Expand Vitest coverage for shared frontend utils.

Cover Axios error message extraction, generic error fallbacks, ArrayBuffer views used by Web Crypto, and share URL builders.

frontend/src/utils/http/resolveAxiosErrorMessage.spec.ts

@@ -0,0 +1,82 @@
+import { AxiosError, type InternalAxiosRequestConfig } from 'axios';
+import { describe, expect, it } from 'vitest';
+import { resolveAxiosErrorMessage } from '@/utils/http/resolveAxiosErrorMessage';
+
+const fallback = 'Upload failed';
+
+const axiosErrorWithResponse = (data: unknown, message = 'Request failed'): AxiosError => {
+    return new AxiosError(
+        message,
+        AxiosError.ERR_BAD_REQUEST,
+        {} as InternalAxiosRequestConfig,
+        {},
+        {
+            status: 400,
+            statusText: 'Bad Request',
+            headers: {},
+            config: {} as InternalAxiosRequestConfig,
+            data
+        }
+    );
+};
+
+describe('resolveAxiosErrorMessage', () => {
+    it('falls back for non-Axios errors', () => {
+        expect(resolveAxiosErrorMessage(new Error('network'), fallback)).toBe('network');
+        expect(resolveAxiosErrorMessage('oops', fallback)).toBe(fallback);
+    });
+
+    it('falls back when Axios error has no response', () => {
+        const error = new AxiosError('timeout', AxiosError.ETIMEDOUT);
+
+        expect(resolveAxiosErrorMessage(error, fallback)).toBe('timeout');
+    });
+
+    it('uses string response data', () => {
+        const error = axiosErrorWithResponse('Rate limit exceeded');
+
+        expect(resolveAxiosErrorMessage(error, fallback)).toBe('Rate limit exceeded');
+    });
+
+    it('uses object message string (Nest-style)', () => {
+        const error = axiosErrorWithResponse({ message: 'Invalid ciphertext' });
+
+        expect(resolveAxiosErrorMessage(error, fallback)).toBe('Invalid ciphertext');
+    });
+
+    it('uses a single string from message array', () => {
+        const error = axiosErrorWithResponse({ message: ['iv must be valid base64'] });
+
+        expect(resolveAxiosErrorMessage(error, fallback)).toBe('iv must be valid base64');
+    });
+
+    it('joins multiple strings in message array', () => {
+        const error = axiosErrorWithResponse({
+            message: ['expiresAt must be a date', 'maxViews must be a number']
+        });
+
+        expect(resolveAxiosErrorMessage(error, fallback)).toBe(
+            'expiresAt must be a date, maxViews must be a number'
+        );
+    });
+
+    it('ignores non-string entries in message array', () => {
+        const error = axiosErrorWithResponse({
+            message: ['valid', 42, null, 'also valid']
+        });
+
+        expect(resolveAxiosErrorMessage(error, fallback)).toBe('valid, also valid');
+    });
+
+    it('falls back when response data has no usable message', () => {
+        const error = axiosErrorWithResponse({ message: [] }, 'HTTP 400');
+
+        expect(resolveAxiosErrorMessage(error, fallback)).toBe('HTTP 400');
+    });
+
+    it('falls back when response data is an object without message', () => {
+        const error = axiosErrorWithResponse({ statusCode: 400 }, 'HTTP 400');
+
+        expect(resolveAxiosErrorMessage(error, fallback)).toBe('HTTP 400');
+    });
+});