diff --git a/crew b/crew
index d37204d6b7..e9991fadcc 100755
--- a/crew
+++ b/crew
@@ -70,20 +70,6 @@ USER = `whoami`.chomp
 
 $LOAD_PATH.unshift "#{CREW_LIB_PATH}lib"
 
-# Parse arguments using docopt
-
-require 'docopt'
-begin
-  args = Docopt::docopt(DOC)
-rescue Docopt::Exit => e
-  puts e.message
-  exit 1
-end
-
-@opt_keep = args["--keep"]
-@opt_verbose = args["--verbose"]
-@opt_src = args["--build-from-source"]
-
 # colorization
 class String
   def colorize(color_code, shade)
@@ -155,9 +141,24 @@ class String
   end
 end
 
+return 0 if defined? CREW_INIT_ONLY
+
 #disallow sudo
 abort "Chromebrew should not be run as root.".lightred if Process.uid == 0
 
+# Parse arguments using docopt
+require 'docopt'
+begin
+  args = Docopt::docopt(DOC)
+rescue Docopt::Exit => e
+  puts e.message
+  exit 1
+end
+
+@opt_keep = args["--keep"]
+@opt_verbose = args["--verbose"]
+@opt_src = args["--build-from-source"]
+
 @device = JSON.parse(File.read(CREW_CONFIG_PATH + 'device.json'), symbolize_names: true)
 #symbolize also values
 @device.each do |key, elem|
@@ -203,9 +204,9 @@ end
 
 def regexp_search(pkgName)
   results = Dir["#{CREW_LIB_PATH}packages/*.rb"].sort \
-	  .select  { |f| File.basename(f, '.rb') =~ Regexp.new(pkgName, true) } \
-	  .collect { |f| File.basename(f, '.rb') } \
-	  .each    { |f| print_package(f, @opt_verbose) }
+    .select  { |f| File.basename(f, '.rb') =~ Regexp.new(pkgName, true) } \
+    .collect { |f| File.basename(f, '.rb') } \
+    .each    { |f| print_package(f, @opt_verbose) }
   if results.empty?
     Find.find ("#{CREW_LIB_PATH}packages/") do |packageName|
       if File.file? packageName
@@ -654,7 +655,7 @@ def install
     # perform post-install process
     post_install target_dir
   end
-	
+
   #add to installed packages
   @device[:installed_packages].push(name: @pkg.name, version: @pkg.version)
   File.open(CREW_CONFIG_PATH + 'device.json', 'w') do |file|
diff --git a/tests/README.md b/tests/README.md
new file mode 100644
index 0000000000..4fa0e6ffff
--- /dev/null
+++ b/tests/README.md
@@ -0,0 +1,7 @@
+## Creating tests
+
+To create a test, just create a `.rb` file. It should finish normally if the test passed, and end with `exit 1` otherwise, preferably explaining why the test failed.
+
+## Running tests
+
+Just run the `test_all` file. Running tests manually may not work!
diff --git a/tests/no_cycles.rb b/tests/no_cycles.rb
new file mode 100644
index 0000000000..1aaae0e334
--- /dev/null
+++ b/tests/no_cycles.rb
@@ -0,0 +1,50 @@
+require 'find'
+
+@all_pkgs = {}
+
+# Loads all packages
+Find.find("../packages") do |filename|
+  if File.extname(filename) == '.rb'
+    name = File.basename(filename, '.rb')
+    require("../packages/" + name)
+    pkg = Object.const_get(name.capitalize)
+    pkg.name = name
+    @all_pkgs[name] = pkg
+  end
+end
+
+# Looking for cycles. @path will keep the current dependency path.
+# @state will store :on_path for vertices on the current dependency path
+# and :visited for vertices that have already been checked not to lead to
+# cycles.
+@state = {}
+@path = []
+def dfs(pkg)
+  @path.push(pkg.name)
+  if @state[pkg] == :on_path
+    puts "Found dependency cycle!".lightred
+    while @path.first != @path.last
+      @path.shift
+    end
+    puts @path.to_s
+    exit 1
+  elsif @state[pkg] == nil
+    @state[pkg] = :on_path
+    if pkg.dependencies
+      pkg.dependencies.each do |name, v|
+        if name != pkg.name
+          dfs(@all_pkgs[name])
+        end
+      end
+    end
+    @state[pkg] = :visited
+  end
+  @path.pop
+end
+
+# Calls dfs for every path
+@all_pkgs.each do |name, pkg|
+  dfs(pkg)
+end
+
+puts "No dependency cycles found.".lightgreen
diff --git a/tests/test_all b/tests/test_all
new file mode 100755
index 0000000000..11028ac6bc
--- /dev/null
+++ b/tests/test_all
@@ -0,0 +1,15 @@
+#!/usr/bin/env ruby
+
+CREW_INIT_ONLY = true
+load '../crew'
+
+puts "Running tests..."
+
+Find.find(".") do |filename|
+  if File.extname(filename) == '.rb'
+    puts "\nTest Name: #{File.basename(filename, ".rb")}"
+    load filename
+  end
+end
+
+puts "\nAll tests successful.".lightgreen