diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..dedb624
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,9 @@
+[submodule "test/libs/bats"]
+	path = test/libs/bats
+	url = https://github.com/sstephenson/bats
+[submodule "test/libs/bats-assert"]
+	path = test/libs/bats-assert
+	url = https://github.com/ztombol/bats-assert
+[submodule "test/libs/bats-support"]
+	path = test/libs/bats-support
+	url = https://github.com/ztombol/bats-support
diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..b589ccf
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,9 @@
+# travis does not offer python container for OSX or Windows, not sure if we can get automated testing?
+os: linux
+language: python
+python:
+  - "3.6"
+dist: bionic
+install:
+  - pip install -r requirements.txt
+script: ./test.sh
diff --git a/bashtop b/bashtop
index ee4c6fe..2f07e3c 100755
--- a/bashtop
+++ b/bashtop
@@ -4822,6 +4822,10 @@ else
 	exec 2>/dev/null
 fi
 
+
+#* if we have been sourced by another shell, quit. Allows sourcing only function definition.
+[[ "${#BASH_SOURCE[@]}" -gt 1 ]] && { return 0; }
+
 #* Call init function
 init_
 
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..24156d6
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1 @@
+psutil==5.7.0
diff --git a/test.sh b/test.sh
new file mode 100755
index 0000000..958110a
--- /dev/null
+++ b/test.sh
@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+./test/libs/bats/bin/bats test/*.bats
diff --git a/test/basic_test.bats b/test/basic_test.bats
new file mode 100644
index 0000000..e159b6f
--- /dev/null
+++ b/test/basic_test.bats
@@ -0,0 +1,17 @@
+#!/usr/bin/env bats
+
+load 'libs/bats-support/load'
+load 'libs/bats-assert/load'
+
+load test_helper
+
+@test "Sourcing works, by checking if \$system is set" {
+    run echo $system
+    refute_output ""
+}
+
+@test "#get_themes populates themes" {
+  get_themes
+  assert_success
+  assert [ ${#themes[@]} -gt 0 ]
+}
diff --git a/test/libs/bats b/test/libs/bats
new file mode 160000
index 0000000..0360811
--- /dev/null
+++ b/test/libs/bats
@@ -0,0 +1 @@
+Subproject commit 03608115df2071fff4eaaff1605768c275e5f81f
diff --git a/test/libs/bats-assert b/test/libs/bats-assert
new file mode 160000
index 0000000..9f88b42
--- /dev/null
+++ b/test/libs/bats-assert
@@ -0,0 +1 @@
+Subproject commit 9f88b4207da750093baabc4e3f41bf68f0dd3630
diff --git a/test/libs/bats-support b/test/libs/bats-support
new file mode 160000
index 0000000..004e707
--- /dev/null
+++ b/test/libs/bats-support
@@ -0,0 +1 @@
+Subproject commit 004e707638eedd62e0481e8cdc9223ad471f12ee
diff --git a/test/test_helper.bash b/test/test_helper.bash
new file mode 100644
index 0000000..d173159
--- /dev/null
+++ b/test/test_helper.bash
@@ -0,0 +1 @@
+source bashtop