firefox-main/browser/components/aiwindow/ui/modules/ChatMarkdownParser.mjs (file symbol)

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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* Markdown parser for Smart Window chat messages.
*/
import { MarkdownIt } from "chrome://browser/content/multilineeditor/prosemirror.bundle.mjs";
export const CHAT_WRAPPER_ELEMENTS = {
table: {
element: "ai-chat-table",
attributes: ["message-id", "data-line-range"],
},
};
// Create with default preset for markdown parsing similar to GFM. Among other
// things this enables us to render tables.
const md = MarkdownIt("default", { html: false });
// Add element wrapper rules.
for (const [element, { element: wrapper }] of Object.entries(
CHAT_WRAPPER_ELEMENTS
)) {
md.renderer.rules[`${element}_open`] = (
tokens,
index,
options,
_env,
renderer
) => {
const dataAttributes = new Map();
if (element === "table") {
const { map } = tokens[index];
if (map) {
dataAttributes.set("data-line-range", JSON.stringify(map));
}
}
const attributesString = [...dataAttributes]
.map(([key, value]) => `${key}="${md.utils.escapeHtml(value)}"`)
.join(" ");
return `<${wrapper}${attributesString ? ` ${attributesString}` : ""}>${renderer.renderToken(tokens, index, options)}`;
};
md.renderer.rules[`${element}_close`] = (
tokens,
index,
options,
_env,
renderer
) => `${renderer.renderToken(tokens, index, options)}</${wrapper}>`;
}
// A link the model invented has nowhere to point once its hallucinated URL
// token is stripped from the message, leaving `[label]()`. Markdown reads that
// as a link with an empty destination and renders an anchor that goes nowhere,
// so drop the anchor and keep the label as plain text.
function hasDestination(token) {
return Boolean(token?.attrGet("href")?.trim());
}
md.renderer.rules.link_open = (tokens, index, options, _env, renderer) =>
hasDestination(tokens[index])
? renderer.renderToken(tokens, index, options)
: "";
md.renderer.rules.link_close = (tokens, index, options, _env, renderer) => {
// Markdown links can't nest, so the nearest preceding `link_open` is the
// one this token closes.
let lastOpenLinkToken = null;
for (let i = index - 1; i >= 0; i--) {
if (tokens[i].type === "link_open") {
lastOpenLinkToken = tokens[i];
break;
}
}
return lastOpenLinkToken && !hasDestination(lastOpenLinkToken)
? ""
: renderer.renderToken(tokens, index, options);
};
/**
* Parse markdown to HTML.
*
* @param {string} markdown - The markdown string to parse
* @returns {string} HTML string
*/
export function parseMarkdown(markdown) {
return md.render(markdown);
}
/**
* Parse markdown into an ordered list of top-level blocks, each
* rendered to its own HTML string. Joining every block's html is identical
* to parseMarkdown(markdown); splitting this way lets a streamed reply re-render
* only the blocks that changed.
*
* @param {string} markdown - The markdown string to parse
* @returns {Array<{html: string}>} One entry per top-level block, in order
*/
export function parseMarkdownBlocks(markdown) {
const env = {};
const tokens = md.parse(markdown, env);
const blocks = [];
let start = 0;
while (start < tokens.length) {
let end = start + 1;
if (tokens[start].nesting === 1) {
// Walk to the matching close: the nesting counts sum back to zero there.
let depth = 1;
while (end < tokens.length && depth > 0) {
depth += tokens[end].nesting;
end++;
}
}
blocks.push({
html: md.renderer.render(tokens.slice(start, end), md.options, env),
});
start = end;
}
return blocks;
}