tests/docker-compose-private.yml up \
+		--abort-on-container-exit --exit-code-from plugin
+	docker-compose -f ./tests/docker-compose-public.yml up \
+		--abort-on-container-exit --exit-code-from plugin
diff --git a/Readme.md b/Readme.md
index f0f7795..98cf613 100644
--- a/Readme.md
+++ b/Readme.md
@@ -46,3 +46,12 @@ The following environment variables can be used for further cutomization:
 | ``PLUGIN_TIMEOUT``          | Defines a timeout (in seconds) to stop the upload after a certain time.                                  |
 | ``PLUGIN_ATTEMPTS``         | Defines how often a failed upload should be retried. Normally there is only one upload attempt.          |
 | ``PLUGIN_CUSTOM_ARGUMENTS`` | Additional arguments to be passed to `curl`.                                                             |
+
+
+## Development
+
+There are only two tests right now and they are configured using Docker Compose. To run them, just use
+
+    make test
+
+If someone wants to make this better (or add a Drone file) I'd gladly accept the patch.
diff --git a/push.sh b/push.sh
index 1fe127f..b800d2f 100755
--- a/push.sh
+++ b/push.sh
@@ -1,31 +1,31 @@
 #! /bin/sh
 
 # Use WEBDAV_USERNAME as default, if provided.
-if [ -z "$PLUGIN_USERNAME" ] && [ ! -z "$WEBDAV_USERNAME" ]; then
+if [ -z "$PLUGIN_USERNAME" ] && [ -n "$WEBDAV_USERNAME" ]; then
 
     PLUGIN_USERNAME="$WEBDAV_USERNAME"
 fi
 
 # Use WEBDAV_PASSWORD as default, if provided.
-if [ -z "$PLUGIN_PASSWORD" ] && [ ! -z "$WEBDAV_PASSWORD" ]; then
+if [ -z "$PLUGIN_PASSWORD" ] && [ -n "$WEBDAV_PASSWORD" ]; then
 
     PLUGIN_PASSWORD="$WEBDAV_PASSWORD"
 fi
 
 # If username and password are provided, add auth
-if [ ! -z "$PLUGIN_USERNAME" ] && [ ! -z "$PLUGIN_PASSWORD" ]; then
+if [ -n "$PLUGIN_USERNAME" ] && [ -n "$PLUGIN_PASSWORD" ]; then
 
-    AUTH="--user '${PLUGIN_USERNAME}':'${PLUGIN_PASSWORD}'"
+    AUTH="--user '${PLUGIN_USERNAME}:${PLUGIN_PASSWORD}'"
 fi
 
 # Use a proxy, if one is specified
-if [ ! -z "$PLUGIN_PROXY_URL" ]; then
+if [ -n "$PLUGIN_PROXY_URL" ]; then
 
     PLUGIN_PROXY_URL="--proxy '${PLUGIN_PROXY_URL}'"
 fi
 
 # If a timeout is specified, make use of it.
-if [ ! -z "$PLUGIN_TIMEOUT" ]; then
+if [ -n "$PLUGIN_TIMEOUT" ]; then
 
     PLUGIN_TIMEOUT="--max-time '${PLUGIN_TIMEOUT}'"
 fi
@@ -55,6 +55,7 @@ while [ "${PLUGIN_ATTEMPTS}" -gt 0 ]; do
 
     }
 
+    sleep 5
     PLUGIN_ATTEMPTS=$((PLUGIN_ATTEMPTS-1))
 
 done
diff --git a/tests/docker-compose-private.yml b/tests/docker-compose-private.yml
new file mode 100644
index 0000000..8a2c0d9
--- /dev/null
+++ b/tests/docker-compose-private.yml
@@ -0,0 +1,21 @@
+---
+version: '2.4'
+services:
+  webdav:
+    image: sashgorokhov/webdav
+    environment:
+      USERNAME: jdoe
+      PASSWORD: hunter2
+
+  plugin:
+    build:
+      context: ../
+      dockerfile: Dockerfile
+    volumes:
+      - './test.txt:/test.txt'
+    environment:
+      PLUGIN_FILE: '/test.txt'
+      PLUGIN_DESTINATION: 'http://webdav/'
+      PLUGIN_USERNAME: jdoe
+      PLUGIN_PASSWORD: hunter2
+      PLUGIN_ATTEMPTS: 4
diff --git a/tests/docker-compose-public.yml b/tests/docker-compose-public.yml
new file mode 100644
index 0000000..e364aba
--- /dev/null
+++ b/tests/docker-compose-public.yml
@@ -0,0 +1,16 @@
+---
+version: '2.4'
+services:
+  webdav:
+    image: sashgorokhov/webdav
+
+  plugin:
+    build:
+      context: ../
+      dockerfile: Dockerfile
+    volumes:
+      - './test.txt:/test.txt'
+    environment:
+      PLUGIN_FILE: '/test.txt'
+      PLUGIN_DESTINATION: 'http://webdav/'
+      PLUGIN_ATTEMPTS: 4
diff --git a/tests/test.txt b/tests/test.txt
new file mode 100644
index 0000000..75c620d
--- /dev/null
+++ b/tests/test.txt
@@ -0,0 +1 @@
+ohai