Add pagination tests + fix pagination

jest.config.js

@@ -12,12 +12,14 @@ module.exports = {
       // jest-environment-jsdom 25 uses jsdom 15 which still supports node 10
       testEnvironment: 'jest-environment-jsdom',
       testPathIgnorePatterns: ['<rootDir>/tests/env', '<rootDir>/playgrounds'],
+      testMatch: ['**/*.tests.ts'],
     },
     {
       preset: 'ts-jest',
       displayName: 'node',
       testEnvironment: 'node',
       testPathIgnorePatterns: ['<rootDir>/tests/env', '<rootDir>/playgrounds'],
+      testMatch: ['**/*.tests.ts'],
     },
   ],
 }

src/client/index.ts

@@ -29,7 +29,7 @@ export function instantMeiliSearch(
           paginationTotalHits: paginationTotalHits || 200,
           primaryKey: primaryKey || undefined,
           placeholderSearch: placeholderSearch !== false, // true by default
-          hitsPerPage: hitsPerPage || 20, // 20 is the MeiliSearch's default limit value. `hitsPerPage` can be changed with `InsantSearch.configure`.
+          hitsPerPage: hitsPerPage === undefined ? 20 : hitsPerPage, // 20 is the MeiliSearch's default limit value. `hitsPerPage` can be changed with `InsantSearch.configure`.
           page: page || 0, // default page is 0 if none is provided
         }
 

src/transformers/__tests__/pagination.tests.ts

@@ -1,5 +1,172 @@
-describe('Working test', () => {
-  it('equal', () => {
-    expect(3).toBe(3)
-  })
-})
+import { getNumberPages, paginateHits } from '../'
+import { defaultContext } from './utils'
+
+const numberPagesTestParameters = [
+  {
+    hitsPerPage: 0,
+    hitsLength: 100,
+    numberPages: 0,
+  },
+  {
+    hitsPerPage: 1,
+    hitsLength: 100,
+    numberPages: 100,
+  },
+  {
+    hitsPerPage: 20,
+    hitsLength: 24,
+    numberPages: 2,
+  },
+  {
+    hitsPerPage: 20,
+    hitsLength: 0,
+    numberPages: 0,
+  },
+  {
+    hitsPerPage: 0,
+    hitsLength: 0,
+    numberPages: 0,
+  },
+  // Not an Algolia behavior. Algolia returns an error:
+  // "Value too small for \"hitsPerPage\" parameter, expected integer between 0 and 9223372036854775807",
+  {
+    hitsPerPage: -1,
+    hitsLength: 20,
+    numberPages: 0,
+  },
+  // Not an Algolia behavior. Algolia returns an error:
+  // "Value too small for \"hitsPerPage\" parameter, expected integer between 0 and 9223372036854775807",
+  {
+    hitsPerPage: 1.5,
+    hitsLength: 20,
+    numberPages: 14,
+  },
+]
+
+const paginateHitsTestsParameters = [
+  // Empty hits
+  {
+    hits: [],
+    page: 0,
+    hitsPerPage: 20,
+    returnedHits: [],
+  },
+  {
+    hits: [],
+    page: 100,
+    hitsPerPage: 0,
+    returnedHits: [],
+  },
+  {
+    hits: [],
+    page: 100,
+    hitsPerPage: 20,
+    returnedHits: [],
+  },
+
+  // Page 0
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 0,
+    hitsPerPage: 20,
+    returnedHits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+  },
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 0,
+    hitsPerPage: 0,
+    returnedHits: [],
+  },
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 0,
+    hitsPerPage: 20,
+    returnedHits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+  },
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 0,
+    hitsPerPage: 2,
+    returnedHits: [{ id: 1 }, { id: 2 }],
+  },
+
+  // Page 1
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 1,
+    hitsPerPage: 2,
+    returnedHits: [{ id: 3 }],
+  },
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 1,
+    hitsPerPage: 20,
+    returnedHits: [],
+  },
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 1,
+    hitsPerPage: 0,
+    returnedHits: [],
+  },
+
+  // Page 2
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 2,
+    hitsPerPage: 20,
+    returnedHits: [],
+  },
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 2,
+    hitsPerPage: 20,
+    returnedHits: [],
+  },
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 2,
+    hitsPerPage: 0,
+    returnedHits: [],
+  },
+  // Wrong types
+  // Not an Algolia behavior. Algolia returns an error:
+  // "Value too small for \"hitsPerPage\" parameter, expected integer between 0 and 9223372036854775807",
+  {
+    hits: [{ id: 1 }, { id: 2 }, { id: 3 }],
+    page: 0,
+    hitsPerPage: -1,
+    returnedHits: [],
+  },
+]
+
+describe.each(numberPagesTestParameters)(
+  'Get Number Pages tests',
+  ({ hitsPerPage, hitsLength, numberPages }) => {
+    it(`Should return ${numberPages} pages when hitsPerPage is ${hitsPerPage} and hits length is ${hitsLength}`, () => {
+      const response = getNumberPages(hitsLength, {
+        ...defaultContext,
+        hitsPerPage: hitsPerPage,
+      })
+      expect(response).toBe(numberPages)
+    })
+  }
+)
+
+describe.each(paginateHitsTestsParameters)(
+  'Paginate hits tests',
+  ({ hits, page, hitsPerPage, returnedHits }) => {
+    it(`Should return ${JSON.stringify(
+      returnedHits
+    )} when hitsPerPage is ${hitsPerPage}, number of page is ${page} and when hits is ${JSON.stringify(
+      hits
+    )}`, () => {
+      const response = paginateHits(hits, {
+        ...defaultContext,
+        page,
+        hitsPerPage,
+      })
+      expect(response).toEqual(returnedHits)
+    })
+  }
+)

src/transformers/__tests__/utils.ts

@@ -0,0 +1,13 @@
+import { MeiliSearch } from 'meilisearch'
+const HOST = 'http://localhost:7700'
+
+const defaultContext = {
+  client: new MeiliSearch({ host: HOST }),
+  paginationTotalHits: 200,
+  primaryKey: undefined,
+  placeholderSearch: true,
+  hitsPerPage: 20,
+  page: 0,
+}
+
+export { defaultContext }

src/transformers/pagination.ts

@@ -4,14 +4,17 @@ export const getNumberPages: GetNumberPages = function (
   hitsLength,
   { hitsPerPage }
 ) {
-  const adjust = hitsLength % hitsPerPage! === 0 ? 0 : 1
-  return Math.floor(hitsLength / hitsPerPage!) + adjust // total number of pages
+  if (hitsPerPage > 0) {
+    const NumberPages = Math.ceil(hitsLength / hitsPerPage) // total number of pages rounded up to the next largest integer.
+    return NumberPages
+  }
+  return 0
 }
 
 export const paginateHits: PaginateHits = function (
   hits,
   { page, hitsPerPage }
 ) {
-  const start = page * hitsPerPage!
+  const start = page * hitsPerPage
   return hits.splice(start, hitsPerPage)
 }