ROX-35667: configurable user config path via ROXIE_USER_CONFIG_PATH

internal/paths/paths.go

@@ -8,7 +8,16 @@ import (
 
 const appName = "roxie"
 
+const envUserConfigPath = "ROXIE_USER_CONFIG_PATH"
+
 func UserConfigPath() (string, error) {
+	if overwrittenPath := os.Getenv(envUserConfigPath); overwrittenPath != "" {
+		if _, err := os.ReadFile(overwrittenPath); err != nil {
+			return "", fmt.Errorf("config file %q specified in environment variable %s cannot be read: %w",
+				overwrittenPath, envUserConfigPath, err)
+		}
+		return overwrittenPath, nil
+	}
 	dir, err := configDir()
 	if err != nil {
 		return "", fmt.Errorf("retrieving user config path: %w", err)

internal/paths/paths_test.go

@@ -0,0 +1,59 @@
+package paths
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestUserConfigPath(t *testing.T) {
+	tests := []struct {
+		name     string
+		envValue string
+		setEnv   bool
+	}{
+		{
+			name:     "returns env var value when set",
+			envValue: "/custom/path/config.yaml",
+			setEnv:   true,
+		},
+		{
+			name:   "returns default path when env var is not set",
+			setEnv: false,
+		},
+		{
+			name:     "returns default path when env var is empty",
+			envValue: "",
+			setEnv:   true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.setEnv {
+				t.Setenv(envUserConfigPath, tt.envValue)
+			}
+
+			got, err := UserConfigPath()
+			require.NoError(t, err)
+
+			if tt.setEnv && tt.envValue != "" {
+				assert.Equal(t, tt.envValue, got)
+			} else {
+				assert.Contains(t, got, "roxie/config.yaml")
+			}
+		})
+	}
+}
+
+func TestUserConfigPathString(t *testing.T) {
+	t.Run("returns env var value when set", func(t *testing.T) {
+		t.Setenv(envUserConfigPath, "/custom/path/config.yaml")
+		assert.Equal(t, "/custom/path/config.yaml", UserConfigPathString())
+	})
+
+	t.Run("returns default path when env var is not set", func(t *testing.T) {
+		assert.Contains(t, UserConfigPathString(), "roxie/config.yaml")
+	})
+}