Refactor paginated pages onto shared base, add property coverage

Extract PaginatedPage base for the recent feed and recent profiles page controllers to remove the duplicated load/canLoadMore pattern introduced with the 50-item page size. Refresh mutation manifests via the tool. Add property tests for the base pagination invariants (canLoadMore mirrors hasMore, load forwards limit/offset, item lookup). By refactorer.
2026-09-21 16:52:01 -07:00 · 2026-09-04 10:06:27 -07:00
parent 38f7a42b90
commit a9488d9ae2
4 changed files with 174 additions and 41 deletions
@@ -0,0 +1,112 @@
+/*
+  Property tests for the shared PaginatedPage base controller.
+
+  The unit tests probe a few fixed pagination shapes. These properties cover
+  the load/`canLoadMore`/lookup invariants over broad random inputs so they
+  hold everywhere for the recent feed and recent profiles pages:
+
+    - has more: canLoadMore always mirrors pagination.hasMore.
+    - forwarding: the load limit and offset forwarded to the memo-db client
+      match exactly what the caller requested.
+    - lookup: the item finder returns a loaded item by key and null otherwise.
+*/
+
+'use strict'
+
+const test = require('node:test')
+const { seededRandom, forAll, intGen } = require('./harness')
+const PaginatedPage = require('../../src/services/paginated-page')
+
+const rng = seededRandom(20260904)
+
+// A minimal concrete subclass exercising the shared base logic.
+class TestPage extends PaginatedPage {
+  constructor (deps = {}) {
+    super(deps, {
+      listField: 'items',
+      loadMethod: 'getItems',
+      errorMessage: 'Test page requires a memo db client.'
+    })
+  }
+
+  getItem (key) {
+    return this.items.find((item) => item.key === key) || null
+  }
+}
+
+function makeMemoDb (items, pagination) {
+  return {
+    async getItems ({ limit, offset }) {
+      return { items, pagination }
+    }
+  }
+}
+
+function fixtureGen () {
+  return () => {
+    const n = intGen(rng, 0, 8)()
+    const items = []
+    for (let i = 0; i < n; i++) {
+      items.push({ key: 'item-' + i, text: 'value ' + i })
+    }
+    return {
+      items,
+      pagination: { hasMore: rng() < 0.5 },
+      limit: intGen(rng, 1, 100)(),
+      offset: intGen(rng, 0, 200)()
+    }
+  }
+}
+
+test('canLoadMore always mirrors pagination.hasMore', async () => {
+  await forAll(
+    fixtureGen(),
+    async ({ items, pagination, limit, offset }) => {
+      const page = new TestPage({ memoDb: makeMemoDb(items, pagination) })
+      await page.load({ limit, offset })
+
+      return page.canLoadMore() === (pagination.hasMore === true) &&
+        page.pagination.hasMore === pagination.hasMore
+    },
+    { label: 'paginated canLoadMore mirrors hasMore' }
+  )
+})
+
+test('load forwards exactly the requested limit and offset to the memo-db client', async () => {
+  await forAll(
+    fixtureGen(),
+    async ({ items, pagination, limit, offset }) => {
+      const calls = []
+      const memoDb = {
+        async getItems (params) {
+          calls.push(params)
+          return { items, pagination }
+        }
+      }
+      const page = new TestPage({ memoDb })
+      await page.load({ limit, offset })
+
+      return calls.length === 1 &&
+        calls[0].limit === limit &&
+        calls[0].offset === offset
+    },
+    { label: 'paginated load forwards limit and offset' }
+  )
+})
+
+test('getItem returns a loaded item by key, otherwise null', async () => {
+  await forAll(
+    fixtureGen(),
+    async ({ items, pagination, limit, offset }) => {
+      const page = new TestPage({ memoDb: makeMemoDb(items, pagination) })
+      await page.load({ limit, offset })
+
+      if (items.length === 0) return true
+
+      const any = page.getItem(items[0].key)
+      if (!any || any.text !== items[0].text) return false
+      return page.getItem('does-not-exist') === null
+    },
+    { label: 'paginated getItem lookup' }
+  )
+})