diff --git a/contribs/gmf/apps/desktop_alt/Controller.js b/contribs/gmf/apps/desktop_alt/Controller.js
index 4467b8891190..612491e8f58c 100644
--- a/contribs/gmf/apps/desktop_alt/Controller.js
+++ b/contribs/gmf/apps/desktop_alt/Controller.js
@@ -117,7 +117,7 @@ class Controller extends AbstractDesktopController {
     const fill = new Fill({color: [255, 255, 255, 0.6]});
     const stroke = new Stroke({color: [255, 0, 0, 1], width: 2});
     const image = new Circle({fill, radius, stroke});
-    const default_search_style = new Style({
+    const defaultSearchStyle = new Style({
       fill,
       image,
       stroke
@@ -128,7 +128,7 @@ class Controller extends AbstractDesktopController {
      * @export
      */
     this.searchStyles = {
-      'default': default_search_style
+      'default': defaultSearchStyle
     };
 
     // Allow angular-gettext-tools to collect the strings to translate
diff --git a/contribs/gmf/examples/objecteditinghub.js b/contribs/gmf/examples/objecteditinghub.js
index afe6db8e8281..b8d16b0abf38 100644
--- a/contribs/gmf/examples/objecteditinghub.js
+++ b/contribs/gmf/examples/objecteditinghub.js
@@ -424,7 +424,7 @@ MainController.appendParams = function(uri, params) {
   // remove any trailing ? or &
   uri = uri.replace(/[?&]$/, '');
   // append ? or & depending on whether uri has existing parameters
-  uri = uri.indexOf('?') === -1 ? `${uri}?` : `${uri}&`;
+  uri = uri.includes('?') ? `${uri}&` : `${uri}?`;
   return uri + qs;
 };
 
diff --git a/contribs/gmf/examples/xsdattributes.js b/contribs/gmf/examples/xsdattributes.js
index fe6b7d236648..32de5f8c1856 100644
--- a/contribs/gmf/examples/xsdattributes.js
+++ b/contribs/gmf/examples/xsdattributes.js
@@ -83,7 +83,7 @@ function MainController($timeout, gmfThemes, gmfXSDAttributes) {
     flatNodes.forEach((node) => {
       const groupNode = /** @type {import('gmf/themes.js').GmfGroup} */(node);
       // Get an array of all layers
-      if (groupNode.children === undefined && layerNames.indexOf(node.name) !== -1) {
+      if (groupNode.children === undefined && layerNames.includes(node.name)) {
         this.layers.push(/** @type {import('gmf/themes.js').GmfLayer} */(node));
       }
     });
diff --git a/contribs/gmf/src/authentication/Service.js b/contribs/gmf/src/authentication/Service.js
index e70aeee8f1fa..904c7a7e4473 100644
--- a/contribs/gmf/src/authentication/Service.js
+++ b/contribs/gmf/src/authentication/Service.js
@@ -189,7 +189,7 @@ export class AuthenticationService extends olEventsEventTarget {
    * @return {angular.IPromise<void>} Promise.
    */
   logout() {
-    const noReload = this.noReloadRole_ ? this.getRolesNames().indexOf(this.noReloadRole_) !== -1 : false;
+    const noReload = this.noReloadRole_ ? this.getRolesNames().includes(this.noReloadRole_) : false;
     const url = `${this.baseUrl_}/${RouteSuffix.LOGOUT}`;
     return this.$http_.get(url, {withCredentials: true}).then(() => {
       this.resetUser_(noReload);
diff --git a/contribs/gmf/src/controllers/AbstractMobileController.js b/contribs/gmf/src/controllers/AbstractMobileController.js
index f3d467dd39b8..6ba6d2e11ad7 100644
--- a/contribs/gmf/src/controllers/AbstractMobileController.js
+++ b/contribs/gmf/src/controllers/AbstractMobileController.js
@@ -182,6 +182,7 @@ export class AbstractMobileController extends AbstractAppController {
    */
   openNavMenu(target) {
     const navElements = document.getElementsByClassName('gmf-mobile-nav-button');
+    // eslint-disable-next-line @typescript-eslint/prefer-for-of
     for (let i = 0; i < navElements.length; i++) {
       const element = /** @type {HTMLElement} */(navElements[i]);
       if (element.dataset && element.dataset.target === target) {
diff --git a/contribs/gmf/src/controllers/bootstrap.js b/contribs/gmf/src/controllers/bootstrap.js
index daab64b7226d..ad536f660af5 100644
--- a/contribs/gmf/src/controllers/bootstrap.js
+++ b/contribs/gmf/src/controllers/bootstrap.js
@@ -12,7 +12,7 @@ import angular from 'angular';
 function bootstrap(module) {
   // Hack to make the bootstrap type check working with polyfill.io
   const oldObjectToString = Object.prototype.toString;
-  if (oldObjectToString.toString().indexOf('[native code]') < 0) {
+  if (!oldObjectToString.toString().includes('[native code]')) {
     Object.prototype.toString = function() {
       if (this === null) {
         return '[object Null]';
diff --git a/contribs/gmf/src/datasource/Manager.js b/contribs/gmf/src/datasource/Manager.js
index 1724006f4a86..2d2e7a06b347 100644
--- a/contribs/gmf/src/datasource/Manager.js
+++ b/contribs/gmf/src/datasource/Manager.js
@@ -1,5 +1,5 @@
 import angular from 'angular';
-import gmfDatasourceOGC from 'gmf/datasource/OGC.js';
+import GmfDatasourceOGC from 'gmf/datasource/OGC.js';
 import gmfDatasourceWFSAliases from 'gmf/datasource/WFSAliases.js';
 import gmfLayertreeSyncLayertreeMap, {getLayer} from 'gmf/layertree/SyncLayertreeMap.js';
 import gmfLayertreeTreeManager from 'gmf/layertree/TreeManager.js';
@@ -21,6 +21,7 @@ import {clear as clearObject} from 'ol/obj.js';
 import olLayerImage from 'ol/layer/Image.js';
 import olSourceImageWMS from 'ol/source/ImageWMS.js';
 import olSourceTileWMS from 'ol/source/TileWMS.js';
+import BaseLayer from 'ol/layer/Base.js';
 
 
 /**
@@ -254,7 +255,13 @@ export class DatasourceManager {
   handleDimensionsChange_() {
 
     // Create a layer list to update each one only once
+    /**
+     * @type {BaseLayer[]}
+     */
     const layers = [];
+    /**
+     * @type {string[]}
+     */
     const layerIds = [];
 
     const dataSources = this.dataSources_.getArray();
@@ -267,7 +274,7 @@ export class DatasourceManager {
               return;
             }
             const id = olUtilGetUid(layer);
-            if (layerIds.indexOf(id) == -1) {
+            if (!layerIds.includes(id)) {
               layers.push(layer);
               layerIds.push(id);
             }
@@ -667,7 +674,7 @@ export class DatasourceManager {
       options.wmtsUrl = wmtsUrl;
     }
     // Create the data source and add it to the cache
-    this.dataSourcesCache_[id] = new gmfDatasourceOGC(options);
+    this.dataSourcesCache_[id] = new GmfDatasourceOGC(options);
   }
 
   /**
@@ -884,8 +891,8 @@ export class DatasourceManager {
         }
         const gmfLayerWMS = /** @type {import('gmf/themes.js').GmfLayerWMS} */(dataSource.gmfLayer);
         if (olUtilGetUid(dsLayer) == olUtilGetUid(layer) &&
-            layer.get('querySourceIds').indexOf(String(dataSource.id)) >= 0 &&
-            gmfLayerWMS.layers.split(',').indexOf(wmsLayerName) >= 0) {
+            layer.get('querySourceIds').includes(String(dataSource.id)) &&
+            gmfLayerWMS.layers.split(',').includes(wmsLayerName)) {
 
           const id = olUtilGetUid(dataSource.gmfLayer);
           const item = this.treeCtrlCache_[id];
diff --git a/contribs/gmf/src/datasource/OGC.js b/contribs/gmf/src/datasource/OGC.js
index 806f8946f0d2..3cc408fce4c0 100644
--- a/contribs/gmf/src/datasource/OGC.js
+++ b/contribs/gmf/src/datasource/OGC.js
@@ -80,7 +80,7 @@ import ngeoDatasourceOGC from 'ngeo/datasource/OGC.js';
  * @private
  * @hidden
  */
-class gmfDatasourceOGC extends ngeoDatasourceOGC {
+class GmfDatasourceOGC extends ngeoDatasourceOGC {
 
   /**
    * A `gmf.datasource.OGC` extends a `ngeo.datasource.OGC` and
@@ -113,4 +113,4 @@ class gmfDatasourceOGC extends ngeoDatasourceOGC {
 
 }
 
-export default gmfDatasourceOGC;
+export default GmfDatasourceOGC;
diff --git a/contribs/gmf/src/disclaimer/component.js b/contribs/gmf/src/disclaimer/component.js
index bfd1ad907eef..955189c6a421 100644
--- a/contribs/gmf/src/disclaimer/component.js
+++ b/contribs/gmf/src/disclaimer/component.js
@@ -298,7 +298,7 @@ DisclaimerController.prototype.$onDestroy = function() {
 DisclaimerController.prototype.showDisclaimerMessage_ = function(msg) {
   msg = this.gettextCatalog_.getString(msg);
   if (this.external) {
-    if (this.msgs_.indexOf(msg) < 0) {
+    if (!this.msgs_.includes(msg)) {
       this.msgs_.push(msg);
     }
     this.msg = `${this.sce_.trustAsHtml(this.msgs_.join('<br />'))}`;
diff --git a/contribs/gmf/src/editing/editFeatureComponent.js b/contribs/gmf/src/editing/editFeatureComponent.js
index f1d0936a9c5f..0d46936402a8 100644
--- a/contribs/gmf/src/editing/editFeatureComponent.js
+++ b/contribs/gmf/src/editing/editFeatureComponent.js
@@ -710,8 +710,13 @@ Controller.prototype.save = function() {
     if (attribute.format) {
       if (this.feature.get(attribute.name)) {
         const name = this.feature.get(attribute.name);
-        console.assert(typeof name == 'string');
+        if (typeof name == 'string') {
+          throw new Error('Wrong name type');
+        }
         const value = dateFormatter.parseDate(name, attribute.format);
+        if (value === null) {
+          throw new Error('Missing date');
+        }
         let jsonFormat = 'Y-m-d\\TH:i:s';
         if (attribute.type === 'date') {
           jsonFormat = 'Y-m-d';
diff --git a/contribs/gmf/src/filters/filterselectorComponent.js b/contribs/gmf/src/filters/filterselectorComponent.js
index 084cb1704b6e..534e2e9bb738 100644
--- a/contribs/gmf/src/filters/filterselectorComponent.js
+++ b/contribs/gmf/src/filters/filterselectorComponent.js
@@ -6,7 +6,7 @@ import gmfDatasourceDataSourceBeingFiltered from 'gmf/datasource/DataSourceBeing
 
 import gmfDatasourceHelper from 'gmf/datasource/Helper.js';
 
-import gmfDatasourceOGC from 'gmf/datasource/OGC.js';
+import GmfDatasourceOGC from 'gmf/datasource/OGC.js';
 import gmfFiltersSavedFilters from 'gmf/filters/SavedFilters.js';
 
 import ngeoMessageModalComponent from 'ngeo/message/modalComponent.js';
@@ -410,7 +410,7 @@ class FilterSelectorController {
   handleDataSourcesAdd_(evt) {
     if (evt instanceof CollectionEvent) {
       const dataSource = evt.element;
-      if (dataSource instanceof gmfDatasourceOGC) {
+      if (dataSource instanceof GmfDatasourceOGC) {
         this.registerDataSource_(dataSource);
       }
     }
@@ -429,7 +429,7 @@ class FilterSelectorController {
   handleDataSourcesRemove_(evt) {
     if (evt instanceof CollectionEvent) {
       const dataSource = evt.element;
-      if (dataSource instanceof gmfDatasourceOGC) {
+      if (dataSource instanceof GmfDatasourceOGC) {
         this.unregisterDataSource_(dataSource);
       }
     }
diff --git a/contribs/gmf/src/lidarprofile/Manager.js b/contribs/gmf/src/lidarprofile/Manager.js
index d8ac60f682f7..d5896e8b5941 100644
--- a/contribs/gmf/src/lidarprofile/Manager.js
+++ b/contribs/gmf/src/lidarprofile/Manager.js
@@ -236,8 +236,8 @@ export class LidarprofileManager {
       const domain = this.plot.updateScaleX.domain();
       pytreeLinestring = '';
 
-      for (let i = 0; i < clippedLine.length; i++) {
-        pytreeLinestring += `{${clippedLine[i][0]},${clippedLine[i][1]}},`;
+      for (const clipped of clippedLine) {
+        pytreeLinestring += `{${clipped[0]},${clipped[1]}},`;
       }
       pytreeLinestring = pytreeLinestring.substr(0, pytreeLinestring.length - 1);
       maxLODWith = this.utils.getNiceLOD(domain[1] - domain[0], max_levels);
@@ -364,8 +364,8 @@ export class LidarprofileManager {
 
     const uInt8header = new Uint8Array(profile, 4, headerSize);
     let strHeaderLocal = '';
-    for (let i = 0; i < uInt8header.length; i++) {
-      strHeaderLocal += String.fromCharCode(uInt8header[i]);
+    for (const header of uInt8header) {
+      strHeaderLocal += String.fromCharCode(header);
     }
 
     try {
@@ -403,11 +403,14 @@ export class LidarprofileManager {
 
     const attr = jHeader.pointAttributes;
     const attributes = [];
-    for (let j = 0; j < attr.length; j++) {
-      if (this.config.serverConfig.point_attributes[attr[j]] != undefined) {
-        attributes.push(this.config.serverConfig.point_attributes[attr[j]]);
+    for (const att of attr) {
+      if (this.config.serverConfig.point_attributes[att] != undefined) {
+        attributes.push(this.config.serverConfig.point_attributes[att]);
       }
     }
+    /**
+     * @type {number}
+     */
     const scale = jHeader.scale;
 
     if (jHeader.points < 3) {
@@ -422,41 +425,52 @@ export class LidarprofileManager {
       const byteOffset = bytesPerPoint * i;
       const view = new DataView(buffer, byteOffset, bytesPerPoint);
       let aoffset = 0;
-      for (let k = 0; k < attributes.length; k++) {
-
-        if (attributes[k].value == 'POSITION_PROJECTED_PROFILE') {
+      for (const attribute of attributes) {
+        if (attribute.value == 'POSITION_PROJECTED_PROFILE') {
           const udist = view.getUint32(aoffset, true);
           const dist = udist * scale;
           points.distance.push(Math.round(100 * (distanceOffset + dist)) / 100);
           this.profilePoints.distance.push(Math.round(100 * (distanceOffset + dist)) / 100);
 
-        } else if (attributes[k].value == 'CLASSIFICATION') {
+        } else if (attribute.value == 'CLASSIFICATION') {
           const classif = view.getUint8(aoffset);
           points.classification.push(classif);
           this.profilePoints.classification.push(classif);
 
-        } else if (attributes[k].value == 'INTENSITY') {
+        } else if (attribute.value == 'INTENSITY') {
           const intensity = view.getUint8(aoffset);
           points.intensity.push(intensity);
           this.profilePoints.intensity.push(intensity);
 
-        } else if (attributes[k].value == 'COLOR_PACKED') {
+        } else if (attribute.value == 'COLOR_PACKED') {
           const r = view.getUint8(aoffset);
           const g = view.getUint8(aoffset + 1);
           const b = view.getUint8(aoffset + 2);
           points.color_packed.push([r, g, b]);
           this.profilePoints.color_packed.push([r, g, b]);
 
-        } else if (attributes[k].value == 'POSITION_CARTESIAN') {
-          const x = view.getInt32(aoffset, true) * scale + jHeader.boundingBox.lx;
-          const y = view.getInt32(aoffset + 4, true) * scale + jHeader.boundingBox.ly;
-          const z = view.getInt32(aoffset + 8, true) * scale + jHeader.boundingBox.lz;
+        } else if (attribute.value == 'POSITION_CARTESIAN') {
+          const lx = jHeader.boundingBox.lx;
+          if (typeof lx != 'number') {
+            throw new Error('Wrong lx type');
+          }
+          const ly = jHeader.boundingBox.ly;
+          if (typeof ly != 'number') {
+            throw new Error('Wrong ly type');
+          }
+          const lz = jHeader.boundingBox.lz;
+          if (typeof lz != 'number') {
+            throw new Error('Wrong lz type');
+          }
+          const x = view.getInt32(aoffset, true) * scale + lx;
+          const y = view.getInt32(aoffset + 4, true) * scale + ly;
+          const z = view.getInt32(aoffset + 8, true) * scale + lz;
           points.coords.push([x, y]);
           points.altitude.push(z);
           this.profilePoints.altitude.push(z);
           this.profilePoints.coords.push([x, y]);
         }
-        aoffset = aoffset + attributes[k].bytes;
+        aoffset = aoffset + attribute.bytes;
       }
     }
 
diff --git a/contribs/gmf/src/lidarprofile/Plot.js b/contribs/gmf/src/lidarprofile/Plot.js
index d3892328a289..547cc76a17c4 100644
--- a/contribs/gmf/src/lidarprofile/Plot.js
+++ b/contribs/gmf/src/lidarprofile/Plot.js
@@ -42,9 +42,9 @@ export default class {
 
     /**
      * d3.scaleLinear X scale.
-     * @type {Function}
+     * @type {function(number): number}
      */
-    this.updateScaleX = () => undefined;
+    this.updateScaleX = (x) => x;
 
     /**
      * d3.scaleLinear Y scale.
@@ -54,9 +54,9 @@ export default class {
 
     /**
      * d3.scaleLinear Y scale.
-     * @type {Function}
+     * @type {function(number): number}
      */
-    this.updateScaleY = () => undefined;
+    this.updateScaleY = (y) => y;
 
     /**
      * The material used for the drawing process. Initialized in the setup
@@ -309,11 +309,11 @@ export default class {
     const yAxis = d3axisLeft(this.scaleY)
       .tickSize(-this.width_);
 
-    const new_scaleX = tr.rescaleX(this.scaleX);
-    const new_scaleY = tr.rescaleY(this.scaleY);
+    const newScaleX = tr.rescaleX(this.scaleX);
+    const newScaleY = tr.rescaleY(this.scaleY);
 
-    svg.select('.x.axis').call(/** @type {any} */ (xAxis.scale(new_scaleX)));
-    svg.select('.y.axis').call(/** @type {any} */ (yAxis.scale(new_scaleY)));
+    svg.select('.x.axis').call(/** @type {any} */ (xAxis.scale(newScaleX)));
+    svg.select('.y.axis').call(/** @type {any} */ (yAxis.scale(newScaleY)));
 
     const canvas = d3select('#gmf-lidarprofile-container .lidar-canvas');
     const canvasEl = /** @type {HTMLCanvasElement} */(canvas.node());
@@ -327,8 +327,8 @@ export default class {
       .style('opacity', '0.5')
       .style('stroke', '#b7cff7');
 
-    this.updateScaleX = new_scaleX;
-    this.updateScaleY = new_scaleY;
+    this.updateScaleX = newScaleX;
+    this.updateScaleY = newScaleY;
 
   }
 
diff --git a/contribs/gmf/src/lidarprofile/Utils.js b/contribs/gmf/src/lidarprofile/Utils.js
index bfa64922cd51..1f801f31cfeb 100644
--- a/contribs/gmf/src/lidarprofile/Utils.js
+++ b/contribs/gmf/src/lidarprofile/Utils.js
@@ -350,9 +350,9 @@ export default class {
    */
   arrayMin(array) {
     let minVal = Infinity;
-    for (let i = 0; i < array.length; i++) {
-      if (array[i] < minVal) {
-        minVal = array[i];
+    for (const element of array) {
+      if (element < minVal) {
+        minVal = element;
       }
     }
     return minVal;
@@ -367,9 +367,9 @@ export default class {
   getPytreeLinestring(line) {
     const coords = line.getCoordinates();
     let pytreeLineString = '';
-    for (let i = 0; i < coords.length; i++) {
-      const px = coords[i][0];
-      const py = coords[i][1];
+    for (const coord of coords) {
+      const px = coord[0];
+      const py = coord[1];
       pytreeLineString += `{${Math.round(100 * px) / 100}, ${Math.round(100 * py) / 100}},`;
     }
     return pytreeLineString.substr(0, pytreeLineString.length - 1);
diff --git a/contribs/gmf/src/permalink/Permalink.js b/contribs/gmf/src/permalink/Permalink.js
index 05e8818d8614..be49b273d0bf 100644
--- a/contribs/gmf/src/permalink/Permalink.js
+++ b/contribs/gmf/src/permalink/Permalink.js
@@ -580,7 +580,7 @@ export function PermalinkService(
           }
         }
       );
-      newState[ParamPrefix.TREE_GROUP_LAYERS + firstParent.node.name] = gmfLayerNames.join(',');
+      newState[`${ParamPrefix.TREE_GROUP_LAYERS}${firstParent.node.name}`] = gmfLayerNames.join(',');
     }
     this.ngeoStateManager_.updateState(newState);
   });
@@ -588,9 +588,9 @@ export function PermalinkService(
     /** @type {Object<string, string>} */
     const newState = {};
     const opacity = treeCtrl.layer.getOpacity();
-    const stateName = (treeCtrl.parent.node.mixed ?
+    const stateName = `${(treeCtrl.parent.node.mixed ?
       ParamPrefix.TREE_OPACITY : ParamPrefix.TREE_GROUP_OPACITY
-    ) + treeCtrl.node.name;
+    )}${treeCtrl.node.name}`;
     newState[stateName] = opacity;
     this.ngeoStateManager_.updateState(newState);
   });
@@ -847,8 +847,7 @@ PermalinkService.prototype.getFeatures = function() {
 PermalinkService.prototype.setDimensions = function(dimensions) {
   // apply initial state
   const keys = this.ngeoLocation_.getParamKeysWithPrefix(ParamPrefix.DIMENSIONS);
-  for (let i = 0; i < keys.length; i++) {
-    const key = keys[i];
+  for (const key of keys) {
     const value = this.ngeoLocation_.getParam(key);
     if (!value) {
       throw new Error('Missing value');
@@ -1439,7 +1438,7 @@ PermalinkService.prototype.getWfsPermalinkData_ = function() {
     // filter groups are used, e.g. '?wfs_layer=osm_scale&wfs_ngroups=2&wfs_0_ele=380&
     // wfs_0_highway=bus_stop&&wfs_1_name=Grand-Pont'
     for (let i = 0; i < numGroups; i++) {
-      filterGroup = this.createFilterGroup_(`${ParamPrefix.WFS + i}_`, paramKeys);
+      filterGroup = this.createFilterGroup_(`${ParamPrefix.WFS}${i}_`, paramKeys);
       if (filterGroup !== null) {
         filterGroups.push(filterGroup);
       }
@@ -1476,7 +1475,7 @@ PermalinkService.prototype.createFilterGroup_ = function(prefix, paramKeys) {
 
   paramKeys.forEach((paramKey) => {
     if (paramKey == PermalinkParam.WFS_LAYER || paramKey == PermalinkParam.WFS_SHOW_FEATURES ||
-        paramKey == PermalinkParam.WFS_NGROUPS || paramKey.indexOf(prefix) != 0) {
+        paramKey == PermalinkParam.WFS_NGROUPS || !paramKey.startsWith(prefix)) {
       return;
     }
     const value = this.ngeoLocation_.getParam(paramKey);
diff --git a/contribs/gmf/src/print/component.js b/contribs/gmf/src/print/component.js
index 63c1ea4e2736..074a3f2eb3b6 100644
--- a/contribs/gmf/src/print/component.js
+++ b/contribs/gmf/src/print/component.js
@@ -778,7 +778,7 @@ export class PrintController {
 
     this.updateCustomFields_();
 
-    const hasLegend = this.layoutInfo.attributes.indexOf('legend') >= 0;
+    const hasLegend = this.layoutInfo.attributes.includes('legend');
     if (hasLegend) {
       this.fieldValues.legend = this.fieldValues.legend;
     } else {
@@ -997,7 +997,7 @@ export class PrintController {
     /** @type {Object<string, *>} */
     const customAttributes = {};
 
-    if (this.layoutInfo.attributes.indexOf('datasource') >= 0) {
+    if (this.layoutInfo.attributes.includes('datasource')) {
       customAttributes.datasource = datasource;
     }
 
diff --git a/contribs/gmf/src/profile/component.js b/contribs/gmf/src/profile/component.js
index c51a5ec77800..4e8560f0e011 100644
--- a/contribs/gmf/src/profile/component.js
+++ b/contribs/gmf/src/profile/component.js
@@ -546,10 +546,10 @@ ProfileController.prototype.getTooltipHTML_ = function() {
   innerHTML.push(`${this.profileLabels_.xAxis} ${separator} ${value}&nbsp;${this.currentPoint.xUnits}`);
   for (elevationName in this.currentPoint.elevations) {
     translatedElevationName = gettextCatalog.getString(elevationName);
-    const int_value = this.currentPoint.elevations[elevationName];
-    const value = int_value === null ?
+    const intValue = this.currentPoint.elevations[elevationName];
+    const value = intValue === null ?
       gettextCatalog.getString('no value') :
-      `${number(int_value, 0)}&nbsp;${this.currentPoint.yUnits}`;
+      `${number(intValue, 0)}&nbsp;${this.currentPoint.yUnits}`;
     innerHTML.push(`${translatedElevationName} ${separator} ${value}`);
   }
   return innerHTML.join('</br>');
diff --git a/contribs/gmf/src/query/gridComponent.js b/contribs/gmf/src/query/gridComponent.js
index 06bcc3af3252..6ed2e70c759a 100644
--- a/contribs/gmf/src/query/gridComponent.js
+++ b/contribs/gmf/src/query/gridComponent.js
@@ -615,7 +615,7 @@ QueryGridController.prototype.collectData_ = function(source) {
     if (properties !== undefined) {
       // Keeps distinct geometry names to remove theme later.
       featureGeometryName = feature.getGeometryName();
-      if (featureGeometriesNames.indexOf(featureGeometryName) === -1) {
+      if (!featureGeometriesNames.includes(featureGeometryName)) {
         featureGeometriesNames.push(featureGeometryName);
       }
 
@@ -678,7 +678,7 @@ QueryGridController.prototype.removeEmptyColumnsFn_ = function(allProperties) {
   allProperties.forEach((properties) => {
     keyToRemove = [];
     for (key in properties) {
-      if (keysToKeep.indexOf(key) === -1) {
+      if (!keysToKeep.includes(key)) {
         keyToRemove.push(key);
       }
     }
@@ -705,7 +705,7 @@ QueryGridController.prototype.makeGrid_ = function(data, source) {
       return false;
     }
   }
-  if (this.loadedGridSources.indexOf(sourceLabel) == -1) {
+  if (!this.loadedGridSources.includes(sourceLabel)) {
     this.loadedGridSources.push(sourceLabel);
   }
   this.gridSources[sourceLabel] = {
diff --git a/contribs/gmf/src/query/windowComponent.js b/contribs/gmf/src/query/windowComponent.js
index 39a1364cc3b5..415e7973bc60 100644
--- a/contribs/gmf/src/query/windowComponent.js
+++ b/contribs/gmf/src/query/windowComponent.js
@@ -442,8 +442,7 @@ QueryWindowController.prototype.next = function() {
 QueryWindowController.prototype.updateQueryResult_ = function(queryResult) {
   this.ngeoQueryResult.total = 0;
   this.ngeoQueryResult.sources.length = 0;
-  for (let i = 0; i < queryResult.sources.length; i++) {
-    const source = queryResult.sources[i];
+  for (const source of queryResult.sources) {
     source.features = source.features.filter((feature) => {
       console.assert(feature);
       return !isEmpty(getFilteredFeatureValues(feature));
@@ -518,15 +517,14 @@ QueryWindowController.prototype.animate_ = function(isNext) {
 QueryWindowController.prototype.collectFeatures_ = function() {
   const sources = this.ngeoQueryResult.sources;
   this.features_.clear();
-  for (let i = 0; i < sources.length; i++) {
-    const source = sources[i];
+  for (const source of sources) {
     if (this.selectedSource !== null && this.selectedSource !== source) {
       // when filtering on a source, only add features of the selected source
       continue;
     }
     const features = source.features;
-    for (let ii = 0; ii < features.length; ii++) {
-      this.features_.push(features[ii]);
+    for (const feature of features) {
+      this.features_.push(feature);
     }
   }
 };
diff --git a/contribs/gmf/src/raster/component.js b/contribs/gmf/src/raster/component.js
index 6bf25d89acc5..ae1f8e69b842 100644
--- a/contribs/gmf/src/raster/component.js
+++ b/contribs/gmf/src/raster/component.js
@@ -109,6 +109,7 @@ function rasterComponent() {
       'layer': '<gmfElevationLayer',
       'map': '=gmfElevationMap'
     },
+    // @ts-ignore
     link: (scope, element, attr) => {
       // @ts-ignore: scope...
       const ctrl = scope.ctrl;
@@ -234,6 +235,7 @@ Controller.prototype.toggleActive_ = function(active) {
      * @param {Event|import("ol/events/Event.js").default} event The event
      * @return {void}
      */
+    // @ts-ignore
     const listen = (event) => {
       this.scope_.$apply(() => {
         this.inViewport_ = true;
@@ -295,7 +297,11 @@ Controller.prototype.getRasterSuccess_ = function(resp) {
     const separator = postfix.length > 0 ?
       (options.hasOwnProperty('separator') ? options.separator : '\u00a0') : '';
     const args = Array.prototype.concat([value], custom_args);
-    this.elevation = this.filter_(filter)(...args) + separator + postfix;
+    const elevation = this.filter_(filter)(...args);
+    if (typeof elevation != 'string') {
+      throw new Error('Wrong elevation type');
+    }
+    this.elevation = elevation + separator + postfix;
   } else {
     const gettextCatalog = this.gettextCatalog;
     this.elevation = gettextCatalog.getString('No value');
diff --git a/contribs/gmf/src/search/component.js b/contribs/gmf/src/search/component.js
index 4e5be6a6bae8..7646e353f780 100644
--- a/contribs/gmf/src/search/component.js
+++ b/contribs/gmf/src/search/component.js
@@ -573,9 +573,7 @@ class SearchController {
       throw new Error('Missing map');
     }
     const gettextCatalog = this.gettextCatalog_;
-    for (let i = 0; i < this.datasources.length; i++) {
-      const datasource = this.datasources[i];
-
+    for (const datasource of this.datasources) {
       /** @type {string[]} */
       const groupValues = datasource.groupValues !== undefined ? datasource.groupValues : [];
       /** @type {gmfSearchAction[]} */
diff --git a/contribs/gmf/src/theme/Themes.js b/contribs/gmf/src/theme/Themes.js
index faf451d876e8..9aa418cb33c6 100644
--- a/contribs/gmf/src/theme/Themes.js
+++ b/contribs/gmf/src/theme/Themes.js
@@ -518,8 +518,8 @@ function getFlatInternalNodes(node, nodes) {
   const children = node.children;
   if (children !== undefined) {
     nodes.push(node);
-    for (let i = 0; i < children.length; i++) {
-      getFlatInternalNodes(children[i], nodes);
+    for (const child of children) {
+      getFlatInternalNodes(child, nodes);
     }
   }
 }
@@ -536,8 +536,8 @@ export function getFlatNodes(node, nodes) {
   // @ts-ignore: children only on GmfGroup
   const children = node.children;
   if (children !== undefined) {
-    for (let i = 0; i < children.length; i++) {
-      getFlatNodes(children[i], nodes);
+    for (const child of children) {
+      getFlatNodes(child, nodes);
     }
   } else {
     nodes.push(node);
diff --git a/examples/animation.js b/examples/animation.js
index de7cc2d2ec62..80b390602423 100644
--- a/examples/animation.js
+++ b/examples/animation.js
@@ -69,9 +69,8 @@ function MainController($timeout) {
   // But we need to do it asynchronously in order to have the `resizemap`
   // directive working. If we don't, the `ng-class` directive doesn't fire the
   // animation hooks.
-  const self = this;
   $timeout(() => {
-    self.open = true;
+    this.open = true;
   }, 0);
 }
 
diff --git a/examples/layerorder.js b/examples/layerorder.js
index d2dd0e7ff962..83ce940b0185 100644
--- a/examples/layerorder.js
+++ b/examples/layerorder.js
@@ -144,7 +144,7 @@ function MainController($scope) {
  */
 MainController.prototype.toggleRoadsLayer = function(val) {
   if (val === undefined) {
-    return this.map.getLayers().getArray().indexOf(this.roads_) >= 0;
+    return this.map.getLayers().getArray().includes(this.roads_);
   } else {
     if (val) {
       this.map.addLayer(this.roads_);
diff --git a/examples/mapfishprint.js b/examples/mapfishprint.js
index cf6eb20fe0a6..c9513ff6ca9d 100644
--- a/examples/mapfishprint.js
+++ b/examples/mapfishprint.js
@@ -237,9 +237,8 @@ MainController.prototype.handleGetStatusSuccess_ = function(ref, resp) {
     window.location.href = this.print_.getReportUrl(ref);
   } else {
     // The report is not ready yet. Check again in 1s.
-    const that = this;
     this.$timeout_(() => {
-      that.getStatus_(ref);
+      this.getStatus_(ref);
     }, 1000, false);
   }
 };
diff --git a/src/WFSDescribeFeatureType.js b/src/WFSDescribeFeatureType.js
index 92087c0adf60..43de34052e3c 100644
--- a/src/WFSDescribeFeatureType.js
+++ b/src/WFSDescribeFeatureType.js
@@ -102,9 +102,6 @@ const SEQUENCE_PARSERS_ = makeStructureNS(
  * @hidden
  */
 class WFSDescribeFeatureType extends olFormatXML {
-  constructor() {
-    super();
-  }
 }
 
 
diff --git a/src/download/Csv.js b/src/download/Csv.js
index d2f37a50473e..61aae38f661a 100644
--- a/src/download/Csv.js
+++ b/src/download/Csv.js
@@ -118,7 +118,7 @@ DownloadCsvService.prototype.getRow_ = function(values) {
     if (value !== undefined && value !== null) {
       value = `${value}`;
       // wrap each value into quotes and escape quotes with double quotes
-      return this.quote_ + value.replace(matchAllQuotesRegex, doubleQuote) + this.quote_;
+      return `${this.quote_}${value.replace(matchAllQuotesRegex, doubleQuote)}${this.quote_}`;
     } else {
       return '';
     }
diff --git a/src/format/FeatureHash.js b/src/format/FeatureHash.js
index 5355993b720e..67d8e4120a5e 100644
--- a/src/format/FeatureHash.js
+++ b/src/format/FeatureHash.js
@@ -273,7 +273,7 @@ class FeatureHash extends olFormatTextFeature {
   readFeatureFromText(text, opt_options) {
     console.assert(text.length > 2);
     console.assert(text[1] === '(');
-    console.assert(text[text.length - 1] === ')');
+    console.assert(text.endsWith(')'));
     let splitIndex = text.indexOf('~');
     const geometryText = splitIndex >= 0 ?
       `${text.substring(0, splitIndex)})` : text;
@@ -288,8 +288,8 @@ class FeatureHash extends olFormatTextFeature {
         attributesAndStylesText;
       if (attributesText != '') {
         const parts = attributesText.split('\'');
-        for (let i = 0; i < parts.length; ++i) {
-          const part = decodeURIComponent(parts[i]);
+        for (const encodedPart of parts) {
+          const part = decodeURIComponent(encodedPart);
           const keyVal = part.split('*');
           console.assert(keyVal.length === 2);
           let key = keyVal[0];
@@ -321,7 +321,7 @@ class FeatureHash extends olFormatTextFeature {
    * @override
    */
   readFeaturesFromText(text, opt_options) {
-    console.assert(text[0] === 'F');
+    console.assert(text.startsWith('F'));
     this.prevX_ = 0;
     this.prevY_ = 0;
     /** @type {Array<olFeature<import("ol/geom/Geometry.js").default>>} */
@@ -383,7 +383,7 @@ class FeatureHash extends olFormatTextFeature {
 
     if (encodedGeometry.length > 0) {
       // remove the final bracket
-      console.assert(encodedGeometry[encodedGeometry.length - 1] === ')');
+      console.assert(encodedGeometry.endsWith(')'));
       encodedGeometry = encodedGeometry.substring(0, encodedGeometry.length - 1);
       encodedParts.push(encodedGeometry);
     }
@@ -542,8 +542,7 @@ function encodeNumber_(num) {
 function encodeStyles_(styles, geometryType, encodedStyles) {
   const styleType = StyleTypes_[geometryType];
   console.assert(styleType !== undefined);
-  for (let i = 0; i < styles.length; ++i) {
-    const style = styles[i];
+  for (const style of styles) {
     const fillStyle = style.getFill();
     const imageStyle = style.getImage();
     const strokeStyle = style.getStroke();
@@ -715,8 +714,8 @@ function encodeStyleText_(textStyle, encodedStyles) {
  * @this {FeatureHash}
  */
 function readLineStringGeometry_(text) {
-  console.assert(text.substring(0, 2) === 'l(');
-  console.assert(text[text.length - 1] == ')');
+  console.assert(text.startsWith('l('));
+  console.assert(text.endsWith(')'));
   text = text.substring(2, text.length - 1);
   const flatCoordinates = this.decodeCoordinates_(text);
   return new olGeomLineString(flatCoordinates, olGeomGeometryLayout.XY);
@@ -732,8 +731,8 @@ function readLineStringGeometry_(text) {
  * @this {FeatureHash}
  */
 function readMultiLineStringGeometry_(text) {
-  console.assert(text.substring(0, 2) === 'L(');
-  console.assert(text[text.length - 1] == ')');
+  console.assert(text.startsWith('L('));
+  console.assert(text.endsWith(')'));
   text = text.substring(2, text.length - 1);
   /** @type {number[]} */
   let flatCoordinates = [];
@@ -756,8 +755,8 @@ function readMultiLineStringGeometry_(text) {
  * @this {FeatureHash}
  */
 function readPointGeometry_(text) {
-  console.assert(text.substring(0, 2) === 'p(');
-  console.assert(text[text.length - 1] == ')');
+  console.assert(text.startsWith('p('));
+  console.assert(text.endsWith(')'));
   text = text.substring(2, text.length - 1);
   const flatCoordinates = this.decodeCoordinates_(text);
   console.assert(flatCoordinates.length === 2);
@@ -774,8 +773,8 @@ function readPointGeometry_(text) {
  * @this {FeatureHash}
  */
 function readMultiPointGeometry_(text) {
-  console.assert(text.substring(0, 2) === 'P(');
-  console.assert(text[text.length - 1] == ')');
+  console.assert(text.startsWith('P('));
+  console.assert(text.endsWith(')'));
   text = text.substring(2, text.length - 1);
   const flatCoordinates = this.decodeCoordinates_(text);
   return new olGeomMultiPoint(flatCoordinates, olGeomGeometryLayout.XY);
@@ -791,8 +790,8 @@ function readMultiPointGeometry_(text) {
  * @this {FeatureHash}
  */
 function readPolygonGeometry_(text) {
-  console.assert(text.substring(0, 2) === 'a(');
-  console.assert(text[text.length - 1] == ')');
+  console.assert(text.startsWith('a('));
+  console.assert(text.endsWith(')'));
   text = text.substring(2, text.length - 1);
   /** @type {number[]} */
   let flatCoordinates = [];
@@ -823,8 +822,8 @@ function readPolygonGeometry_(text) {
  * @this {FeatureHash}
  */
 function readMultiPolygonGeometry_(text) {
-  console.assert(text.substring(0, 2) === 'A(');
-  console.assert(text[text.length - 1] == ')');
+  console.assert(text.startsWith('A('));
+  console.assert(text.endsWith(')'));
   text = text.substring(2, text.length - 1);
   /** @type {number[]} */
   let flatCoordinates = [];
@@ -974,7 +973,7 @@ function setStyleProperties_(text, feature) {
       throw new Error('Wrong fontSizeStr type');
     }
     let fontSize = parseFloat(fontSizeStr);
-    if (fontSizeStr.indexOf('px') !== -1) {
+    if (fontSizeStr.includes('px')) {
       fontSize = Math.round(fontSize / 1.333333);
     }
     properties.fontSize = fontSize;
@@ -1051,8 +1050,8 @@ function getStyleProperties_(text, feature) {
   /** @type {Object<string, boolean|number|string>} */
   const properties = {};
 
-  for (let i = 0; i < parts.length; ++i) {
-    const part = decodeURIComponent(parts[i]);
+  for (const encodedPart of parts) {
+    const part = decodeURIComponent(encodedPart);
     const keyVal = part.split('*');
     console.assert(keyVal.length === 2);
     const key = keyVal[0];
diff --git a/src/format/XSDAttribute.js b/src/format/XSDAttribute.js
index 63f9ddced5ef..6a562030b19f 100644
--- a/src/format/XSDAttribute.js
+++ b/src/format/XSDAttribute.js
@@ -25,10 +25,6 @@ export const FormatNumberType = {
  * @hidden
  */
 class XSDAttribute extends olFormatXML {
-  constructor() {
-    super();
-  }
-
   /**
    * @param {Document|Element|string} source Source.
    * @return {Array<import('ngeo/format/Attribute.js').Attribute>} The parsed result.
diff --git a/src/grid/component.js b/src/grid/component.js
index d42033831d42..3b5b4acd8799 100644
--- a/src/grid/component.js
+++ b/src/grid/component.js
@@ -256,8 +256,8 @@ GridController.prototype.selectRange_ = function(attributes) {
   // find the selected row which is the closest to the clicked row
   let distance = Infinity;
   let posClosestRow = posSelectedRows[0];
-  for (let j = 0; j < posSelectedRows.length; j++) {
-    const currentPos = posSelectedRows[j];
+  for (const posSelectedRow of posSelectedRows) {
+    const currentPos = posSelectedRow;
     const currentDistance = Math.abs(currentPos - posClickedRow);
     if (distance > currentDistance) {
       distance = currentDistance;
diff --git a/src/interaction/ModifyRectangle.js b/src/interaction/ModifyRectangle.js
index efc48b1a1cfc..24a5d1e82c86 100644
--- a/src/interaction/ModifyRectangle.js
+++ b/src/interaction/ModifyRectangle.js
@@ -263,9 +263,9 @@ class ModifyRectangle extends olInteractionPointer {
     const uid = olUtilGetUid(feature);
     const item = this.cache_[uid];
     const corners = item.corners;
-    for (let i = 0; i < corners.length; i++) {
+    for (const corner of corners) {
       /** @type {olSourceVector<import("ol/geom/Geometry.js").default>} */(this.vectorPoints_.getSource())
-        .removeFeature(corners[i]);
+        .removeFeature(corner);
     }
     this.feature_ = null;
     corners.length = 0;
diff --git a/src/layertree/Controller.js b/src/layertree/Controller.js
index 4817870db915..54985b8f13ea 100644
--- a/src/layertree/Controller.js
+++ b/src/layertree/Controller.js
@@ -327,7 +327,7 @@ LayertreeController.prototype.getSetActive = function(val) {
       map.addLayer(layer);
     }
   } else {
-    return map.getLayers().getArray().indexOf(layer) >= 0;
+    return map.getLayers().getArray().includes(layer);
   }
 };
 
@@ -397,8 +397,7 @@ LayertreeController.prototype.traverseDepthFirst = function(visitor) {
     case LayertreeVisitorDecision.SKIP:
       return false; // continue traversing but skip current branch
     case LayertreeVisitorDecision.DESCEND:
-      for (let i = 0; i < this.children.length; ++i) {
-        const child = this.children[i];
+      for (const child of this.children) {
         const stop = child.traverseDepthFirst(visitor);
         if (stop) {
           return true; // stop traversing
diff --git a/src/map/LayerHelper.js b/src/map/LayerHelper.js
index 87113615130a..d442debc3157 100644
--- a/src/map/LayerHelper.js
+++ b/src/map/LayerHelper.js
@@ -333,7 +333,7 @@ LayerHelper.prototype.getFlatLayers_ = function(layer, array, computedOpacity) {
       this.getFlatLayers_(l, array, computedOpacity);
     });
   } else if (layer instanceof olLayerLayer) {
-    if (array.indexOf(layer) < 0) {
+    if (!array.includes(layer)) {
       layer.set('inheritedOpacity', computedOpacity, true);
       array.push(layer);
     }
diff --git a/src/message/Message.js b/src/message/Message.js
index bb2716c4034f..c12925b75e3f 100644
--- a/src/message/Message.js
+++ b/src/message/Message.js
@@ -43,8 +43,6 @@ export const MessageType = {
  * @hidden
  */
 export default class {
-  constructor() {}
-
   /**
    * Show the message.
    *
diff --git a/src/misc/File.js b/src/misc/File.js
index 8f8d02dbaece..ea20d99cdf7c 100644
--- a/src/misc/File.js
+++ b/src/misc/File.js
@@ -29,21 +29,21 @@ export function FileService($q, $http, gettext) {
    * @param {string} fileContent
    */
   this.isWmtsGetCap = function(fileContent) {
-    return /<Capabilities/.test(fileContent);
+    return fileContent.includes('<Capabilities');
   };
 
   /**
    * @param {string} fileContent
    */
   this.isKml = function(fileContent) {
-    return /<kml/.test(fileContent) && /<\/kml>/.test(fileContent);
+    return fileContent.includes('<kml') && fileContent.includes('</kml>');
   };
 
   /**
    * @param {string} fileContent
    */
   this.isGpx = function(fileContent) {
-    return /<gpx/.test(fileContent) && /<\/gpx>/.test(fileContent);
+    return fileContent.includes('<gpx') && fileContent.includes('</gpx>');
   };
 
   /** @type {?FileReader} */
diff --git a/src/misc/ToolActivateMgr.js b/src/misc/ToolActivateMgr.js
index 684a9aa99856..774d17e30628 100644
--- a/src/misc/ToolActivateMgr.js
+++ b/src/misc/ToolActivateMgr.js
@@ -116,8 +116,8 @@ ToolActivateMgr.prototype.unregisterTool = function(groupName, tool) {
 ToolActivateMgr.prototype.unregisterGroup = function(groupName) {
   const entries = this.groups_[groupName];
   if (entries) {
-    for (let i = 0; i < entries.length; i++) {
-      entries[i].unlisten();
+    for (const entry of entries) {
+      entry.unlisten();
     }
     delete this.groups_[groupName];
   }
@@ -151,9 +151,9 @@ ToolActivateMgr.prototype.deactivateTool = function(tool) {
  */
 ToolActivateMgr.prototype.deactivateTools_ = function(groupName, tool) {
   const entries = this.groups_[groupName];
-  for (let i = 0; i < entries.length; i++) {
-    if (tool != entries[i].tool) {
-      entries[i].tool.setActive(false);
+  for (const entry of entries) {
+    if (tool != entry.tool) {
+      entry.tool.setActive(false);
     }
   }
 };
@@ -170,11 +170,11 @@ ToolActivateMgr.prototype.activateDefault_ = function(groupName) {
   let defaultTool = null;
   let hasActiveTool = false;
 
-  for (let i = 0; i < entries.length; i++) {
-    hasActiveTool = hasActiveTool || entries[i].tool.getActive();
+  for (const entry of entries) {
+    hasActiveTool = hasActiveTool || entry.tool.getActive();
 
-    if (entries[i].defaultTool) {
-      defaultTool = entries[i].tool;
+    if (entry.defaultTool) {
+      defaultTool = entry.tool;
     }
   }
 
diff --git a/src/misc/debounce.js b/src/misc/debounce.js
index d16c8aeb1b3f..5ca7cfc4395a 100644
--- a/src/misc/debounce.js
+++ b/src/misc/debounce.js
@@ -34,10 +34,9 @@ export function debounce(func, wait, invokeApply, $timeout) {
      * @this {any} The context
      */
     function(...args) {
-      const context = this;
-      const later = function() {
+      const later = () => {
         timeout = null;
-        func.apply(context, args);
+        func.apply(this, args);
       };
       if (timeout !== null) {
         $timeout.cancel(timeout);
diff --git a/src/misc/filters.js b/src/misc/filters.js
index 0acf3b0d9cdf..0dca6a63aed1 100644
--- a/src/misc/filters.js
+++ b/src/misc/filters.js
@@ -163,7 +163,7 @@ function NumberFilter($locale) {
         str_number = `0${str_number}`;
       }
       decimal = str_number.substring(str_number.length - nb_decimal);
-      while (decimal[decimal.length - 1] === '0') {
+      while (decimal.endsWith('0')) {
         decimal = decimal.substring(0, decimal.length - 1);
       }
     }
@@ -209,6 +209,7 @@ module.filter('ngeoNumber', NumberFilter);
  * @ngname ngeoUnitPrefix
  */
 function UnitPrefixFilter($filter) {
+  /** @type {function(number, number=): string} */
   const numberFilter = $filter('ngeoNumber');
   const standardPrefix = ['', 'k', 'M', 'G', 'T', 'P'];
   const binaryPrefix = ['', 'Ki', 'Mi', 'Gi', 'Ti', 'Pi'];
diff --git a/src/misc/php-date-formatter.js b/src/misc/php-date-formatter.js
index 5869463e30c7..c4770cb8954b 100644
--- a/src/misc/php-date-formatter.js
+++ b/src/misc/php-date-formatter.js
@@ -23,6 +23,8 @@
 /* eslint default-case: 0 */
 /* eslint prefer-rest-params: 0 */
 /* eslint prefer-template: 0 */
+/* eslint @typescript-eslint/no-this-alias: 0 */
+/* eslint @typescript-eslint/restrict-plus-operands: 0 */
 
 "use strict";
 
@@ -161,6 +163,12 @@ export default class DateFormatter {
         }
         return i;
     }
+    /**
+     *
+     * @param {Date|string|number} vDate
+     * @param {?string} vFormat
+     * @returns {?Date}
+     */
     parseDate(vDate, vFormat) {
         // @ts-ignore: not checked file
         const self = this, vSettings = self.dateSettings,
@@ -237,8 +245,8 @@ export default class DateFormatter {
                     break;
                 case 'g':
                 case 'h':
-                    const vMeriIndex = (vFormatParts.indexOf('a') > -1) ? vFormatParts.indexOf('a') :
-                        (vFormatParts.indexOf('A') > -1) ? vFormatParts.indexOf('A') : -1;
+                    const vMeriIndex = (vFormatParts.includes('a')) ? vFormatParts.indexOf('a') :
+                        (vFormatParts.includes('A')) ? vFormatParts.indexOf('A') : -1;
                     const mer = vDateParts[vMeriIndex];
                     if (vMeriIndex !== -1) {
                         const vMeriOffset = _compare(mer, vSettings.meridiem[0]) ? 0 :
diff --git a/src/offline/Configuration.js b/src/offline/Configuration.js
index bfab27aafde9..4c403af3a552 100644
--- a/src/offline/Configuration.js
+++ b/src/offline/Configuration.js
@@ -22,7 +22,7 @@ import localforage from 'localforage/src/localforage.js';
 /**
  * @implements {ngeox.OfflineOnTileDownload}
  */
-const exports = class extends olObservable {
+export default class extends olObservable {
 
   /**
    * @ngInject
@@ -334,14 +334,13 @@ const exports = class extends olObservable {
    * @return {function(import("ol/ImageTile.js").default, string)} the tile function
    */
   createTileLoadFunction_(offlineLayer) {
-    const that = this;
     /**
      * Load the tile from persistent storage.
      * @param {import("ol/ImageTile.js").default} imageTile The image tile
      * @param {string} src The tile URL
      */
-    const tileLoadFunction = function(imageTile, src) {
-      that.getItem(normalizeURL(src)).then((content) => {
+    const tileLoadFunction = (imageTile, src) => {
+      this.getItem(normalizeURL(src)).then((content) => {
         if (!content) {
           // use a transparent 1x1 image to make the map consistent
           /* eslint-disable-next-line */
@@ -375,7 +374,4 @@ const exports = class extends olObservable {
   getMaxNumberOfParallelDownloads() {
     return 11;
   }
-};
-
-
-export default exports;
+}
diff --git a/src/offline/Downloader.js b/src/offline/Downloader.js
index 1a5574d4e7db..79dfbf7c0cc0 100644
--- a/src/offline/Downloader.js
+++ b/src/offline/Downloader.js
@@ -13,7 +13,7 @@ import angular from 'angular';
 function magnitude2(a, b) {
   let magnitudeSquared = 0;
   for (let i = 0; i < a.length; ++i) {
-    magnitudeSquared += Math.pow(a[1] - b[1], 2);
+    magnitudeSquared += Math.pow(a[i] - b[i], 2);
   }
   return magnitudeSquared;
 }
@@ -77,7 +77,15 @@ const Downloader = class {
       /**
        * @type {number}
        */
-      let minY, maxX, maxY;
+      let minY;
+      /**
+       * @type {number}
+       */
+      let maxX;
+      /**
+       * @type {number}
+       */
+      let maxY;
       tileGrid.forEachTileCoord(extent, z, (coord) => {
         maxX = coord[1];
         maxY = coord[2];
@@ -145,7 +153,7 @@ const Downloader = class {
 
       layerItem.extentByZoom.forEach(obj => {
         const zoom = obj.zoom;
-        if (zooms.indexOf(zoom) < 0) {
+        if (!zooms.includes(zoom)) {
           zooms.push(zoom);
         }
       });
diff --git a/src/print/Utils.js b/src/print/Utils.js
index 454f35863b63..3f1ae91620fb 100644
--- a/src/print/Utils.js
+++ b/src/print/Utils.js
@@ -54,13 +54,11 @@ export const DOTS_PER_INCH = 72;
  * listener.
  */
 PrintUtils.prototype.createPrintMaskPostcompose = function(getSize, getScale, opt_rotation) {
-  const self = this;
-
   return (
     /**
      * @param {Event|import('ol/events/Event.js').default} evt Postcompose event.
      */
-    function(evt) {
+    (evt) => {
       if (evt instanceof RenderEvent && evt.context && evt.frameState) {
         const context = evt.context;
         const frameState = evt.frameState;
@@ -81,10 +79,10 @@ PrintUtils.prototype.createPrintMaskPostcompose = function(getSize, getScale, op
         const ipm = INCHES_PER_METER;
 
         const extentHalfWidth = (((width / ppi) / ipm) * scale / resolution) / 2;
-        self.extentHalfHorizontalDistance_ = (((size[0] / ppi) / ipm) * scale) / 2;
+        this.extentHalfHorizontalDistance_ = (((size[0] / ppi) / ipm) * scale) / 2;
 
         const extentHalfHeight = (((height / ppi) / ipm) * scale / resolution) / 2;
-        self.extentHalfVerticalDistance_ = (((size[1] / ppi) / ipm) * scale) / 2;
+        this.extentHalfVerticalDistance_ = (((size[1] / ppi) / ipm) * scale) / 2;
 
         // Draw a mask on the whole map.
         context.beginPath();
@@ -97,11 +95,11 @@ PrintUtils.prototype.createPrintMaskPostcompose = function(getSize, getScale, op
 
         // Draw the print zone
         if (!opt_rotation) {
-          self.drawPrintZone_(context, center, extentHalfWidth,
+          this.drawPrintZone_(context, center, extentHalfWidth,
             extentHalfHeight);
         } else {
           const rotation = toRadians(opt_rotation());
-          self.drawPrintZoneWithRotation_(context, center, extentHalfWidth,
+          this.drawPrintZoneWithRotation_(context, center, extentHalfWidth,
             extentHalfHeight, rotation);
         }
 
diff --git a/src/profile/d3Elevation.js b/src/profile/d3Elevation.js
index 06445c024e3d..b153aa0c41b4 100644
--- a/src/profile/d3Elevation.js
+++ b/src/profile/d3Elevation.js
@@ -657,7 +657,7 @@ function d3Elevation(options) {
         /**
          * @param {void} d
          */
-        d => pe.sort(d) + (light ? '' : (` - ${pe.title(d)}`))
+        d => `${pe.sort(d)}${(light ? '' : (` - ${pe.title(d)}`))}`
       );
 
     poiEnterG.selectAll('line')
diff --git a/src/statemanager/Location.js b/src/statemanager/Location.js
index 29b0c1019bb8..d4fd4d3609e2 100644
--- a/src/statemanager/Location.js
+++ b/src/statemanager/Location.js
@@ -112,7 +112,7 @@ StatemanagerLocation.prototype.getUriString = function() {
   }
 
   if (this.path_) {
-    if (this.domain_ && this.path_.charAt(0) !== '/') {
+    if (this.domain_ && !this.path_.startsWith('/')) {
       out.push('/');
     }
     out.push(this.path_);
@@ -258,7 +258,7 @@ StatemanagerLocation.prototype.getFragmentParamKeys = function() {
 StatemanagerLocation.prototype.getParamKeysWithPrefix = function(prefix) {
   const keys = [];
   for (const key in this.queryData_) {
-    if (key.indexOf(prefix) == 0) {
+    if (key.startsWith(prefix)) {
       keys.push(key);
     }
   }
@@ -275,7 +275,7 @@ StatemanagerLocation.prototype.getParamKeysWithPrefix = function(prefix) {
 StatemanagerLocation.prototype.getFragmentParamKeysWithPrefix = function(prefix) {
   const keys = [];
   for (const key in this.fragment_) {
-    if (key.indexOf(prefix) == 0) {
+    if (key.startsWith(prefix)) {
       keys.push(key);
     }
   }
diff --git a/src/utils.js b/src/utils.js
index af9978fb75dc..7f21ed69f54b 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -17,7 +17,7 @@ export function getBrowserLanguage(availableLanguages) {
   browserLanguages = browserLanguages.map(item => item.substring(0, 2));
   // remove duplicated language codes
   browserLanguages = browserLanguages.filter((item, index, arr) => arr.indexOf(item) == index);
-  const supportedLanguages = browserLanguages.filter(item => availableLanguages.indexOf(item) != -1);
+  const supportedLanguages = browserLanguages.filter(item => availableLanguages.includes(item));
   return supportedLanguages[0];
 }
 
@@ -56,7 +56,7 @@ export function toMulti(geometry) {
  * @hidden
  */
 export function isSafari() {
-  return navigator.userAgent.indexOf('Safari') != -1 && navigator.userAgent.indexOf('Chrome') == -1;
+  return navigator.userAgent.includes('Safari') && !navigator.userAgent.includes('Chrome');
 }
 
 /**
diff --git a/test/spec/ol-ext/format/featurehash.spec.js b/test/spec/ol-ext/format/featurehash.spec.js
index 1d51ff9fe8c4..e364f96b70cd 100644
--- a/test/spec/ol-ext/format/featurehash.spec.js
+++ b/test/spec/ol-ext/format/featurehash.spec.js
@@ -505,7 +505,7 @@ describe('ngeo.format.FeatureHash', () => {
         fhFormat = new ngeoFormatFeatureHash({
           accuracy: 1,
           properties(feature) {
-            return {foobar: feature.get('foo') + feature.get('bar')};
+            return {foobar: `${feature.get('foo')}${feature.get('bar')}`};
           }
         });
         const feature = new olFeature(new olGeomPoint([1, 1]));