Setup tests

.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/utils/page.js

@@ -1,10 +1,10 @@
 export function getNextPageIndexLimited(currentPageIndex, pagesCount) {
-  return Math.min(currentPageIndex + 1, pagesCount - 1)
+  return Math.min(Math.max(currentPageIndex + 1, 0), pagesCount - 1)
 }
 
 export function getNextPageIndexInfinte(currentPageIndex, pagesCount) {
-  const newCurrentPageIndex = currentPageIndex + 1
+  const newCurrentPageIndex = Math.max(currentPageIndex, 0) + 1
-  return newCurrentPageIndex > pagesCount - 1 ? 0 : newCurrentPageIndex
+  return newCurrentPageIndex > pagesCount - 1 ? 0 : Math.max(newCurrentPageIndex, 0)
 }
 
 export function getNextPageIndexFn(infinite) {
@@ -12,12 +12,12 @@ export function getNextPageIndexFn(infinite) {
 }
 
 export function getPrevPageIndexLimited(currentPageIndex, pagesCount) {
-  return Math.max(currentPageIndex - 1, 0)
+  return Math.max(Math.min(currentPageIndex - 1, pagesCount - 1), 0)
 }
 
 export function getPrevPageIndexInfinte(currentPageIndex, pagesCount) {
-  const newCurrentPageIndex = currentPageIndex - 1
+  const newCurrentPageIndex = Math.min(currentPageIndex, pagesCount - 1) - 1
-  return newCurrentPageIndex >= 0 ? newCurrentPageIndex : pagesCount - 1
+  return newCurrentPageIndex >= 0 ? Math.min(newCurrentPageIndex, pagesCount - 1) : pagesCount - 1
 }
 
 export function getPrevPageIndexFn(infinite) {