Add testing using bats

.gitignore

@@ -0,0 +1,5 @@
+# OSX
+.DS_Store
+
+# Node
+node_modules

Dockerfile

@@ -0,0 +1,11 @@
+FROM node:alpine
+
+RUN apk add --no-cache bash
+
+RUN mkdir -p /app
+WORKDIR /app
+
+COPY . /app
+RUN npm install
+
+CMD ./node_modules/.bin/bats wait-for.bats

README.md

@@ -39,4 +39,11 @@ services:
     command: sh -c './wait-for db:5432 -- npm start'
     depends_on:
       - db
-```
+```
+
+## Testing
+
+Ironically testing is done using [bats](https://github.com/sstephenson/bats), which on the other hand is depending on [bash](https://en.wikipedia.org/wiki/Bash_(Unix_shell)).
+
+    docker build -t wait-for .
+    docker run -t wait-for

package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "bats": "^0.4.2"
+  }
+}

wait-for

@@ -22,7 +22,8 @@ USAGE
 wait_for() {
   command="$*"
   for i in `seq $TIMEOUT` ; do
-    nc -z "$HOST" "$PORT"
+    nc -z "$HOST" "$PORT" > /dev/null 2>&1
+    
     result=$?
     if [ $result -eq 0 ] ; then
       if [ -n "$command" ] ; then

wait-for.bats

@@ -0,0 +1,14 @@
+#!/usr/bin/env bats
+
+@test "google should be immediately found" {
+  run ./wait-for google.com:80 -- echo 'success'
+  
+  [ "$output" = "success" ]
+}
+
+@test "nonexistent server should not start command" {
+  run ./wait-for -t 1 noserver:9999 -- echo 'success'
+
+  [ "$status" -ne 0 ]
+  [ "$output" != "success" ]
+}