Add deterministic block transaction drilldown

frontend/src/services/api/transactions.test.ts

@@ -2,6 +2,48 @@ import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 import { transactionsApi } from './transactions'
 
+describe('transactionsApi.listByBlockSafe', () => {
+  beforeEach(() => {
+    vi.restoreAllMocks()
+  })
+
+  it('returns normalized transactions for a specific block', async () => {
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: true,
+      json: async () => ({
+        items: [
+          {
+            hash: '0xabc',
+            block_number: 123,
+            block_hash: '0xdef',
+            transaction_index: 0,
+            from: { hash: '0x0000000000000000000000000000000000000001' },
+            to: { hash: '0x0000000000000000000000000000000000000002' },
+            value: '0',
+            gas_price: '1',
+            gas: '21000',
+            gas_used: '21000',
+            status: 'ok',
+            timestamp: '2026-04-16T09:40:12.000000Z',
+          },
+        ],
+      }),
+    })
+
+    vi.stubGlobal('fetch', fetchMock)
+
+    const result = await transactionsApi.listByBlockSafe(138, 123, 1, 10)
+
+    expect(result.ok).toBe(true)
+    expect(result.data).toHaveLength(1)
+    expect(result.data[0]?.hash).toBe('0xabc')
+    expect(fetchMock).toHaveBeenCalledTimes(1)
+    expect(fetchMock.mock.calls[0]?.[0]).toEqual(
+      expect.stringContaining('/api/v2/blocks/123/transactions?page=1&page_size=10'),
+    )
+  })
+})
+
 describe('transactionsApi.diagnoseMissing', () => {
   beforeEach(() => {
     vi.restoreAllMocks()