Obsidian QuickAdd script that opens & auto-updates today's daily note in the right sidebar.

pin-daily-note-in-sidebar.js

module.exports = async (params) => {
    const { app, obsidian } = params;

    // Create WorkspaceLeaf (a tab in the right sidebar) which today's daily note will be opened in
    const leaf = app.workspace.getRightLeaf(false);
    // Open today's daily note in the leaf
    await updateLeafFile(leaf, app, obsidian);
    // Show the leaf (tab in sidebar)
    app.workspace.revealLeaf(leaf);


    /** Auto-update mechanism that will be disabled when closing the leaf (tab) */

    // the component that manages the auto-updater's lifecycle
    const component = new obsidian.Component();
    component.load();

    // unload the component & detach the leaf when the tab is closed
    component.registerEvent(
        app.workspace.on('layout-change', () => {
            if (leaf.parent === null) {
                leaf.detach();
                component.unload();
            }
        })
    );

    // register auto-update of the daily note opened in the sidebar
    const reserveUpdate = () => {
        const now = obsidian.moment();
        const tomorrow = obsidian.moment().add(1, 'days').startOf('day');
        const delay = tomorrow - now;
        setTimeout(() => updateLeafFile(leaf, app, obsidian), delay);
    };

    reserveUpdate();
    component.registerInterval(
        window.setInterval(reserveUpdate, 24 * 60 * 60 * 1000)
    );
}

/**
 * Get the settings of the core Daily Notes plugin.
 */
function getDailyNoteOptions(app) {
    const options = Object.assign(
        {},
        app.internalPlugins.plugins['daily-notes'].instance.options
    );
    options.format = options.format || 'YYYY-MM-DD';
    return options;
}

/**
 * Get today's daily note as TFile.
 */
async function getTodaysDailyNote(app, obsidian) {
    const { moment, normalizePath } = obsidian;
    const { folder, format } = getDailyNoteOptions(app);
    const path = normalizePath(`${folder}/${moment().format(format)}.md`);
    let file = app.vault.getAbstractFileByPath(path);
    if (!file) {
        // create it if it does not exist
        // !! It assumes that you use Templater’s folder template to generate a daily note. 
        // !! If not, it will create an empty note at the beginning of a day.
        file = await app.vault.create(path, '');
    }
    return file;
}

/**
 * Update the daily note opened in the leaf.
 */
async function updateLeafFile(leaf, app, obsidian) {
    // get today's daily note as TFile
    const file = await getTodaysDailyNote(app, obsidian)
    await leaf.openFile(file, { active: false });
}