diff --git a/internal/filter/filter_test.go b/internal/filter/filter_test.go
new file mode 100644
index 000000000..aa7048edf
--- /dev/null
+++ b/internal/filter/filter_test.go
@@ -0,0 +1,140 @@
+package filter
+
+import (
+	"errors"
+	"github.com/stretchr/testify/assert"
+	"regexp"
+	"strings"
+	"testing"
+)
+
+const unknown string = "unknown"
+
+var evalError = errors.New("evaluation error")
+
+func TestFilter(t *testing.T) {
+	t.Parallel()
+
+	filterable := &filterableType{
+		key:   "domain",
+		value: "example.com",
+	}
+
+	t.Run("InvalidOperator", func(t *testing.T) {
+		chain, err := NewChain("unknown", nil)
+		assert.Nil(t, chain)
+		assert.EqualError(t, err, "invalid logical operator provided: \"unknown\"")
+
+		condition, err := NewCondition("column", "unknown", "value")
+		assert.Nil(t, condition)
+		assert.EqualError(t, err, "invalid comparison operator provided: \"unknown\"")
+	})
+
+	t.Run("EvaluationError", func(t *testing.T) {
+		t.Parallel()
+
+		testInvalidData := []struct {
+			Expression string
+		}{
+			{"domain=" + unknown},
+			{"domain!=" + unknown},
+			{"domain<" + unknown},
+			{"domain<=" + unknown},
+			{"domain>" + unknown},
+			{"domain>=" + unknown},
+			{"domain~" + unknown},
+			{"domain!~" + unknown},
+			{"!(domain!=" + unknown + ")"},
+			{"domain=" + unknown + "&domain<=test.example.com"},
+			{"domain<=" + unknown + "|domain<=test.example.com"},
+		}
+
+		for _, td := range testInvalidData {
+			f, err := Parse(td.Expression)
+			assert.NoError(t, err)
+
+			matched, err := f.Eval(filterable)
+			assert.EqualError(t, err, evalError.Error())
+			assert.Equal(t, matched, false, "unexpected filter result for %q", td.Expression)
+		}
+	})
+
+	t.Run("EvaluateFilter", func(t *testing.T) {
+		t.Parallel()
+
+		testdata := []struct {
+			Expression string
+			Expected   bool
+		}{
+			{"domain=example.com", true},
+			{"domain!=example.com", false},
+			{"domain=test.example.com", false},
+			{"name!=example.com", false},
+			{"domain", true},
+			{"name", false},
+			{"display_name", false},
+			{"!name", true},
+			{"domain~example*", true},
+			{"domain!~example*", false},
+			{"domain~example*&!domain", false},
+			{"domain>a", true},
+			{"domain<a", false},
+			{"domain>z", false},
+			{"domain<z", true},
+			{"domain>=example&domain<=test.example.com", true},
+			{"domain<=example|domain<=test.example.com", true},
+			{"domain<=example|domain>=test.example.com", false},
+		}
+
+		for _, td := range testdata {
+			f, err := Parse(td.Expression)
+			if assert.NoError(t, err, "parsing %q should not return an error", td.Expression) {
+				matched, err := f.Eval(filterable)
+				assert.NoError(t, err)
+				assert.Equal(t, td.Expected, matched, "unexpected filter result for %q", td.Expression)
+			}
+		}
+	})
+}
+
+type filterableType struct {
+	key   string
+	value string
+}
+
+func (f *filterableType) EvalEqual(_ string, value string) (bool, error) {
+	if value == unknown {
+		return false, evalError
+	}
+
+	return strings.EqualFold(f.value, value), nil
+}
+
+func (f *filterableType) EvalLess(_ string, value string) (bool, error) {
+	if value == unknown {
+		return false, evalError
+	}
+
+	return f.value < value, nil
+}
+
+func (f *filterableType) EvalLike(_ string, value string) (bool, error) {
+	if value == unknown {
+		return false, evalError
+	}
+
+	regex := regexp.MustCompile("^example.*$")
+	return regex.MatchString(f.value), nil
+}
+
+func (f *filterableType) EvalLessOrEqual(_ string, value string) (bool, error) {
+	if value == unknown {
+		return false, evalError
+	}
+
+	return f.value <= value, nil
+}
+
+func (f *filterableType) EvalExists(key string) bool {
+	return f.key == key
+}