fix(self-hosting): use instance contacts and live product name (#3333)

fluxer_api/src/api/infrastructure/ErrorI18nService.test.ts

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import {getConfig} from '@app/api/Config';
+import {ErrorI18nService} from '@app/api/infrastructure/ErrorI18nService';
+import {APIErrorCodes} from '@fluxer/constants/src/ApiErrorCodes';
+import {StripeError} from '@fluxer/errors/src/domains/payment/StripeError';
+import {afterEach, describe, expect, it} from 'vitest';
+
+describe('ErrorI18nService', () => {
+	const originalSelfHosted = getConfig().instance.selfHosted;
+	const service = new ErrorI18nService();
+
+	function renderStripeError(locale: string): string {
+		const error = new StripeError('Stripe checkout session missing url');
+		return service.getMessage(error.code, locale, error.messageVariables, error.message);
+	}
+
+	afterEach(() => {
+		getConfig().instance.selfHosted = originalSelfHosted;
+	});
+
+	it('tells a hosted user to contact support when payment processing fails', () => {
+		getConfig().instance.selfHosted = false;
+		expect(renderStripeError('en-US')).toBe(
+			'Payment processing encountered an error. Please try again or contact support.',
+		);
+	});
+
+	it('points a self-hosted user at the instance administrators when payment processing fails', () => {
+		getConfig().instance.selfHosted = true;
+		expect(renderStripeError('en-US')).toBe(
+			'Payment processing encountered an error. Please try again or contact the administrators of this instance.',
+		);
+		expect(renderStripeError('de')).toBe(
+			'Bei der Zahlungsabwicklung ist ein Fehler aufgetreten. Versuch es noch mal oder kontaktiere die Administratoren dieser Instanz.',
+		);
+	});
+
+	it('lets a variable passed by the error win over the instance default', () => {
+		getConfig().instance.selfHosted = true;
+		expect(service.getMessage(APIErrorCodes.STRIPE_ERROR, 'en-US', {supportEmail: '[email protected]'})).toBe(
+			'Payment processing encountered an error. Please try again or contact support.',
+		);
+	});
+
+	it('leaves messages without the variable unchanged', () => {
+		getConfig().instance.selfHosted = true;
+		expect(service.getMessage(APIErrorCodes.RATE_LIMITED, 'en-US')).toBe("You're being rate limited.");
+	});
+});

fluxer_api/src/api/infrastructure/ErrorI18nService.ts

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 
+import {resolveContactEmails} from '@app/api/instance/ContactEmails';
 import {ErrorCodeToI18nKey} from '@fluxer/errors/src/i18n/ErrorCodeMappings';
 import {getErrorMessageUnsafe} from '@fluxer/errors/src/i18n/ErrorI18n';
 
@@ -11,6 +12,7 @@ export class ErrorI18nService {
 		fallbackMessage?: string,
 	): string {
 		const i18nKey = ErrorCodeToI18nKey[code as keyof typeof ErrorCodeToI18nKey] ?? code;
-		return getErrorMessageUnsafe(i18nKey, locale, variables, fallbackMessage);
+		const instanceVariables = {supportEmail: resolveContactEmails().supportEmail, ...variables};
+		return getErrorMessageUnsafe(i18nKey, locale, instanceVariables, fallbackMessage);
 	}
 }