diff --git a/attachment_preview/static/src/js/attachment_preview.js b/attachment_preview/static/src/js/attachment_preview.js
index 3f1f6604..b2c6b339 100644
--- a/attachment_preview/static/src/js/attachment_preview.js
+++ b/attachment_preview/static/src/js/attachment_preview.js
@@ -1,7 +1,7 @@
-///* Copyright 2014 Therp BV (<http://therp.nl>)
-// * License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl). */
+/* Copyright 2014 Therp BV (<http://therp.nl>)
+ * License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl). */
 
-odoo.define('attachment_preview', function(require) {
+odoo.define('attachment_preview', function (require) {
     'use strict';
 
     var core = require('web.core');
@@ -14,16 +14,15 @@ odoo.define('attachment_preview', function(require) {
     var Widget = require('web.Widget');
 
     var AttachmentPreviewMixin = {
-        canPreview: function(extension) {
+        canPreview: function (extension) {
             return $.inArray(
                 extension,
-                [
-                    'odt', 'odp', 'ods', 'fodt', 'pdf', 'ott', 'fodp', 'otp',
-                    'fods', 'ots'
+                ['odt', 'odp', 'ods', 'fodt', 'pdf', 'ott', 'fodp', 'otp',
+                 'fods', 'ots',
                 ]) > -1;
         },
 
-        getUrl: function(attachment_id, attachment_url, attachment_extension, attachment_title) {
+        getUrl: function (attachment_id, attachment_url, attachment_extension, attachment_title) {
             var url = (window.location.origin || '') +
                 '/attachment_preview/static/lib/ViewerJS/index.html' +
                 '?type=' + encodeURIComponent(attachment_extension) +
@@ -33,7 +32,7 @@ odoo.define('attachment_preview', function(require) {
             return url;
         },
 
-        showPreview: function(attachment_id, attachment_url, attachment_extension, attachment_title, split_screen) {
+        showPreview: function (attachment_id, attachment_url, attachment_extension, attachment_title, split_screen) {
             var url = this.getUrl(attachment_id, attachment_url, attachment_extension, attachment_title);
             if (split_screen) {
                 this.trigger_up('onAttachmentPreview', {url: url});
@@ -46,51 +45,51 @@ odoo.define('attachment_preview', function(require) {
     Sidebar.include(AttachmentPreviewMixin);
     Sidebar.include({
         events: _.extend({}, Sidebar.prototype.events, {
-            'click .o_sidebar_preview_attachment': '_onPreviewAttachment'
+            'click .o_sidebar_preview_attachment': '_onPreviewAttachment',
         }),
 
         previewableAttachments: null,
 
         _redraw: function () {
             this._super.apply(this, arguments);
-            this.getPreviewableAttachments().done(function(atts) {
+            this.getPreviewableAttachments().done(function (atts) {
                 this.previewableAttachments = atts;
                 this.updatePreviewButtons(atts);
                 this.trigger_up('setPreviewableAttachments', {attachments: atts});
             }.bind(this));
         },
 
-        _onPreviewAttachment: function(event) {
+        _onPreviewAttachment: function (event) {
             event.preventDefault();
             var self = this,
                 $target = $(event.currentTarget),
-                split_screen = $target.attr('data-target') != 'new',
+                split_screen = $target.attr('data-target') !== 'new',
                 attachment_id = parseInt($target.attr('data-id'), 10),
                 attachment_url = $target.attr('data-url'),
                 attachment_extension = $target.attr('data-extension'),
                 attachment_title = $target.attr('data-original-title');
 
-            if(attachment_extension) {
+            if (attachment_extension) {
                 this.showPreview(attachment_id, attachment_url, attachment_extension, attachment_title, split_screen);
             } else {
                 this._rpc({
                     model: 'ir.attachment',
                     method: 'get_attachment_extension',
-                    args: [attachment_id]
-                }).then(function(extension) {
+                    args: [attachment_id],
+                }).then(function (extension) {
                     self.showPreview(attachment_id, attachment_url, extension, null, split_screen);
                 });
             }
         },
 
-        getPreviewableAttachments: function() {
+        getPreviewableAttachments: function () {
             var self = this;
             var deferred = $.Deferred();
 
             var $items = this.$el.find('.o_sidebar_preview_attachment');
-            var attachments = _.object($items.map(function() {
+            var attachments = _.object($items.map(function () {
                 return parseInt($(this).attr('data-id'), 10);
-            }), $items.map(function() {
+            }), $items.map(function () {
                 return {
                     url: $(this).attr('data-url'),
                     extension: $(this).attr('data-extension'),
@@ -102,14 +101,14 @@ odoo.define('attachment_preview', function(require) {
                 model: 'ir.attachment',
                 method: 'get_attachment_extension',
                 args: [
-                    _.map(_.keys(attachments), function(id) {
+                    _.map(_.keys(attachments), function (id) {
                         return parseInt(id, 10);
-                    })
-                ]
-            }).then(function(extensions) {
-                var reviewableAttachments = _.map(_.keys(_.pick(extensions, function(extension, id) {
+                    }),
+                ],
+            }).then(function (extensions) {
+                var reviewableAttachments = _.map(_.keys(_.pick(extensions, function (extension, id) {
                     return self.canPreview(extension);
-                })), function(id) {
+                })), function (id) {
                     return {
                         id: id,
                         url: attachments[id]['url'],
@@ -120,18 +119,18 @@ odoo.define('attachment_preview', function(require) {
                             attachments[id]['url'],
                             extensions[id],
                             id + ' - ' + attachments[id]['title']
-                        )
-                    }
+                        ),
+                    };
                 });
                 deferred.resolve(reviewableAttachments);
-            }, function() {
+            }, function () {
                 deferred.reject();
             });
             return deferred.promise();
         },
 
-        updatePreviewButtons: function(previewableAttachments) {
-            this.$el.find('.o_sidebar_preview_attachment').each(function() {
+        updatePreviewButtons: function (previewableAttachments) {
+            this.$el.find('.o_sidebar_preview_attachment').each(function () {
                 var $this = $(this);
                 var id = $this.attr('data-id');
                 var att = _.findWhere(previewableAttachments, {id: id});
@@ -147,20 +146,20 @@ odoo.define('attachment_preview', function(require) {
     basic_fields.FieldBinaryFile.include(AttachmentPreviewMixin);
     basic_fields.FieldBinaryFile.include({
         events: _.extend({}, basic_fields.FieldBinaryFile.prototype.events, {
-            'click .fa-search': '_onPreview'
+            'click .fa-search': '_onPreview',
         }),
 
         _renderReadonly: function () {
             var self = this;
             this._super.apply(this, arguments);
-            this._getBinaryExtension().done(function(extension) {
-                if(self.canPreview(extension)) {
+            this._getBinaryExtension().done(function (extension) {
+                if (self.canPreview(extension)) {
                     self._renderPreviewButton(extension);
                 }
             });
         },
 
-        _renderPreviewButton: function(extension) {
+        _renderPreviewButton: function (extension) {
             this.$previewBtn = $("<span/>");
             this.$previewBtn.addClass('fa fa-search');
             this.$previewBtn.attr('title', _.str.sprintf(_t('Preview %s'), this.field.string));
@@ -176,12 +175,12 @@ odoo.define('attachment_preview', function(require) {
                     this.model,
                     this.recordData.id,
                     this.name,
-                    this.attrs.filename
-                ]
+                    this.attrs.filename,
+                ],
             });
         },
 
-        _onPreview: function(event) {
+        _onPreview: function (event) {
             this.showPreview(
                 null,
                 _.str.sprintf(
@@ -194,7 +193,7 @@ odoo.define('attachment_preview', function(require) {
                 _.str.sprintf(_t('Preview %s'), this.field.string),
                 false
             );
-        }
+        },
     });
 
     var AttachmentPreviewWidget = Widget.extend({
@@ -237,7 +236,7 @@ odoo.define('attachment_preview', function(require) {
             window.open(this.attachments[this.activeIndex].previewUrl);
         },
 
-        next: function() {
+        next: function () {
             var index = this.activeIndex + 1;
             if (index >= this.attachments.length) {
                 index = 0;
@@ -247,7 +246,7 @@ odoo.define('attachment_preview', function(require) {
             this.loadPreview();
         },
 
-        previous: function() {
+        previous: function () {
             var index = this.activeIndex - 1;
             if (index < 0) {
                 index = this.attachments.length - 1;
@@ -267,13 +266,13 @@ odoo.define('attachment_preview', function(require) {
             this.trigger('hidden');
         },
 
-        updatePaginator: function() {
+        updatePaginator: function () {
             var value = _.str.sprintf('%s / %s', this.activeIndex + 1, this.attachments.length);
             this.$current.html(value);
         },
 
-        loadPreview: function() {
-            if (this.attachments.length == 0) {
+        loadPreview: function () {
+            if (this.attachments.length === 0) {
                 this.$iframe.attr('src', 'about:blank');
                 return;
             }
@@ -282,18 +281,18 @@ odoo.define('attachment_preview', function(require) {
             this.$iframe.attr('src', att.previewUrl);
         },
 
-        setAttachments: function(attachments) {
+        setAttachments: function (attachments) {
             this.attachments = attachments;
             this.activeIndex = 0;
             this.updatePaginator();
             this.loadPreview();
-        }
+        },
     });
 
     FormRenderer.include({
         attachmentPreviewWidget: null,
 
-        init: function() {
+        init: function () {
             var res = this._super.apply(this, arguments);
             this.attachmentPreviewWidget = new AttachmentPreviewWidget(this);
             this.attachmentPreviewWidget.on('hidden', this, this._attachmentPreviewWidgetHidden);
@@ -305,7 +304,7 @@ odoo.define('attachment_preview', function(require) {
             this.attachmentPreviewWidget.insertAfter(this.$el);
         },
 
-        _attachmentPreviewWidgetHidden: function() {
+        _attachmentPreviewWidgetHidden: function () {
             this.$el.removeClass('attachment_preview');
         },
 
@@ -320,29 +319,29 @@ odoo.define('attachment_preview', function(require) {
         on_detach_callback: function () {
             this.attachmentPreviewWidget.hide();
             return this._super.apply(this, arguments);
-        }
+        },
 
     });
 
     FormController.include({
         custom_events: _.extend({}, FormController.prototype.custom_events, {
             onAttachmentPreview: '_onAttachmentPreview',
-            setPreviewableAttachments: '_setPreviewableAttachments'
+            setPreviewableAttachments: '_setPreviewableAttachments',
         }),
 
         _onAttachmentPreview: function (event) {
             this.renderer.showAttachmentPreviewWidget();
         },
 
-        _setPreviewableAttachments: function(event) {
+        _setPreviewableAttachments: function (event) {
             this.renderer.attachmentPreviewWidget.setAttachments(
                 event.data.attachments
             );
-        }
+        },
     });
 
     return {
         AttachmentPreviewMixin: AttachmentPreviewMixin,
-        AttachmentPreviewWidget: AttachmentPreviewWidget
+        AttachmentPreviewWidget: AttachmentPreviewWidget,
     };
 });
diff --git a/attachment_preview/static/src/js/viewerjs_tweaks.js b/attachment_preview/static/src/js/viewerjs_tweaks.js
index 42f9d836..cd8a0cdc 100644
--- a/attachment_preview/static/src/js/viewerjs_tweaks.js
+++ b/attachment_preview/static/src/js/viewerjs_tweaks.js
@@ -3,9 +3,9 @@
 
 // This file contains tweaks for viewerjs itself and is not meant to be run in
 // OpenERP's context
-(function(original_Viewer) {
-    window.Viewer = function(plugin, parameters) {
-        if(!plugin) {
+(function (original_Viewer) {
+    window.Viewer = function (plugin, parameters) {
+        if (!plugin) {
             // eslint-disable-next-line no-alert
             alert('Unsupported file type');
         }