I need to inherit the reconciliation_renderer.js from account module. What I need to do is to add a new field in the reconciliation model. I already did it from the base module (it works) but my problem is when I apply it in a custom module.

reconciliation_renderer.js (account module)

   /**
 * rendering of the bank statement line, contains line data, proposition and
 * view for 'match' and 'create' mode
 */
var LineRenderer = Widget.extend(FieldManagerMixin, {
    template: "reconciliation.line",
    events: {
        'click .accounting_view caption .o_buttons button': '_onValidate',
        'click .accounting_view thead td': '_onTogglePanel',
        'click .accounting_view tfoot td:not(.cell_left,.cell_right)': '_onShowPanel',
        'click tfoot .cell_left, tfoot .cell_right': '_onSearchBalanceAmount',
        'input input.filter': '_onFilterChange',
        'click .match .load-more a': '_onLoadMore',
        'click .match .mv_line td': '_onSelectMoveLine',
        'click .accounting_view tbody .mv_line td': '_onSelectProposition',
        'click .o_reconcile_models button': '_onQuickCreateProposition',
        'click .create .add_line': '_onCreateProposition',
        'click .accounting_view .line_info_button.fa-exclamation-triangle': '_onTogglePartialReconcile',
        'click .reconcile_model_create': '_onCreateReconcileModel',
        'click .reconcile_model_edit': '_onEditReconcileModel',
        'keyup input': '_onInputKeyup',
        'blur input': '_onInputKeyup',
    },
    custom_events: _.extend({}, FieldManagerMixin.custom_events, {
        'field_changed': '_onFieldChanged',
    }),
    _avoidFieldUpdate: {},

    /**
     * create partner_id field in editable mode
     *
     * @override
     */
    init: function (parent, model, state) {
        this._super(parent);
        FieldManagerMixin.init.call(this);

        this.model = model;
        this._initialState = state;
    },

    /**
     * @override
     */
    start: function () {
        var self = this;
        var def1 = this._makePartnerRecord(this._initialState.st_line.partner_id, this._initialState.st_line.partner_name).then(function (recordID) {
            self.fields = {
                partner_id : new relational_fields.FieldMany2One(self,
                    'partner_id',
                    self.model.get(recordID), {
                        mode: 'edit',
                        attrs: {
                            placeholder: self._initialState.st_line.communication_partner_name || '',
                        }
                    }
                )
            };
            self.fields.partner_id.appendTo(self.$('.accounting_view caption'));
        });
        $('<span class="line_info_button fa fa-info-circle"/>')
            .appendTo(this.$('thead .cell_info_popover'))
            .attr("data-content", qweb.render('reconciliation.line.statement_line.details', {'state': this._initialState}));
        this.$el.popover({
            'selector': '.line_info_button',
            'placement': 'left',
            'container': this.$el,
            'html': true,
            'trigger': 'hover',
            'animation': false,
            'toggle': 'popover'
        });
        var def2 = this._super.apply(this, arguments);
        return $.when(def1, def2);
    },

    //--------------------------------------------------------------------------
    // Public
    //--------------------------------------------------------------------------

    /**
     * update the statement line rendering
     *
     * @param {object} state - statement line
     */
    update: function (state) {
        var self = this;
        // isValid
        this.$('caption .o_buttons button.o_validate').toggleClass('d-none', !!state.balance.type);
        this.$('caption .o_buttons button.o_reconcile').toggleClass('d-none', state.balance.type <= 0);
        this.$('caption .o_buttons .o_no_valid').toggleClass('d-none', state.balance.type >= 0);

        // partner_id
        this._makePartnerRecord(state.st_line.partner_id, state.st_line.partner_name).then(function (recordID) {
            self.fields.partner_id.reset(self.model.get(recordID));
            self.$el.attr('data-partner', state.st_line.partner_id);
        });

        // mode
        this.$('.create, .match').each(function () {
            var $panel = $(this);
            $panel.css('-webkit-transition', 'none');
            $panel.css('-moz-transition', 'none');
            $panel.css('-o-transition', 'none');
            $panel.css('transition', 'none');
            $panel.css('max-height', $panel.height());
            $panel.css('-webkit-transition', '');
            $panel.css('-moz-transition', '');
            $panel.css('-o-transition', '');
            $panel.css('transition', '');
        });
        this.$el.data('mode', state.mode).attr('data-mode', state.mode);
        this.$('.create, .match').each(function () {
            $(this).removeAttr('style');
        });

        // reconciliation_proposition
        var $props = this.$('.accounting_view tbody').empty();

        // Search propositions that could be a partial credit/debit.
        var props = [];
        var partialDebitProp;
        var partialCreditProp;
        var balance = state.balance.amount_currency;
        _.each(state.reconciliation_proposition, function (prop) {
            if (prop.display) {
                props.push(prop);

                /*
                Examples:
                statement line      | 100   |       |
                move line 1         |       | 200   | <- can be a partial of 100
                balance: -100

                statement line      | 500   |       |
                move line 1         |       | 300   | <- is not a eligible to be a partial due to the second line.
                move line 2         |       | 300   | <- can be a partial of 200
                balance: -100

                statement line      | 500   |       |
                move line 1         |       | 700   | <- must not be a partial (debit = 800 > 700 = credit).
                move line 2         | 300   |       |
                balance: 100
                */
                if(!prop.display_new && balance < 0 && prop.amount > 0 && balance + prop.amount > 0)
                    partialDebitProp = prop;
                else if(!prop.display_new && balance > 0 && prop.amount < 0 && balance + prop.amount < 0)
                    partialCreditProp = prop;
            }
        });

        _.each(props, function (line) {
            line.display_triangle = (line.already_paid === false &&
                (((state.balance.amount_currency < 0 || line.partial_reconcile) && partialDebitProp && partialDebitProp === line) ||
                ((state.balance.amount_currency > 0 || line.partial_reconcile) && partialCreditProp && partialCreditProp === line)));
            var $line = $(qweb.render("reconciliation.line.mv_line", {'line': line, 'state': state}));
            if (!isNaN(line.id)) {
                $('<span class="line_info_button fa fa-info-circle"/>')
                    .appendTo($line.find('.cell_info_popover'))
                    .attr("data-content", qweb.render('reconciliation.line.mv_line.details', {'line': line}));
            }
            $props.append($line);
        });

        // mv_lines
        var stateMvLines = state.mv_lines || [];
        var recs_count = stateMvLines.length > 0 ? stateMvLines[0].recs_count : 0;
        var remaining = recs_count - stateMvLines.length;
        var $mv_lines = this.$('.match table tbody').empty();

        _.each(stateMvLines, function (line) {
            var $line = $(qweb.render("reconciliation.line.mv_line", {'line': line, 'state': state}));
            if (!isNaN(line.id)) {
                $('<span class="line_info_button fa fa-info-circle"/>')
                    .appendTo($line.find('.cell_info_popover'))
                    .attr("data-content", qweb.render('reconciliation.line.mv_line.details', {'line': line}));
            }
            $mv_lines.append($line);
        });
        this.$('.match div.load-more').toggle(remaining > 0);
        this.$('.match div.load-more span').text(remaining);
        this.$('.match').css('max-height', !stateMvLines.length && !state.filter.length ? '0px' : '');

        // balance
        this.$('.popover').remove();
        this.$('table tfoot').html(qweb.render("reconciliation.line.balance", {'state': state}));

        // filter
        if (_.str.strip(this.$('input.filter').val()) !== state.filter) {
            this.$('input.filter').val(state.filter);
        }

        // create form
        if (state.createForm) {
            if (!this.fields.account_id) {
                this._renderCreate(state);
            }
            var data = this.model.get(this.handleCreateRecord).data;
            this.model.notifyChanges(this.handleCreateRecord, state.createForm).then(function () {
                // FIXME can't it directly written REPLACE_WITH ids=state.createForm.analytic_tag_ids
                self.model.notifyChanges(self.handleCreateRecord, {analytic_tag_ids: {operation: 'REPLACE_WITH', ids: []}}).then(function (){
                    var defs = [];
                    _.each(state.createForm.analytic_tag_ids, function (tag) {
                        defs.push(self.model.notifyChanges(self.handleCreateRecord, {analytic_tag_ids: {operation: 'ADD_M2M', ids: tag}}));
                    });
                    $.when.apply($, defs).then(function () {
                        var record = self.model.get(self.handleCreateRecord);
                        _.each(self.fields, function (field, fieldName) {
                            if (self._avoidFieldUpdate[fieldName]) return;
                            if (fieldName === "partner_id") return;
                            if ((data[fieldName] || state.createForm[fieldName]) && !_.isEqual(state.createForm[fieldName], data[fieldName])) {
                                field.reset(record);
                            }
                            if (fieldName === 'tax_id') {
                                if (!state.createForm[fieldName] || state.createForm[fieldName].amount_type === "group") {
                                    $('.create_force_tax_included').addClass('d-none');
                                }
                                else {
                                    $('.create_force_tax_included').removeClass('d-none');
                                }
                            } 
                        });
                    });
                });
            });
            if(state.createForm.tax_id){
                // Set the 'Tax Include' field editable or not depending of the 'price_include' value.
                this.$('.create_force_tax_included input').attr('disabled', state.createForm.tax_id.price_include);
            }
        }
        this.$('.create .add_line').toggle(!!state.balance.amount_currency);
    },

    //--------------------------------------------------------------------------
    // Private
    //--------------------------------------------------------------------------

    /**
     * @private
     * @param {jQueryElement} $el
     */
    _destroyPopover: function ($el) {
        var popover = $el.data('bs.popover');
        if (popover) {
            popover.dispose();
        }
    },
    /**
     * @private
     * @param {integer} partnerID
     * @param {string} partnerName
     * @returns {string} local id of the dataPoint
     */
    _makePartnerRecord: function (partnerID, partnerName) {
        var field = {
            relation: 'res.partner',
            type: 'many2one',
            name: 'partner_id',
        };
        if (partnerID) {
            field.value = [partnerID, partnerName];
        }
        return this.model.makeRecord('account.bank.statement.line', [field], {
            partner_id: {
                domain: [["parent_id", "=", false], "|", ["customer", "=", true], ["supplier", "=", true]],
                options: {
                    no_open: true
                }
            }
        });
    },

    /**
     * create account_id, tax_id, analytic_account_id, analytic_tag_ids, label and amount fields
     *
     * @private
     * @param {object} state - statement line
     */
    _renderCreate: function (state) {
        var self = this;
        this.model.makeRecord('account.bank.statement.line', [{
            relation: 'account.account',
            type: 'many2one',
            name: 'account_id',
            domain: [['company_id', '=', state.st_line.company_id]],
        }, {
            relation: 'account.journal',
            type: 'many2one',
            name: 'journal_id',
            domain: [['company_id', '=', state.st_line.company_id]],
        }, {
            relation: 'account.tax',
            type: 'many2one',
            name: 'tax_id',
            domain: [['company_id', '=', state.st_line.company_id]],
        }, {
            relation: 'account.analytic.account',
            type: 'many2one',
            name: 'analytic_account_id',
        }, {
            relation: 'account.analytic.tag',
            type: 'many2many',
            name: 'analytic_tag_ids',
        }, {
            relation: 'account.tax',
            type: 'many2one',
            name: 'withholding_tax_id',
        }, {
            type: 'boolean',
            name: 'force_tax_included',
        }, {
            type: 'char',
            name: 'label',
        }, {
            type: 'float',
            name: 'amount',
        }, {
            type: 'char', //TODO is it a bug or a feature when type date exists ?
            name: 'date',
        }], {
            account_id: {string: _t("Account")},
            label: {string: _t("Label")},
            amount: {string: _t("Account")},
        }).then(function (recordID) {
            self.handleCreateRecord = recordID;
            var record = self.model.get(self.handleCreateRecord);

            self.fields.account_id = new relational_fields.FieldMany2One(self,
                'account_id', record, {mode: 'edit'});

            self.fields.journal_id = new relational_fields.FieldMany2One(self,
                'journal_id', record, {mode: 'edit'});

            self.fields.tax_id = new relational_fields.FieldMany2One(self,
                'tax_id', record, {mode: 'edit', additionalContext: {append_type_to_tax_name: true}});

            self.fields.analytic_account_id = new relational_fields.FieldMany2One(self,
                'analytic_account_id', record, {mode: 'edit'});

            self.fields.analytic_tag_ids = new relational_fields.FieldMany2ManyTags(self,
                'analytic_tag_ids', record, {mode: 'edit'});

            self.fields.withholding_tax_id = new relational_fields.FieldMany2One(self,
                'withholding_tax_id', record, {mode: 'edit'});

            self.fields.force_tax_included = new basic_fields.FieldBoolean(self,
                'force_tax_included', record, {mode: 'edit'});

            self.fields.label = new basic_fields.FieldChar(self,
                'label', record, {mode: 'edit'});

            self.fields.amount = new basic_fields.FieldFloat(self,
                'amount', record, {mode: 'edit'});

            self.fields.date = new basic_fields.FieldDate(self,
                'date', record, {mode: 'edit'});

            var $create = $(qweb.render("reconciliation.line.create", {'state': state}));
            self.fields.account_id.appendTo($create.find('.create_account_id .o_td_field'))
                .then(addRequiredStyle.bind(self, self.fields.account_id));
            self.fields.journal_id.appendTo($create.find('.create_journal_id .o_td_field'));
            self.fields.tax_id.appendTo($create.find('.create_tax_id .o_td_field'));
            self.fields.analytic_account_id.appendTo($create.find('.create_analytic_account_id .o_td_field'));
            self.fields.analytic_tag_ids.appendTo($create.find('.create_analytic_tag_ids .o_td_field'));
            self.fields.withholding_tax_id.appendTo($create.find('.create_withholding_tax_id .o_td_field'));
            self.fields.force_tax_included.appendTo($create.find('.create_force_tax_included .o_td_field'))
            self.fields.label.appendTo($create.find('.create_label .o_td_field'))
                .then(addRequiredStyle.bind(self, self.fields.label));
            self.fields.amount.appendTo($create.find('.create_amount .o_td_field'))
                .then(addRequiredStyle.bind(self, self.fields.amount));
            self.fields.date.appendTo($create.find('.create_date .o_td_field'))
            self.$('.create').append($create);

            function addRequiredStyle(widget) {
                widget.$el.addClass('o_required_modifier');
            }
        });
    },

    //--------------------------------------------------------------------------
    // Handlers
    //--------------------------------------------------------------------------

    /**
     * @private
     * @param {MouseEvent} event
     */
    _onCreateReconcileModel: function (event) {
        event.preventDefault();
        this.do_action({
            type: 'ir.actions.act_window',
            res_model: 'account.reconcile.model',
            views: [[false, 'form']],
            target: 'current'
        });
    },
    /**
     * @private
     * @param {MouseEvent} event
     */
    _onEditReconcileModel: function (event) {
        event.preventDefault();
        this.do_action({
            type: 'ir.actions.act_window',
            res_model: 'account.reconcile.model',
            views: [[false, 'list'], [false, 'form']],
            view_type: "list",
            view_mode: "list",
            target: 'current'
        });
    },
    /**
     * @private
     * @param {OdooEvent} event
     */
    _onFieldChanged: function (event) {
        event.stopPropagation();
        var fieldName = event.target.name;
        if (fieldName === 'partner_id') {
            var partner_id = event.data.changes.partner_id;
            this.trigger_up('change_partner', {'data': partner_id});
        } else {
            if (event.data.changes.amount && isNaN(event.data.changes.amount)) {
                return;
            }
            this.trigger_up('update_proposition', {'data': event.data.changes});
        }
    },
    /**
     * @private
     */
    _onTogglePanel: function () {
        var mode = this.$el.data('mode') === 'inactive' ? 'match' : 'inactive';
        this.trigger_up('change_mode', {'data': mode});
    },
    /**
     * @private
     */
    _onSearchBalanceAmount: function () {
        this.trigger_up('search_balance_amount');
    },
    /**
     * @private
     */
    _onShowPanel: function () {
        var mode = (this.$el.data('mode') === 'inactive' || this.$el.data('mode') === 'match') ? 'create' : 'match';
        this.trigger_up('change_mode', {'data': mode});
    },
    /**
     * @private
     * @param {input event} event
     */
    _onFilterChange: function (event) {
        this.trigger_up('change_filter', {'data': _.str.strip($(event.target).val())});
    },
    /**
     * @private
     * @param {keyup event} event
     */
    _onInputKeyup: function (event) {
        var target_partner_id = $(event.target).parents('[name="partner_id"]');
        if (target_partner_id.length === 1) {
            return;
        }
        if(event.keyCode === 13) {
            var created_lines = _.findWhere(this.model.lines, {mode: 'create'});
            if (created_lines && created_lines.balance.amount) {
                this._onCreateProposition();
            }
            return;
        }

        var self = this;
        for (var fieldName in this.fields) {
            var field = this.fields[fieldName];
            if (!field.$el.is(event.target)) {
                continue;
            }
            this._avoidFieldUpdate[field.name] = event.type !== 'focusout';
            field.value = false;
            field._setValue($(event.target).val()).then(function () {
                self._avoidFieldUpdate[field.name] = false;
            });
            break;
        }
    },
    /**
     * @private
     */
    _onLoadMore: function (ev) {
        ev.preventDefault();
        this.trigger_up('change_offset', {'data': 1});
    },
    /**
     * @private
     * @param {MouseEvent} event
     */
    _onSelectMoveLine: function (event) {
        var $el = $(event.target);
        this._destroyPopover($el);
        var moveLineId = $el.closest('.mv_line').data('line-id');
        this.trigger_up('add_proposition', {'data': moveLineId});
    },
    /**
     * @private
     * @param {MouseEvent} event
     */
    _onSelectProposition: function (event) {
        var $el = $(event.target);
        this._destroyPopover($el);
        var moveLineId = $el.closest('.mv_line').data('line-id');
        this.trigger_up('remove_proposition', {'data': moveLineId});
    },
    /**
     * @private
     * @param {MouseEvent} event
     */
    _onQuickCreateProposition: function (event) {
        document.activeElement && document.activeElement.blur();
        this.trigger_up('quick_create_proposition', {'data': $(event.target).data('reconcile-model-id')});
    },
    /**
     * @private
     */
    _onCreateProposition: function () {
        document.activeElement && document.activeElement.blur();
        var invalid = [];
        _.each(this.fields, function (field) {
            if (!field.isValid()) {
                invalid.push(field.string);
            }
        });
        if (invalid.length) {
            this.do_warn(_t("Some fields are undefined"), invalid.join(', '));
            return;
        }
        this.trigger_up('create_proposition');
    },
    /**
     * @private
     */
    _onValidate: function () {
        this.trigger_up('validate');
    },
    /**
     * @private
     * @param {MouseEvent} event
     */
    _onTogglePartialReconcile: function (e) {
        e.stopPropagation();
        var popover = $(e.target).data('bs.popover');
        popover && popover.dispose();
        this.trigger_up('toggle_partial_reconcile');
    }
});

My XML for calling the JS file:

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <data>
        <template id="assets_backend" name="account assets" inherit_id="web.assets_backend">
            <xpath expr="." position="inside">
                <script type="text/javascript" src="/my_module/static/src/js/reconciliation_renderer.js"></script>
            </xpath>
        </template>
    </data>
</odoo>

I need to inherit the _renderCreate function to add my new field. This is my current JS file. I'm not quite familiar with JavaScript that's why I'm not sure if it's the correct way of inheriting.

odoo.define('my_module.new_field_computation', function (require) {
    "use strict"; 
var Widget = require('web.Widget');
var FieldManagerMixin = require('web.FieldManagerMixin');
var relational_fields = require('web.relational_fields');
var basic_fields = require('web.basic_fields');
var core = require('web.core');
var time = require('web.time');
var session = require('web.session');
var qweb = core.qweb;
var _t = core._t;
var LineRenderer = require('reconciliation.line');

//ADD FIELDS
LineRenderer.include({
    init: function (parent, model, state) {
    this._super(parent);
    FieldManagerMixin.init.call(this);

    this.model = model;
    this._initialState = state;
        var form_fields = this._renderCreate(state);

    _renderCreate: function (state) {
        var self = this;
        this.model.makeRecord('account.bank.statement.line', [{
            relation: 'account.tax',
            type: 'many2one',
            name: 'new_field',
            domain: [['amount', '<', 0.0]],

        }].{
        }).then(function (recordID) {
            self.handleCreateRecord = recordID;
            var record = self.model.get(self.handleCreateRecord);

            self.fields.new_field = new relational_fields.FieldMany2One(self,
                'new_field', record, {mode: 'edit'});

             var $create = $(qweb.render("reconciliation.line.create", {'state': state}));
             self.fields.withholding_tax_id.appendTo($create.find('.create_new_field .o_td_field'));
                             self.$('.create').append($create);

                function addRequiredStyle(widget) {
                widget.$el.addClass('o_required_modifier');



            }
        });
        },

        this._renderCreate(state) = form_fields;
    } 
});