104 lines
3.6 KiB
TypeScript
104 lines
3.6 KiB
TypeScript
import type * as shiki from 'shiki';
|
|
import { getHighlighter } from 'shiki';
|
|
import { visit } from 'unist-util-visit';
|
|
import type { RemarkPlugin, ShikiConfig } from './types.js';
|
|
|
|
/**
|
|
* getHighlighter() is the most expensive step of Shiki. Instead of calling it on every page,
|
|
* cache it here as much as possible. Make sure that your highlighters can be cached, state-free.
|
|
* We make this async, so that multiple calls to parse markdown still share the same highlighter.
|
|
*/
|
|
const highlighterCacheAsync = new Map<string, Promise<shiki.Highlighter>>();
|
|
|
|
export function remarkShiki({
|
|
langs = [],
|
|
theme = 'github-dark',
|
|
wrap = false,
|
|
}: ShikiConfig = {}): ReturnType<RemarkPlugin> {
|
|
const cacheID: string = typeof theme === 'string' ? theme : theme.name;
|
|
let highlighterAsync = highlighterCacheAsync.get(cacheID);
|
|
if (!highlighterAsync) {
|
|
highlighterAsync = getHighlighter({ theme }).then((hl) => {
|
|
hl.setColorReplacements({
|
|
'#000001': 'var(--astro-code-color-text)',
|
|
'#000002': 'var(--astro-code-color-background)',
|
|
'#000004': 'var(--astro-code-token-constant)',
|
|
'#000005': 'var(--astro-code-token-string)',
|
|
'#000006': 'var(--astro-code-token-comment)',
|
|
'#000007': 'var(--astro-code-token-keyword)',
|
|
'#000008': 'var(--astro-code-token-parameter)',
|
|
'#000009': 'var(--astro-code-token-function)',
|
|
'#000010': 'var(--astro-code-token-string-expression)',
|
|
'#000011': 'var(--astro-code-token-punctuation)',
|
|
'#000012': 'var(--astro-code-token-link)',
|
|
});
|
|
return hl;
|
|
});
|
|
highlighterCacheAsync.set(cacheID, highlighterAsync);
|
|
}
|
|
|
|
let highlighter: shiki.Highlighter;
|
|
|
|
return async (tree: any) => {
|
|
// Lazily assign the highlighter as async can only happen within this function,
|
|
// and not on `remarkShiki` directly.
|
|
if (!highlighter) {
|
|
highlighter = await highlighterAsync!;
|
|
|
|
// NOTE: There may be a performance issue here for large sites that use `lang`.
|
|
// Since this will be called on every page load. Unclear how to fix this.
|
|
for (const lang of langs) {
|
|
await highlighter.loadLanguage(lang);
|
|
}
|
|
}
|
|
|
|
visit(tree, 'code', (node) => {
|
|
let lang: string;
|
|
|
|
if (typeof node.lang === 'string') {
|
|
const langExists = highlighter.getLoadedLanguages().includes(node.lang);
|
|
if (langExists) {
|
|
lang = node.lang;
|
|
} else {
|
|
// eslint-disable-next-line no-console
|
|
console.warn(`The language "${node.lang}" doesn't exist, falling back to plaintext.`);
|
|
lang = 'plaintext';
|
|
}
|
|
} else {
|
|
lang = 'plaintext';
|
|
}
|
|
|
|
let html = highlighter.codeToHtml(node.value, { lang });
|
|
|
|
// Q: Couldn't these regexes match on a user's inputted code blocks?
|
|
// A: Nope! All rendered HTML is properly escaped.
|
|
// Ex. If a user typed `<span class="line"` into a code block,
|
|
// It would become this before hitting our regexes:
|
|
// <span class="line"
|
|
|
|
// Replace "shiki" class naming with "astro" and add "is:raw".
|
|
html = html.replace(/<pre class="(.*?)shiki(.*?)"/, `<pre is:raw class="$1astro-code$2"`);
|
|
// Add "user-select: none;" for "+"/"-" diff symbols
|
|
if (node.lang === 'diff') {
|
|
html = html.replace(
|
|
/<span class="line"><span style="(.*?)">([\+|\-])/g,
|
|
'<span class="line"><span style="$1"><span style="user-select: none;">$2</span>'
|
|
);
|
|
}
|
|
// Handle code wrapping
|
|
// if wrap=null, do nothing.
|
|
if (wrap === false) {
|
|
html = html.replace(/style="(.*?)"/, 'style="$1; overflow-x: auto;"');
|
|
} else if (wrap === true) {
|
|
html = html.replace(
|
|
/style="(.*?)"/,
|
|
'style="$1; overflow-x: auto; white-space: pre-wrap; word-wrap: break-word;"'
|
|
);
|
|
}
|
|
|
|
node.type = 'html';
|
|
node.value = html;
|
|
node.children = [];
|
|
});
|
|
};
|
|
}
|