feat: add env-aware client log policy and const lint fixes

backend/internal/logger/client_log_policy_test.go

@@ -0,0 +1,79 @@
+package logger
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestClientDebugEnabled(t *testing.T) {
+	t.Run("non production enables debug by default", func(t *testing.T) {
+		assert.True(t, ClientDebugEnabled("dev", ""))
+		assert.True(t, ClientDebugEnabled("local", "false"))
+	})
+
+	t.Run("production disables debug by default", func(t *testing.T) {
+		assert.False(t, ClientDebugEnabled("production", ""))
+		assert.False(t, ClientDebugEnabled("prod", "false"))
+	})
+
+	t.Run("production accepts explicit debug override", func(t *testing.T) {
+		assert.True(t, ClientDebugEnabled("production", "true"))
+		assert.True(t, ClientDebugEnabled("production", "1"))
+		assert.True(t, ClientDebugEnabled("prod", "on"))
+	})
+}
+
+func TestShouldAcceptClientLog(t *testing.T) {
+	assert.False(t, ShouldAcceptClientLog("production", "", "INFO"))
+	assert.False(t, ShouldAcceptClientLog("production", "", "DEBUG"))
+	assert.True(t, ShouldAcceptClientLog("production", "", "WARN"))
+	assert.True(t, ShouldAcceptClientLog("production", "", "ERROR"))
+	assert.True(t, ShouldAcceptClientLog("production", "true", "INFO"))
+	assert.True(t, ShouldAcceptClientLog("dev", "", "INFO"))
+}
+
+func TestShouldFilterNoisyClientInfo(t *testing.T) {
+	assert.True(t, ShouldFilterNoisyClientInfo("production", "", "Navigating to /ko/signin"))
+	assert.False(t, ShouldFilterNoisyClientInfo("production", "true", "Navigating to /ko/signin"))
+	assert.False(t, ShouldFilterNoisyClientInfo("dev", "", "Navigating to /ko/signin"))
+}
+
+func TestSanitizeClientLogData(t *testing.T) {
+	input := map[string]interface{}{
+		"token": "raw-token",
+		"safe":  "ok",
+		"nested": map[string]interface{}{
+			"new_password": "secret-1",
+			"path":         "/ko/profile",
+		},
+		"arr": []interface{}{
+			map[string]interface{}{"authorization": "Bearer abc"},
+			"token=abc123",
+		},
+	}
+
+	result := SanitizeClientLogData(input)
+
+	assert.Equal(t, "*****", result["token"])
+	assert.Equal(t, "ok", result["safe"])
+
+	nested := result["nested"].(map[string]interface{})
+	assert.Equal(t, "*****", nested["new_password"])
+	assert.Equal(t, "/ko/profile", nested["path"])
+
+	arr := result["arr"].([]interface{})
+	first := arr[0].(map[string]interface{})
+	assert.Equal(t, "*****", first["authorization"])
+	assert.Equal(t, "token=*****", arr[1])
+}
+
+func TestSanitizeClientLogMessage(t *testing.T) {
+	msg := `FLUTTER_ERROR token=abc123 payload={"password":"hello","safe":"ok"} authorization:BearerX`
+	sanitized := SanitizeClientLogMessage(msg)
+	assert.NotContains(t, sanitized, "abc123")
+	assert.NotContains(t, sanitized, `"password":"hello"`)
+	assert.Contains(t, sanitized, `"password":"*****"`)
+	assert.Contains(t, sanitized, "token=*****")
+	assert.Contains(t, sanitized, "authorization=*****")
+}