SillyTavern/public/scripts/browser-fixes.js

const isFirefox = () => /firefox/i.test(navigator.userAgent);

function sanitizeInlineQuotationOnCopy() {
    // STRG+C, STRG+V on firefox leads to duplicate double quotes when inline quotation elements are copied.
    // To work around this, take the selection and transform <q> to <span> before calling toString().
    document.addEventListener('copy', function (event) {
        const selection = window.getSelection();
        if (selection.anchorNode.nodeName !== '#text' || selection.focusNode.nodeName !== '#text' || !selection.anchorNode?.parentElement.closest('.mes_text')) {
            // Complex selection, skip.
            return;
        }

        const range = selection.getRangeAt(0).cloneContents();
        const tempDOM = document.createDocumentFragment();

        function processNode(node) {
            if (node.nodeType === Node.ELEMENT_NODE && node.tagName.toLowerCase() === 'q') {
                // Transform <q> to <span>, preserve children
                const span = document.createElement('span');

                [...node.childNodes].forEach(child => {
                    const processedChild = processNode(child);
                    span.appendChild(processedChild);
                });

                return span;
            } else {
                // Nested structures containing <q> elements are unlikely
                return node.cloneNode(true);
            }
        }

        [...range.childNodes].forEach(child => {
            const processedChild = processNode(child);
            tempDOM.appendChild(processedChild);
        });

        const newRange = document.createRange();
        newRange.selectNodeContents(tempDOM);

        event.preventDefault();
        event.clipboardData.setData('text/plain', newRange.toString());
    });
}

function applyBrowserFixes() {
    if (isFirefox()) {
        sanitizeInlineQuotationOnCopy();
    }
}

export { isFirefox, applyBrowserFixes };