tiptap-markdown/src/util/markdown.js

Edit markdown content in tiptap editor.

import markdownit from 'markdown-it';

const md = markdownit();

function scanDelims(text, pos) {
    md.inline.State.prototype.scanDelims.call({ src: text, posMax: text.length })
    const state = new (md.inline.State)(text, null, null, []);
    return state.scanDelims(pos, true);
}

export function shiftDelim(text, delim, start, offset) {
    let res = text.substring(0, start) + text.substring(start + delim.length);
    res = res.substring(0, start + offset) + delim + res.substring(start + offset);
    return res;
}

function trimStart(text, delim, from, to) {
    let pos = from, res = text;
    while(pos < to) {
        if(scanDelims(res, pos).can_open) {
            break;
        }
        res = shiftDelim(res, delim, pos, 1);
        pos++;
    }
    return { text: res, from: pos, to }
}

function trimEnd(text, delim, from, to) {
    let pos = to, res = text;
    while(pos > from) {
        if(scanDelims(res, pos).can_close) {
            break;
        }
        res = shiftDelim(res, delim, pos, -1);
        pos--;
    }
    return { text: res, from, to: pos }
}

export function trimInline(text, delim, from, to) {
    let state = {
        text,
        from,
        to,
    }

    state = trimStart(state.text, delim, state.from, state.to);
    state = trimEnd(state.text, delim, state.from, state.to);

    if(state.to - state.from < delim.length + 1) {
        state.text = state.text.substring(0, state.from) + state.text.substring(state.to + delim.length);
    }

    return state.text;
}