fix(pagination): endIndex is incorrect if there's only 1 page of data (#4058)

* fix(pagination): `endIndex` calc incorrect, closes #4057

* test(pagination): pagination info

CHANGELOG.en-US.md

@@ -45,6 +45,7 @@
 - Fix `n-popover` doesn't wrap line if word is too long.
 - Fix `n-date-picker` can't delete all input content in some cases, closes [#3922](https://github.com/tusen-ai/naive-ui/issues/3922).
 - Fix `n-input`'s `autosize` prop doesn't work properly if there are multiple spaces, closes [#4027](https://github.com/tusen-ai/naive-ui/issues/4027).
+- Fix `n-pagination`'s `endIndex` calc incorrect，closes [#4057](https://github.com/tusen-ai/naive-ui/issues/4057)
 
 ### i18n
 

CHANGELOG.zh-CN.md

@@ -44,6 +44,7 @@
 - 修复 `n-timeline-item` 在 `n-timeline` 设定 `horizontal` 之后，`line-type="dashed"` 不生效，关闭 [#4014](https://github.com/tusen-ai/naive-ui/issues/4014)
 - 修复 `n-popover` 在英文和数字过长时不断行
 - 修复 `n-input` 的属性 `autosize` 在输入包含多个空格的时候表现不正确，关闭 [#4027](https://github.com/tusen-ai/naive-ui/issues/4027)
+- 修复 `n-pagination` 的 `endIndex` 计算错误，关闭 [#4057](https://github.com/tusen-ai/naive-ui/issues/4057)
 
 ### i18n
 

src/pagination/src/Pagination.tsx

@@ -271,7 +271,7 @@ export default defineComponent({
       const endIndex = mergedPageRef.value * mergedPageSizeRef.value - 1
       const { itemCount } = props
       if (itemCount !== undefined) {
-        return endIndex > itemCount ? itemCount : endIndex
+        return endIndex > itemCount - 1 ? itemCount - 1 : endIndex
       }
       return endIndex
     })

src/pagination/tests/Pagination.spec.tsx

@@ -1,6 +1,6 @@
 import { h } from 'vue'
 import { mount } from '@vue/test-utils'
-import { NPagination, PaginationRenderLabel } from '../index'
+import { NPagination, PaginationRenderLabel, PaginationInfo } from '../index'
 
 describe('n-pagination', () => {
   it('should work with import on demand', () => {
@@ -33,6 +33,36 @@ describe('n-pagination', () => {
     })
     expect(wrapper.findAll('.n-pagination-item').length).toEqual(4)
   })
+  it('should work with corrent pagination info', async () => {
+    let paginationInfo: PaginationInfo | undefined
+    const wrapper = mount(NPagination, {
+      props: {
+        itemCount: 1,
+        pageSize: 10,
+        prefix: (info: PaginationInfo) => {
+          paginationInfo = info
+        }
+      }
+    })
+    expect(wrapper.findAll('.n-pagination-item').length).toEqual(3)
+    expect(paginationInfo?.itemCount).toBe(1)
+    expect(paginationInfo?.page).toBe(1)
+    expect(paginationInfo?.pageCount).toBe(1)
+    expect(paginationInfo?.pageSize).toBe(10)
+    expect(paginationInfo?.startIndex).toBe(0)
+    expect(paginationInfo?.endIndex).toBe(0)
+    await wrapper.setProps({
+      itemCount: 12,
+      pageSize: 5,
+      page: 3
+    })
+    expect(paginationInfo?.itemCount).toBe(12)
+    expect(paginationInfo?.pageSize).toBe(5)
+    expect(paginationInfo?.page).toBe(3)
+    expect(paginationInfo?.pageCount).toBe(3)
+    expect(paginationInfo?.startIndex).toBe(10)
+    expect(paginationInfo?.endIndex).toBe(11)
+  })
   it('should work with prev slot', async () => {
     const wrapper = mount(NPagination, {
       slots: {