diff --git a/attachment_preview/__manifest__.py b/attachment_preview/__manifest__.py
index 32827993..050b1668 100644
--- a/attachment_preview/__manifest__.py
+++ b/attachment_preview/__manifest__.py
@@ -4,21 +4,16 @@
 {
     "name": "Preview attachments",
     "version": "12.0.1.0.2",
-    "author": "Therp BV,"
-              "Onestein,"
-              "Odoo Community Association (OCA)",
+    "author": "Therp BV," "Onestein," "Odoo Community Association (OCA)",
     "license": "AGPL-3",
-    "summary": 'Preview attachments supported by Viewer.js',
+    "summary": "Preview attachments supported by Viewer.js",
     "category": "Knowledge Management",
-    "depends": [
-        'web',
-        'mail'
-    ],
+    "depends": ["web", "mail"],
     "data": [
         "templates/assets.xml",
     ],
     "qweb": [
-        'static/src/xml/attachment_preview.xml',
+        "static/src/xml/attachment_preview.xml",
     ],
     "installable": True,
 }
diff --git a/attachment_preview/models/ir_attachment.py b/attachment_preview/models/ir_attachment.py
index 0b88b0e7..a24cb4cc 100644
--- a/attachment_preview/models/ir_attachment.py
+++ b/attachment_preview/models/ir_attachment.py
@@ -6,70 +6,71 @@ import logging
 import mimetypes
 import os.path
 
-from odoo import models, api
+from odoo import api, models
 
 _logger = logging.getLogger(__name__)
 
 
 class IrAttachment(models.Model):
-    _inherit = 'ir.attachment'
+    _inherit = "ir.attachment"
 
     @api.model
-    def get_binary_extension(self, model, ids, binary_field,
-                             filename_field=None):
+    def get_binary_extension(self, model, ids, binary_field, filename_field=None):
         result = {}
         ids_to_browse = ids if isinstance(ids, collections.Iterable) else [ids]
 
         # First pass: load fields in bin_size mode to avoid loading big files
         #  unnecessarily.
         if filename_field:
-            for this in self.env[model].with_context(
-                    bin_size=True).browse(ids_to_browse):
+            for this in (
+                self.env[model].with_context(bin_size=True).browse(ids_to_browse)
+            ):
                 if not this.id:
                     result[this.id] = False
                     continue
-                extension = ''
+                extension = ""
                 if this[filename_field]:
-                    filename, extension = os.path.splitext(
-                        this[filename_field])
+                    filename, extension = os.path.splitext(this[filename_field])
                 if this[binary_field] and extension:
                     result[this.id] = extension
-                    _logger.debug('Got extension %s from filename %s',
-                                  extension, this[filename_field])
+                    _logger.debug(
+                        "Got extension %s from filename %s",
+                        extension,
+                        this[filename_field],
+                    )
         # Second pass for all attachments which have to be loaded fully
         #  to get the extension from the content
         ids_to_browse = [_id for _id in ids_to_browse if _id not in result]
-        for this in self.env[model].with_context(
-                bin_size=True).browse(ids_to_browse):
+        for this in self.env[model].with_context(bin_size=True).browse(ids_to_browse):
             if not this[binary_field]:
                 result[this.id] = False
                 continue
             try:
                 import magic
-                if model == self._name and binary_field == 'datas'\
-                        and this.store_fname:
+
+                if model == self._name and binary_field == "datas" and this.store_fname:
                     mimetype = magic.from_file(
-                        this._full_path(this.store_fname), mime=True)
-                    _logger.debug('Magic determined mimetype %s from file %s',
-                                  mimetype, this.store_fname)
+                        this._full_path(this.store_fname), mime=True
+                    )
+                    _logger.debug(
+                        "Magic determined mimetype %s from file %s",
+                        mimetype,
+                        this.store_fname,
+                    )
                 else:
-                    mimetype = magic.from_buffer(
-                        this[binary_field], mime=True)
-                    _logger.debug('Magic determined mimetype %s from buffer',
-                                  mimetype)
+                    mimetype = magic.from_buffer(this[binary_field], mime=True)
+                    _logger.debug("Magic determined mimetype %s from buffer", mimetype)
             except ImportError:
                 (mimetype, encoding) = mimetypes.guess_type(
-                    'data:;base64,' + this[binary_field], strict=False)
-                _logger.debug('Mimetypes guessed type %s from buffer',
-                              mimetype)
-            extension = mimetypes.guess_extension(
-                mimetype.split(';')[0], strict=False)
+                    "data:;base64," + this[binary_field], strict=False
+                )
+                _logger.debug("Mimetypes guessed type %s from buffer", mimetype)
+            extension = mimetypes.guess_extension(mimetype.split(";")[0], strict=False)
             result[this.id] = extension
         for _id in result:
-            result[_id] = (result[_id] or '').lstrip('.').lower()
+            result[_id] = (result[_id] or "").lstrip(".").lower()
         return result if isinstance(ids, collections.Iterable) else result[ids]
 
     @api.model
     def get_attachment_extension(self, ids):
-        return self.get_binary_extension(
-            self._name, ids, 'datas', 'datas_fname')
+        return self.get_binary_extension(self._name, ids, "datas", "datas_fname")
diff --git a/attachment_preview/static/src/js/attachment_preview.js b/attachment_preview/static/src/js/attachment_preview.js
index 85413877..80340a6a 100644
--- a/attachment_preview/static/src/js/attachment_preview.js
+++ b/attachment_preview/static/src/js/attachment_preview.js
@@ -1,41 +1,69 @@
 /* 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) {
-    'use strict';
+odoo.define("attachment_preview", function (require) {
+    "use strict";
 
-    var core = require('web.core');
+    var core = require("web.core");
     var _t = core._t;
     var qweb = core.qweb;
-    var Chatter = require('mail.Chatter');
-    var basic_fields = require('web.basic_fields');
-    var FormRenderer = require('web.FormRenderer');
-    var FormController = require('web.FormController');
-    var Widget = require('web.Widget');
+    var Chatter = require("mail.Chatter");
+    var basic_fields = require("web.basic_fields");
+    var FormRenderer = require("web.FormRenderer");
+    var FormController = require("web.FormController");
+    var Widget = require("web.Widget");
 
     var AttachmentPreviewMixin = {
         canPreview: function (extension) {
-            return $.inArray(
-                extension,
-                ['odt', 'odp', 'ods', 'fodt', 'pdf', 'ott', 'fodp', 'otp',
-                 'fods', 'ots',
-                ]) > -1;
+            return (
+                $.inArray(extension, [
+                    "odt",
+                    "odp",
+                    "ods",
+                    "fodt",
+                    "pdf",
+                    "ott",
+                    "fodp",
+                    "otp",
+                    "fods",
+                    "ots",
+                ]) > -1
+            );
         },
 
-        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) +
-                '&title=' + encodeURIComponent(attachment_title) +
-                '#' +
-                attachment_url.replace(window.location.origin, '');
+        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) +
+                "&title=" +
+                encodeURIComponent(attachment_title) +
+                "#" +
+                attachment_url.replace(window.location.origin, "");
             return url;
         },
 
-        showPreview: function (attachment_id, attachment_url, attachment_extension, attachment_title, split_screen) {
-            var url = this.getUrl(attachment_id, attachment_url, attachment_extension, attachment_title);
+        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});
+                this.trigger_up("onAttachmentPreview", {url: url});
             } else {
                 window.open(url);
             }
@@ -45,7 +73,7 @@ odoo.define('attachment_preview', function (require) {
     Chatter.include(AttachmentPreviewMixin);
     Chatter.include({
         events: _.extend({}, Chatter.prototype.events, {
-            'click .o_attachment_preview': '_onPreviewAttachment',
+            "click .o_attachment_preview": "_onPreviewAttachment",
         }),
 
         previewableAttachments: null,
@@ -53,11 +81,13 @@ odoo.define('attachment_preview', function (require) {
         _openAttachmentBox: function () {
             var res = this._super.apply(this, arguments);
 
-            this.getPreviewableAttachments().done(function (atts) {
-                this.previewableAttachments = atts;
-                this.updatePreviewButtons(atts);
-                this.getParent().attachmentPreviewWidget.setAttachments(atts);
-            }.bind(this));
+            this.getPreviewableAttachments().done(
+                function (atts) {
+                    this.previewableAttachments = atts;
+                    this.updatePreviewButtons(atts);
+                    this.getParent().attachmentPreviewWidget.setAttachments(atts);
+                }.bind(this)
+            );
 
             return res;
         },
@@ -65,7 +95,7 @@ odoo.define('attachment_preview', function (require) {
         update: function () {
             var res = this._super.apply(this, arguments);
             var self = this;
-            if (this.getParent().$el.hasClass('attachment_preview')) {
+            if (this.getParent().$el.hasClass("attachment_preview")) {
                 this._fetchAttachments().done(function () {
                     self._openAttachmentBox();
                     self.getPreviewableAttachments().done(function (atts) {
@@ -82,21 +112,33 @@ odoo.define('attachment_preview', function (require) {
             event.preventDefault();
             var self = this,
                 $target = $(event.currentTarget),
-                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');
+                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) {
-                this.showPreview(attachment_id, attachment_url, attachment_extension, attachment_title, split_screen);
+                this.showPreview(
+                    attachment_id,
+                    attachment_url,
+                    attachment_extension,
+                    attachment_title,
+                    split_screen
+                );
             } else {
                 this._rpc({
-                    model: 'ir.attachment',
-                    method: 'get_attachment_extension',
+                    model: "ir.attachment",
+                    method: "get_attachment_extension",
                     args: [attachment_id],
                 }).then(function (extension) {
-                    self.showPreview(attachment_id, attachment_url, extension, null, split_screen);
+                    self.showPreview(
+                        attachment_id,
+                        attachment_url,
+                        extension,
+                        null,
+                        split_screen
+                    );
                 });
             }
         },
@@ -105,56 +147,67 @@ odoo.define('attachment_preview', function (require) {
             var self = this;
             var deferred = $.Deferred();
 
-            var $items = this.$el.find('.o_attachment_preview');
-            var attachments = _.object($items.map(function () {
-                return parseInt($(this).attr('data-id'), 10);
-            }), $items.map(function () {
-                return {
-                    url: $(this).attr('data-url'),
-                    extension: $(this).attr('data-extension'),
-                    title: $(this).attr('data-original-title'),
-                };
-            }));
+            var $items = this.$el.find(".o_attachment_preview");
+            var attachments = _.object(
+                $items.map(function () {
+                    return parseInt($(this).attr("data-id"), 10);
+                }),
+                $items.map(function () {
+                    return {
+                        url: $(this).attr("data-url"),
+                        extension: $(this).attr("data-extension"),
+                        title: $(this).attr("data-original-title"),
+                    };
+                })
+            );
 
             this._rpc({
-                model: 'ir.attachment',
-                method: 'get_attachment_extension',
+                model: "ir.attachment",
+                method: "get_attachment_extension",
                 args: [
                     _.map(_.keys(attachments), function (id) {
                         return parseInt(id, 10);
                     }),
                 ],
-            }).then(function (extensions) {
-                var reviewableAttachments = _.map(_.keys(_.pick(extensions, function (extension, id) {
-                    return self.canPreview(extension);
-                })), function (id) {
-                    return {
-                        id: id,
-                        url: attachments[id].url,
-                        extension: extensions[id],
-                        title: attachments[id].title,
-                        previewUrl: self.getUrl(
-                            id,
-                            attachments[id].url,
-                            extensions[id],
-                            id + ' - ' + attachments[id].title
+            }).then(
+                function (extensions) {
+                    var reviewableAttachments = _.map(
+                        _.keys(
+                            _.pick(extensions, function (extension, id) {
+                                return self.canPreview(extension);
+                            })
                         ),
-                    };
-                });
-                deferred.resolve(reviewableAttachments);
-            }, function () {
-                deferred.reject();
-            });
+                        function (id) {
+                            return {
+                                id: id,
+                                url: attachments[id].url,
+                                extension: extensions[id],
+                                title: attachments[id].title,
+                                previewUrl: self.getUrl(
+                                    id,
+                                    attachments[id].url,
+                                    extensions[id],
+                                    id + " - " + attachments[id].title
+                                ),
+                            };
+                        }
+                    );
+                    deferred.resolve(reviewableAttachments);
+                },
+                function () {
+                    deferred.reject();
+                }
+            );
             return deferred.promise();
         },
 
         updatePreviewButtons: function (previewableAttachments) {
-            this.$el.find('.o_attachment_preview').each(function () {
+            this.$el.find(".o_attachment_preview").each(function () {
                 var $this = $(this);
-                var id = $this.attr('data-id');
+                var id = $this.attr("data-id");
                 var att = _.findWhere(previewableAttachments, {id: id});
                 if (att) {
-                    $this.attr('data-extension', att.extension);
+                    $this.attr("data-extension", att.extension);
                 } else {
                     $this.remove();
                 }
@@ -165,7 +218,7 @@ 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 () {
@@ -183,23 +236,21 @@ odoo.define('attachment_preview', function (require) {
 
         _renderPreviewButton: function (extension) {
             this.$previewBtn = $("<a/>");
-            this.$previewBtn.addClass('fa fa-search mr-2');
-            this.$previewBtn.attr('href', 'javascript:void(0)');
-            this.$previewBtn.attr('title', _.str.sprintf(_t('Preview %s'), this.field.string));
-            this.$previewBtn.attr('data-extension', extension);
-            this.$el.find('.fa-download').before(this.$previewBtn);
+            this.$previewBtn.addClass("fa fa-search mr-2");
+            this.$previewBtn.attr("href", "javascript:void(0)");
+            this.$previewBtn.attr(
+                "title",
+                _.str.sprintf(_t("Preview %s"), this.field.string)
+            );
+            this.$previewBtn.attr("data-extension", extension);
+            this.$el.find(".fa-download").before(this.$previewBtn);
         },
 
         _getBinaryExtension: function () {
             return this._rpc({
-                model: 'ir.attachment',
-                method: 'get_binary_extension',
-                args: [
-                    this.model,
-                    this.recordData.id,
-                    this.name,
-                    this.attrs.filename,
-                ],
+                model: "ir.attachment",
+                method: "get_binary_extension",
+                args: [this.model, this.recordData.id, this.name, this.attrs.filename],
             });
         },
 
@@ -207,13 +258,13 @@ odoo.define('attachment_preview', function (require) {
             this.showPreview(
                 null,
                 _.str.sprintf(
-                    '/web/content?model=%s&field=%s&id=%d',
+                    "/web/content?model=%s&field=%s&id=%d",
                     this.model,
                     this.name,
                     this.recordData.id
                 ),
-                $(event.currentTarget).attr('data-extension'),
-                _.str.sprintf(_t('Preview %s'), this.field.string),
+                $(event.currentTarget).attr("data-extension"),
+                _.str.sprintf(_t("Preview %s"), this.field.string),
                 false
             );
             event.stopPropagation();
@@ -221,22 +272,22 @@ odoo.define('attachment_preview', function (require) {
     });
 
     var AttachmentPreviewWidget = Widget.extend({
-        template: 'attachment_preview.AttachmentPreviewWidget',
+        template: "attachment_preview.AttachmentPreviewWidget",
         activeIndex: 0,
         attachments: null,
 
         events: {
-            'click .attachment_preview_close': '_onCloseClick',
-            'click .attachment_preview_previous': '_onPreviousClick',
-            'click .attachment_preview_next': '_onNextClick',
-            'click .attachment_preview_popout': '_onPopoutClick',
+            "click .attachment_preview_close": "_onCloseClick",
+            "click .attachment_preview_previous": "_onPreviousClick",
+            "click .attachment_preview_next": "_onNextClick",
+            "click .attachment_preview_popout": "_onPopoutClick",
         },
 
         start: function () {
             var res = this._super.apply(this, arguments);
-            this.$overlay = this.$el.find('.attachment_preview_overlay');
-            this.$iframe = this.$el.find('.attachment_preview_iframe');
-            this.$current = this.$el.find('.attachment_preview_current');
+            this.$overlay = this.$el.find(".attachment_preview_overlay");
+            this.$iframe = this.$el.find(".attachment_preview_iframe");
+            this.$current = this.$el.find(".attachment_preview_current");
             return res;
         },
 
@@ -281,28 +332,32 @@ odoo.define('attachment_preview', function (require) {
         },
 
         show: function () {
-            this.$el.removeClass('d-none');
-            this.trigger('shown');
+            this.$el.removeClass("d-none");
+            this.trigger("shown");
         },
 
         hide: function () {
-            this.$el.addClass('d-none');
-            this.trigger('hidden');
+            this.$el.addClass("d-none");
+            this.trigger("hidden");
         },
 
         updatePaginator: function () {
-            var value = _.str.sprintf('%s / %s', this.activeIndex + 1, this.attachments.length);
+            var value = _.str.sprintf(
+                "%s / %s",
+                this.activeIndex + 1,
+                this.attachments.length
+            );
             this.$current.html(value);
         },
 
         loadPreview: function () {
             if (this.attachments.length === 0) {
-                this.$iframe.attr('src', 'about:blank');
+                this.$iframe.attr("src", "about:blank");
                 return;
             }
 
             var att = this.attachments[this.activeIndex];
-            this.$iframe.attr('src', att.previewUrl);
+            this.$iframe.attr("src", att.previewUrl);
         },
 
         setAttachments: function (attachments) {
@@ -315,7 +370,7 @@ odoo.define('attachment_preview', function (require) {
 
     FormRenderer.include({
         custom_events: _.extend({}, FormRenderer.prototype.custom_events, {
-            onAttachmentPreview: '_onAttachmentPreview',
+            onAttachmentPreview: "_onAttachmentPreview",
         }),
 
         attachmentPreviewWidget: null,
@@ -323,7 +378,11 @@ odoo.define('attachment_preview', function (require) {
         init: function () {
             var res = this._super.apply(this, arguments);
             this.attachmentPreviewWidget = new AttachmentPreviewWidget(this);
-            this.attachmentPreviewWidget.on('hidden', this, this._attachmentPreviewWidgetHidden);
+            this.attachmentPreviewWidget.on(
+                "hidden",
+                this,
+                this._attachmentPreviewWidgetHidden
+            );
             return res;
         },
 
@@ -335,11 +394,11 @@ odoo.define('attachment_preview', function (require) {
         },
 
         _attachmentPreviewWidgetHidden: function () {
-            this.$el.removeClass('attachment_preview');
+            this.$el.removeClass("attachment_preview");
         },
 
         showAttachmentPreviewWidget: function () {
-            this.$el.addClass('attachment_preview');
+            this.$el.addClass("attachment_preview");
 
             this.attachmentPreviewWidget.setAttachments(
                 this.chatter.previewableAttachments
@@ -357,7 +416,6 @@ odoo.define('attachment_preview', function (require) {
         },
     });
 
-
     return {
         AttachmentPreviewMixin: AttachmentPreviewMixin,
         AttachmentPreviewWidget: AttachmentPreviewWidget,
diff --git a/attachment_preview/static/src/js/viewerjs_tweaks.js b/attachment_preview/static/src/js/viewerjs_tweaks.js
index cd8a0cdc..ad745646 100644
--- a/attachment_preview/static/src/js/viewerjs_tweaks.js
+++ b/attachment_preview/static/src/js/viewerjs_tweaks.js
@@ -7,8 +7,8 @@
     window.Viewer = function (plugin, parameters) {
         if (!plugin) {
             // eslint-disable-next-line no-alert
-            alert('Unsupported file type');
+            alert("Unsupported file type");
         }
         return original_Viewer(plugin, parameters);
     };
-}(window.Viewer));
+})(window.Viewer);
diff --git a/attachment_preview/static/src/scss/attachment_preview.scss b/attachment_preview/static/src/scss/attachment_preview.scss
index 9c2bf904..354cabe8 100644
--- a/attachment_preview/static/src/scss/attachment_preview.scss
+++ b/attachment_preview/static/src/scss/attachment_preview.scss
@@ -44,7 +44,7 @@
         padding: 4px;
         float: left;
         width: 100%;
-        background-color: #FFF;
+        background-color: #fff;
         border-left: 1px solid $gray-800;
 
         button {
diff --git a/attachment_preview/static/src/xml/attachment_preview.xml b/attachment_preview/static/src/xml/attachment_preview.xml
index da3f10f5..a505f885 100644
--- a/attachment_preview/static/src/xml/attachment_preview.xml
+++ b/attachment_preview/static/src/xml/attachment_preview.xml
@@ -1,19 +1,23 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8" ?>
 <templates>
     <t t-extend="mail.Attachment">
         <t t-jquery=".o_attachment_download" t-operation="after">
-            <span t-if="!attachment.callback and attachment.url"
-                  class="fa fa-search ml4 o_attachment_preview"
-                  t-att-data-id="attachment.id"
-                  t-att-data-url="attachment.url"
-                  t-attf-title="Preview #{attachment.name} in side panel"/>
+            <span
+                t-if="!attachment.callback and attachment.url"
+                class="fa fa-search ml4 o_attachment_preview"
+                t-att-data-id="attachment.id"
+                t-att-data-url="attachment.url"
+                t-attf-title="Preview #{attachment.name} in side panel"
+            />
 
-            <span t-if="!attachment.callback and attachment.url"
-                  class="fa fa-external-link ml4 o_attachment_preview o_attachment_preview_new_tab"
-                  data-target="new"
-                  t-att-data-id="attachment.id"
-                  t-att-data-url="attachment.url"
-                  t-attf-title="Open preview #{attachment.name} in a new tab"/>
+            <span
+                t-if="!attachment.callback and attachment.url"
+                class="fa fa-external-link ml4 o_attachment_preview o_attachment_preview_new_tab"
+                data-target="new"
+                t-att-data-id="attachment.id"
+                t-att-data-url="attachment.url"
+                t-attf-title="Open preview #{attachment.name} in a new tab"
+            />
         </t>
     </t>
 
@@ -21,15 +25,25 @@
         <div class="attachment_preview_widget d-none">
             <div class="attachment_preview_buttons">
                 <div class="button-group pull-left">
-                    <button class="btn btn-sm btn-secondary attachment_preview_previous"><i class="fa fa-chevron-left"/></button>
-                    <button class="btn btn-sm btn-secondary disabled attachment_preview_current">1 / 5</button>
-                    <button class="btn btn-sm btn-secondary attachment_preview_next"><i class="fa fa-chevron-right"/></button>
+                    <button
+                        class="btn btn-sm btn-secondary attachment_preview_previous"
+                    ><i class="fa fa-chevron-left" /></button>
+                    <button
+                        class="btn btn-sm btn-secondary disabled attachment_preview_current"
+                    >1 / 5</button>
+                    <button class="btn btn-sm btn-secondary attachment_preview_next"><i
+                            class="fa fa-chevron-right"
+                        /></button>
                 </div>
-                <button class="btn btn-sm btn-secondary pull-left ml8 attachment_preview_popout"><i class="fa fa-external-link"/></button>
+                <button
+                    class="btn btn-sm btn-secondary pull-left ml8 attachment_preview_popout"
+                ><i class="fa fa-external-link" /></button>
 
-                <button class="btn btn-sm btn-secondary pull-right attachment_preview_close"><i class="fa fa-times"/></button>
+                <button
+                    class="btn btn-sm btn-secondary pull-right attachment_preview_close"
+                ><i class="fa fa-times" /></button>
             </div>
-            <iframe class="attachment_preview_iframe"></iframe>
+            <iframe class="attachment_preview_iframe" />
         </div>
     </t>
 </templates>
diff --git a/attachment_preview/templates/assets.xml b/attachment_preview/templates/assets.xml
index e6678b3d..883c1fb2 100644
--- a/attachment_preview/templates/assets.xml
+++ b/attachment_preview/templates/assets.xml
@@ -1,9 +1,20 @@
-<?xml version="1.0" encoding="UTF-8"?>
+<?xml version="1.0" encoding="UTF-8" ?>
 <odoo>
-    <template id="assets_backend" name="attachment_preview assets" inherit_id="web.assets_backend">
+    <template
+        id="assets_backend"
+        name="attachment_preview assets"
+        inherit_id="web.assets_backend"
+    >
         <xpath expr="." position="inside">
-            <script type="text/javascript" src="/attachment_preview/static/src/js/attachment_preview.js"></script>
-            <link rel="stylesheet" type="text/scss" href="/attachment_preview/static/src/scss/attachment_preview.scss" />
+            <script
+                type="text/javascript"
+                src="/attachment_preview/static/src/js/attachment_preview.js"
+            />
+            <link
+                rel="stylesheet"
+                type="text/scss"
+                href="/attachment_preview/static/src/scss/attachment_preview.scss"
+            />
         </xpath>
     </template>
 </odoo>
diff --git a/attachment_preview/tests/test_attachment_preview.py b/attachment_preview/tests/test_attachment_preview.py
index 17e731b7..bbd023da 100644
--- a/attachment_preview/tests/test_attachment_preview.py
+++ b/attachment_preview/tests/test_attachment_preview.py
@@ -2,45 +2,44 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 
 import base64
+
 from odoo.tests.common import TransactionCase
 
 
 class TestAttachmentPreview(TransactionCase):
     def test_get_extension(self):
-        attachment = self.env['ir.attachment'].create({
-            'datas': base64.b64encode(b'from this, to that.'),
-            'name': 'doc.txt',
-            'datas_fname': 'doc.txt'
-        })
-        attachment2 = self.env['ir.attachment'].create({
-            'datas': base64.b64encode(b'Png'),
-            'name': 'image.png',
-            'datas_fname': 'image.png'
-        })
-        res = self.env['ir.attachment'].get_attachment_extension(
-            attachment.id
+        attachment = self.env["ir.attachment"].create(
+            {
+                "datas": base64.b64encode(b"from this, to that."),
+                "name": "doc.txt",
+                "datas_fname": "doc.txt",
+            }
         )
-        self.assertEqual(res, 'txt')
+        attachment2 = self.env["ir.attachment"].create(
+            {
+                "datas": base64.b64encode(b"Png"),
+                "name": "image.png",
+                "datas_fname": "image.png",
+            }
+        )
+        res = self.env["ir.attachment"].get_attachment_extension(attachment.id)
+        self.assertEqual(res, "txt")
 
-        res = self.env['ir.attachment'].get_attachment_extension(
+        res = self.env["ir.attachment"].get_attachment_extension(
             [attachment.id, attachment2.id]
         )
-        self.assertEqual(res[attachment.id], 'txt')
-        self.assertEqual(res[attachment2.id], 'png')
+        self.assertEqual(res[attachment.id], "txt")
+        self.assertEqual(res[attachment2.id], "png")
 
-        res2 = self.env['ir.attachment'].get_binary_extension(
-            'ir.attachment',
-            attachment.id,
-            'datas'
+        res2 = self.env["ir.attachment"].get_binary_extension(
+            "ir.attachment", attachment.id, "datas"
         )
         self.assertTrue(res2)
 
-        module = self.env['ir.module.module'].search([]).filtered(
-            lambda m: m.icon_image
-        )[0]
-        res3 = self.env['ir.attachment'].get_binary_extension(
-            'ir.module.module',
-            module.id,
-            'icon_image'
+        module = (
+            self.env["ir.module.module"].search([]).filtered(lambda m: m.icon_image)[0]
+        )
+        res3 = self.env["ir.attachment"].get_binary_extension(
+            "ir.module.module", module.id, "icon_image"
         )
         self.assertTrue(res3)