Add stub_called function

test/stub_called-test.sh

@@ -0,0 +1,40 @@
+#! /usr/bin/env bash
+source "test-helper.sh"
+
+#
+# stub_called() tests.
+#
+
+# Returns 1 when stub doesn't exist.
+assert_raises 'stub_called "uname"' 1
+
+# Returns 1 when stub hasn't been called.
+stub "uname"
+assert_raises 'stub_called "uname"' 1
+restore "uname"
+
+# Returns 0 when stub has been called.
+stub "uname"
+uname
+assert_raises 'stub_called "uname"' 0
+restore "uname"
+
+# Returns 1 after called stub has been restored.
+stub "uname"
+uname
+restore "uname"
+assert_raises 'stub_called "uname"' 1
+
+# Restoring only resets called state of restored stub.
+stub "uname"
+stub "top"
+uname
+top
+restore "uname"
+assert_raises 'stub_called "uname"' 1
+assert_raises 'stub_called "top"' 0
+restore "top"
+
+
+# End of tests.
+assert_end "stub_called()"