add unittest for error.go in pkg/app

Signed-off-by: yxxhero <aiopsclub@163.com>

pkg/app/errors_test.go

@@ -0,0 +1,39 @@
+package app
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestNoMatchingHelmfileError tests the NoMatchingHelmfileError error
+func TestNoMatchingHelmfileError_Error(t *testing.T) {
+	tests := []struct {
+		selectors []string
+		env       string
+		expected  string
+	}{
+		{
+			selectors: []string{"a", "b"},
+			env:       "c",
+			expected:  "err: no releases found that matches specified selector(a, b) and environment(c), in any helmfile",
+		},
+		{
+			selectors: []string{"a", "b"},
+			expected:  "err: no releases found that matches specified selector(a, b) and environment(), in any helmfile",
+		},
+		{
+			env:      "c",
+			expected: "err: no releases found that matches specified selector() and environment(c), in any helmfile",
+		},
+	}
+
+	for _, test := range tests {
+		err := &NoMatchingHelmfileError{
+			selectors: test.selectors,
+			env:       test.env,
+		}
+
+		require.Equal(t, test.expected, err.Error())
+	}
+}