Merge pull request #15 from vadimkorr/feature/#14_Setup-jest-test

Feature/#14 setup jest test

.babelrc

@@ -0,0 +1,15 @@
+{
+  "presets": [
+    ["@babel/preset-env", {
+      "modules": false,
+      "targets": {
+        "browsers": "ie >= 11"
+      }
+    }]
+  ],
+  "env": {
+    "test": {
+      "presets": [["@babel/preset-env"]]
+    }
+  }
+}

package.json

@@ -28,10 +28,12 @@
     "build-storybook": "build-storybook",
     "build:docs": "set DOCS=true && rollup -c",
     "dev:docs": "set DOCS=true && rollup -c -w",
+    "test": "jest",
     "prepublishOnly": "npm run build"
   },
   "devDependencies": {
     "@babel/core": "^7.12.10",
+    "@babel/preset-env": "^7.12.11",
     "@rollup/plugin-commonjs": "^17.0.0",
     "@rollup/plugin-json": "^4.1.0",
     "@rollup/plugin-node-resolve": "^11.0.0",
@@ -40,9 +42,11 @@
     "@storybook/addon-links": "^6.1.14",
     "@storybook/svelte": "^6.1.14",
     "babel-loader": "^8.2.2",
+    "jest": "^26.6.3",
     "lodash": "^4.17.20",
     "mdsvex": "^0.8.9",
     "rollup": "^2.3.4",
+    "rollup-plugin-babel": "^4.4.0",
     "rollup-plugin-css-only": "^3.1.0",
     "rollup-plugin-livereload": "^2.0.0",
     "rollup-plugin-svelte": "^7.0.0",

rollup.config.js

@@ -5,6 +5,7 @@ import resolve from '@rollup/plugin-node-resolve';
 import json from '@rollup/plugin-json';
 import livereload from 'rollup-plugin-livereload';
 import { terser } from 'rollup-plugin-terser';
+import babel from 'rollup-plugin-babel';
 import css from 'rollup-plugin-css-only';
 import { mdsvex } from "mdsvex";
 
@@ -97,6 +98,10 @@ export default {
     production && terser(),
 
     json(),
+
+    babel({
+      exclude: 'node_modules/**',
+    })
   ],
   watch: {
     clearScreen: false

src/components/Carousel/Carousel.svelte

@@ -9,6 +9,7 @@
     addResizeEventListener,
     removeResizeEventListener
   } from '../../utils/event'
+  import { getAdjacentIndexes } from '../../utils/page'
 
   const directionFnDescription = {
     [NEXT]: showNextPage,
@@ -60,19 +61,14 @@
   let currentPageIndex = 0
   $: originalCurrentPageIndex = currentPageIndex - Number(infinite);
   let pagesCount = 0
-  $: originalPagesCount = Math.max(pagesCount - (infinite ? 2 : 0), 0) // without clones
+  $: originalPagesCount = Math.max(pagesCount - (infinite ? 2 : 0), 1) // without clones
   let pageWidth = 0
   let offset = 0
   let pageWindowElement
   let pagesElement
 
   // used for lazy loading images, preloaded only current, adjacent and cloanable images
-  $: loaded = [
+  $: loaded = getAdjacentIndexes(originalCurrentPageIndex, originalPagesCount)
-    ...new Set([
-      0, originalPagesCount-1,
-      originalCurrentPageIndex - 1, originalCurrentPageIndex, originalCurrentPageIndex + 1
-    ])
-  ].filter(index => index >= 0)
 
   function applyPageSizes() {
     const children = pagesElement.children

src/store.js

@@ -1,5 +1,9 @@
 import { writable } from 'svelte/store';
-import { getNextPageIndexFn, getPrevPageIndexFn } from './utils/page'
+import {
+  getNextPageIndexFn,
+  getPrevPageIndexFn,
+  getPageIndex
+} from './utils/page'
 
 const initState = {
   currentPageIndex: 0,
@@ -26,7 +30,7 @@ function createStore() {
     update(store => {
       return {
         ...store,
-        currentPageIndex: pageIndex < 0 ? 0 : Math.min(pageIndex, pagesCount - 1),
+        currentPageIndex: getPageIndex(pageIndex, pagesCount),
       }
     })
   }

src/utils/page.js

@@ -1,10 +1,12 @@
 export function getNextPageIndexLimited(currentPageIndex, pagesCount) {
-  return Math.min(currentPageIndex + 1, pagesCount - 1)
+  if (pagesCount < 1) throw new Error('pagesCount must be at least 1')
+  return Math.min(Math.max(currentPageIndex + 1, 0), pagesCount - 1)
 }
 
 export function getNextPageIndexInfinte(currentPageIndex, pagesCount) {
-  const newCurrentPageIndex = currentPageIndex + 1
+  if (pagesCount < 1) throw new Error('pagesCount must be at least 1')
-  return newCurrentPageIndex > pagesCount - 1 ? 0 : newCurrentPageIndex
+  const newCurrentPageIndex = Math.max(currentPageIndex, 0) + 1
+  return newCurrentPageIndex > pagesCount - 1 ? 0 : Math.max(newCurrentPageIndex, 0)
 }
 
 export function getNextPageIndexFn(infinite) {
@@ -12,14 +14,39 @@ export function getNextPageIndexFn(infinite) {
 }
 
 export function getPrevPageIndexLimited(currentPageIndex, pagesCount) {
-  return Math.max(currentPageIndex - 1, 0)
+  if (pagesCount < 1) throw new Error('pagesCount must be at least 1')
+  return Math.max(Math.min(currentPageIndex - 1, pagesCount - 1), 0)
 }
 
 export function getPrevPageIndexInfinte(currentPageIndex, pagesCount) {
-  const newCurrentPageIndex = currentPageIndex - 1
+  if (pagesCount < 1) throw new Error('pagesCount must be at least 1')
-  return newCurrentPageIndex >= 0 ? newCurrentPageIndex : pagesCount - 1
+  const newCurrentPageIndex = Math.min(currentPageIndex, pagesCount - 1) - 1
+  return newCurrentPageIndex >= 0 ? Math.min(newCurrentPageIndex, pagesCount - 1) : pagesCount - 1
 }
 
 export function getPrevPageIndexFn(infinite) {
   return infinite ? getPrevPageIndexInfinte : getPrevPageIndexLimited
 }
+
+export function getPageIndex(pageIndex, pagesCount) {
+  if (pagesCount < 1) throw new Error('pagesCount must be at least 1')
+  return pageIndex < 0 ? 0 : Math.min(pageIndex, pagesCount - 1)
+}
+
+export function getAdjacentIndexes(pageIndex, pagesCount, infinite) {
+  if (pagesCount < 1) throw new Error('pagesCount must be at least 1')
+  const _pageIndex = Math.max(0, Math.min(pageIndex, pagesCount - 1))
+  let rangeStart = _pageIndex - 1;
+  let rangeEnd = _pageIndex + 1;
+  rangeStart = rangeStart < 0
+    ? infinite
+      ? pagesCount - 1
+      : 0
+    : rangeStart 
+  rangeEnd = rangeEnd > pagesCount - 1
+    ? infinite
+        ? 0
+        : pagesCount - 1
+    : rangeEnd
+  return [...new Set([rangeStart, rangeEnd, _pageIndex])].sort((a, b) => a - b)
+}

src/utils/page.test.js

@@ -0,0 +1,155 @@
+import {
+  getNextPageIndexLimited,
+  getNextPageIndexInfinte,
+  getPrevPageIndexLimited,
+  getPrevPageIndexInfinte,
+  getPageIndex,
+  getAdjacentIndexes
+} from './page.js'
+
+describe('getNextPageIndexLimited', () => {
+  it('returns next page index as expected', () => {
+    const testCases = [
+      { currentPageIndex: -5, pagesCount: 3, expected: 0 },
+      { currentPageIndex: 0, pagesCount: 3, expected: 1 },
+      { currentPageIndex: 1, pagesCount: 3, expected: 2 },
+      { currentPageIndex: 2, pagesCount: 3, expected: 2 },
+      { currentPageIndex: 7, pagesCount: 3, expected: 2 },
+    ]
+    testCases.forEach(({ currentPageIndex, pagesCount, expected }) => {
+      expect(getNextPageIndexLimited(currentPageIndex, pagesCount)).toBe(expected)
+    })
+  })
+  it('throws error if pagesCount is less than 1', () => {
+    const currentPageIndex = 5
+    const pagesCount = 0
+    expect(
+      () => getNextPageIndexLimited(currentPageIndex, pagesCount)
+    ).toThrowError('pagesCount must be at least 1')
+  })
+})
+
+describe('getNextPageIndexInfinte', () => {
+  it('returns next page index as expected', () => {
+    const testCases = [
+      { currentPageIndex: -5, pagesCount: 3, expected: 1 },
+      { currentPageIndex: 0, pagesCount: 3, expected: 1 },
+      { currentPageIndex: 1, pagesCount: 3, expected: 2 },
+      { currentPageIndex: 2, pagesCount: 3, expected: 0 },
+      { currentPageIndex: 7, pagesCount: 3, expected: 0 },
+    ]
+    testCases.forEach(({ currentPageIndex, pagesCount, expected }) => {
+      expect(getNextPageIndexInfinte(currentPageIndex, pagesCount)).toBe(expected)
+    })
+  })
+  it('throws error if pagesCount is less than 1', () => {
+    const currentPageIndex = 5
+    const pagesCount = 0
+    expect(
+      () => getNextPageIndexInfinte(currentPageIndex, pagesCount)
+    ).toThrowError('pagesCount must be at least 1')
+  })
+})
+
+describe('getPrevPageIndexLimited', () => {
+  it('returns prev page index as expected', () => {
+    const testCases = [
+      { currentPageIndex: -5, pagesCount: 3, expected: 0 },
+      { currentPageIndex: 0, pagesCount: 3, expected: 0 },
+      { currentPageIndex: 1, pagesCount: 3, expected: 0 },
+      { currentPageIndex: 2, pagesCount: 3, expected: 1 },
+      { currentPageIndex: 7, pagesCount: 3, expected: 2 },
+    ]
+    testCases.forEach(({ currentPageIndex, pagesCount, expected }) => {
+      expect(getPrevPageIndexLimited(currentPageIndex, pagesCount)).toBe(expected)
+    })
+  })
+  it('throws error if pagesCount is less than 1', () => {
+    const currentPageIndex = 5
+    const pagesCount = 0
+    expect(
+      () => getPrevPageIndexLimited(currentPageIndex, pagesCount)
+    ).toThrowError('pagesCount must be at least 1')
+  })
+})
+
+describe('getPrevPageIndexInfinte', () => {
+  it('returns prev page index as expected', () => {
+    const testCases = [
+      { currentPageIndex: -5, pagesCount: 3, expected: 2 },
+      { currentPageIndex: 0, pagesCount: 3, expected: 2 },
+      { currentPageIndex: 1, pagesCount: 3, expected: 0 },
+      { currentPageIndex: 2, pagesCount: 3, expected: 1 },
+      { currentPageIndex: 7, pagesCount: 3, expected: 1 },
+    ]
+    testCases.forEach(({ currentPageIndex, pagesCount, expected }) => {
+      expect(getPrevPageIndexInfinte(currentPageIndex, pagesCount)).toBe(expected)
+    })
+  })
+  it('throws error if pagesCount is less than 1', () => {
+    const currentPageIndex = 5
+    const pagesCount = 0
+    expect(
+      () => getPrevPageIndexInfinte(currentPageIndex, pagesCount)
+    ).toThrowError('pagesCount must be at least 1')
+  })
+})
+
+describe('getPageIndex', () => {
+  it('returns normalized page index as expected', () => {
+    const testCases = [
+      { pageIndex: -5, pagesCount: 3, expected: 0 },
+      { pageIndex: 0, pagesCount: 3, expected: 0 },
+      { pageIndex: 1, pagesCount: 3, expected: 1 },
+      { pageIndex: 2, pagesCount: 3, expected: 2 },
+      { pageIndex: 7, pagesCount: 3, expected: 2 },
+    ]
+    testCases.forEach(({ pageIndex, pagesCount, expected }) => {
+      expect(getPageIndex(pageIndex, pagesCount)).toBe(expected)
+    })
+  })
+  it('throws error if pagesCount is less than 1', () => {
+    const pageIndex = 5
+    const pagesCount = 0
+    expect(
+      () => getPageIndex(pageIndex, pagesCount)
+    ).toThrowError('pagesCount must be at least 1')
+  })
+})
+
+describe('getAdjacentIndexes', () => {
+  it('returns indexes as expected if infinite', () => {
+    const testCases = [
+      { pageIndex: 0, pagesCount: 1, expected: [0] },
+      { pageIndex: -5, pagesCount: 10, expected: [0, 1, 9] },
+      { pageIndex: 0, pagesCount: 10, expected: [0, 1, 9] },
+      { pageIndex: 5, pagesCount: 10, expected: [4, 5, 6] },
+      { pageIndex: 9, pagesCount: 10, expected: [0, 8, 9] },
+      { pageIndex: 15, pagesCount: 10, expected: [0, 8, 9] },
+    ]
+    testCases.forEach(({ pageIndex, pagesCount, expected }) => {
+      expect(getAdjacentIndexes(pageIndex, pagesCount, true)).toEqual(expected)
+    })
+  })
+  it('returns indexes as expected if not infinite', () => {
+    const testCases = [
+      { pageIndex: 0, pagesCount: 1, expected: [0] },
+      { pageIndex: -5, pagesCount: 10, expected: [0, 1] },
+      { pageIndex: 0, pagesCount: 10, expected: [0, 1] },
+      { pageIndex: 5, pagesCount: 10, expected: [4, 5, 6] },
+      { pageIndex: 9, pagesCount: 10, expected: [8, 9] },
+      { pageIndex: 15, pagesCount: 10, expected: [8, 9] },
+    ]
+    testCases.forEach(({ pageIndex, pagesCount, expected }) => {
+      expect(getAdjacentIndexes(pageIndex, pagesCount, false)).toEqual(expected)
+    })
+  })
+  it('throws error if pagesCount is less than 1', () => {
+    const pageIndex = 5
+    const pagesCount = 0
+    const infinite = true
+    expect(
+      () => getAdjacentIndexes(pageIndex, pagesCount, infinite)
+    ).toThrowError('pagesCount must be at least 1')
+  })
+})