markdown-it-prism
Version:
Highlights code blocks in markdown-it using Prism.
304 lines (289 loc) • 15 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = markdownItPrism;
var _prismjs = _interopRequireDefault(require("prismjs"));
var _components = _interopRequireDefault(require("prismjs/components/"));
function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
function ownKeys(e, r) { var t = Object.keys(e); if (Object.getOwnPropertySymbols) { var o = Object.getOwnPropertySymbols(e); r && (o = o.filter(function (r) { return Object.getOwnPropertyDescriptor(e, r).enumerable; })), t.push.apply(t, o); } return t; }
function _objectSpread(e) { for (var r = 1; r < arguments.length; r++) { var t = null != arguments[r] ? arguments[r] : {}; r % 2 ? ownKeys(Object(t), !0).forEach(function (r) { _defineProperty(e, r, t[r]); }) : Object.getOwnPropertyDescriptors ? Object.defineProperties(e, Object.getOwnPropertyDescriptors(t)) : ownKeys(Object(t)).forEach(function (r) { Object.defineProperty(e, r, Object.getOwnPropertyDescriptor(t, r)); }); } return e; }
function _defineProperty(e, r, t) { return (r = _toPropertyKey(r)) in e ? Object.defineProperty(e, r, { value: t, enumerable: !0, configurable: !0, writable: !0 }) : e[r] = t, e; }
function _toPropertyKey(t) { var i = _toPrimitive(t, "string"); return "symbol" == typeof i ? i : i + ""; }
function _toPrimitive(t, r) { if ("object" != typeof t || !t) return t; var e = t[Symbol.toPrimitive]; if (void 0 !== e) { var i = e.call(t, r || "default"); if ("object" != typeof i) return i; throw new TypeError("@@toPrimitive must return a primitive value."); } return ("string" === r ? String : Number)(t); }
function _slicedToArray(r, e) { return _arrayWithHoles(r) || _iterableToArrayLimit(r, e) || _unsupportedIterableToArray(r, e) || _nonIterableRest(); }
function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); }
function _iterableToArrayLimit(r, l) { var t = null == r ? null : "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"]; if (null != t) { var e, n, i, u, a = [], f = !0, o = !1; try { if (i = (t = t.call(r)).next, 0 === l) { if (Object(t) !== t) return; f = !1; } else for (; !(f = (e = i.call(t)).done) && (a.push(e.value), a.length !== l); f = !0); } catch (r) { o = !0, n = r; } finally { try { if (!f && null != t.return && (u = t.return(), Object(u) !== u)) return; } finally { if (o) throw n; } } return a; } }
function _arrayWithHoles(r) { if (Array.isArray(r)) return r; }
function _createForOfIteratorHelper(r, e) { var t = "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"]; if (!t) { if (Array.isArray(r) || (t = _unsupportedIterableToArray(r)) || e && r && "number" == typeof r.length) { t && (r = t); var _n = 0, F = function F() {}; return { s: F, n: function n() { return _n >= r.length ? { done: !0 } : { done: !1, value: r[_n++] }; }, e: function e(r) { throw r; }, f: F }; } throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } var o, a = !0, u = !1; return { s: function s() { t = t.call(r); }, n: function n() { var r = t.next(); return a = r.done, r; }, e: function e(r) { u = !0, o = r; }, f: function f() { try { a || null == t.return || t.return(); } finally { if (u) throw o; } } }; }
function _unsupportedIterableToArray(r, a) { if (r) { if ("string" == typeof r) return _arrayLikeToArray(r, a); var t = {}.toString.call(r).slice(8, -1); return "Object" === t && r.constructor && (t = r.constructor.name), "Map" === t || "Set" === t ? Array.from(r) : "Arguments" === t || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(t) ? _arrayLikeToArray(r, a) : void 0; } }
function _arrayLikeToArray(r, a) { (null == a || a > r.length) && (a = r.length); for (var e = 0, n = Array(a); e < a; e++) n[e] = r[e]; return n; }
const SPECIFIED_LANGUAGE_META_KEY = 'de.joshuagleitze.markdown-it-prism.specifiedLanguage';
const DEFAULTS = {
highlightInlineCode: false,
plugins: [],
init: () => {
// do nothing by default
},
defaultLanguageForUnknown: undefined,
defaultLanguageForUnspecified: undefined,
defaultLanguage: undefined
};
/**
* Loads the provided `lang` into prism.
*
* @param lang
* Code of the language to load.
* @return The Prism language object for the provided {@code lang} code. {@code undefined} if the language is not known to Prism.
*/
function loadPrismLang(lang) {
if (!lang) return undefined;
let langObject = _prismjs.default.languages[lang];
if (langObject === undefined) {
(0, _components.default)([lang]);
langObject = _prismjs.default.languages[lang];
}
return langObject;
}
/**
* Loads the provided Prism plugin.
* @param name
* Name of the plugin to load.
* @throws {Error} If there is no plugin with the provided `name`.
*/
function loadPrismPlugin(name) {
try {
// eslint-disable-next-line @typescript-eslint/no-require-imports
require(`prismjs/plugins/${name}/prism-${name}`);
} catch (cause) {
throw new Error(`Cannot load Prism plugin "${name}". Please check the spelling.`, {
cause
});
}
}
/**
* Select the language to use for highlighting, based on the provided options and the specified language.
*
* @param options
* The options that were used to initialise the plugin.
* @param lang
* Code of the language to highlight the text in.
* @return The name of the language to use and the Prism language object for that language.
*/
function selectLanguage(options, lang) {
let langToUse = lang;
if (langToUse === '' && options.defaultLanguageForUnspecified !== undefined) {
langToUse = options.defaultLanguageForUnspecified;
}
let prismLang = loadPrismLang(langToUse);
if (prismLang === undefined && options.defaultLanguageForUnknown !== undefined) {
langToUse = options.defaultLanguageForUnknown;
prismLang = loadPrismLang(langToUse);
}
return [langToUse, prismLang];
}
/**
* Highlights the provided text using Prism.
*
* @param markdownit
* The markdown-it instance.
* @param options
* The options that have been used to initialise the plugin.
* @param text
* The text to highlight.
* @param lang
* Code of the language to highlight the text in.
* @return If Prism knows the language that {@link selectLanguage} returns for `lang`, the `text` highlighted for that language. Otherwise, `text`
* html-escaped.
*/
function highlight(markdownit, options, text, lang) {
return highlightWithSelectedLanguage(markdownit, options, text, selectLanguage(options, lang));
}
/**
* Highlights the provided text using Prism.
*
* @param markdownit
* The markdown-it instance.
* @param options
* The options that have been used to initialise the plugin.
* @param text
* The text to highlight.
* @param lang
* The selected Prism language to use for highlighting.
* @return If Prism knows the language that {@link selectLanguage} returns for `lang`, the `text` highlighted for that language. Otherwise, `text`
* html-escaped.
*/
function highlightWithSelectedLanguage(markdownit, options, text, [langToUse, prismLang]) {
return prismLang ? _prismjs.default.highlight(text, prismLang, langToUse) : markdownit.utils.escapeHtml(text);
}
/**
* Construct the class name for the provided `lang`.
*
* @param markdownit
* The markdown-it instance.
* @param lang
* The selected language.
* @return the class to use for `lang`.
*/
function languageClass(markdownit, lang) {
return markdownit.options.langPrefix + lang;
}
/**
* A {@link RuleCore} that searches for and extracts language specifications on inline code tokens.
*/
function inlineCodeLanguageRule(state) {
var _iterator = _createForOfIteratorHelper(state.tokens),
_step;
try {
for (_iterator.s(); !(_step = _iterator.n()).done;) {
const inlineToken = _step.value;
if (inlineToken.type === 'inline' && inlineToken.children !== null) {
var _iterator2 = _createForOfIteratorHelper(inlineToken.children.entries()),
_step2;
try {
for (_iterator2.s(); !(_step2 = _iterator2.n()).done;) {
const _step2$value = _slicedToArray(_step2.value, 2),
index = _step2$value[0],
token = _step2$value[1];
if (token.type === 'code_inline' && index + 1 < inlineToken.children.length) {
extractInlineCodeSpecifiedLanguage(token, inlineToken.children[index + 1]);
}
}
} catch (err) {
_iterator2.e(err);
} finally {
_iterator2.f();
}
}
}
} catch (err) {
_iterator.e(err);
} finally {
_iterator.f();
}
}
/**
* Searches for a language specification after an inline code token (e.g. ``{language=cpp}). If present, extracts the language, sets
* it on `inlineCodeToken`’s meta, and removes the specification.
*
* @param inlineCodeToken
* The inline code token for which to extract the language.
* @param followingToken
* The token immediately following the `inlineCodeToken`.
*/
function extractInlineCodeSpecifiedLanguage(inlineCodeToken, followingToken) {
const languageSpecificationMatch = followingToken.content.match(/^\{((?:[^\s}]+\s)*)language=([^\s}]+)((?:\s[^\s}]+)*)}/);
if (languageSpecificationMatch !== null) {
inlineCodeToken.meta = _objectSpread(_objectSpread({}, inlineCodeToken.meta), {}, {
[SPECIFIED_LANGUAGE_META_KEY]: languageSpecificationMatch[2]
});
followingToken.content = followingToken.content.slice(languageSpecificationMatch[0].length);
if (languageSpecificationMatch[1] || languageSpecificationMatch[3]) {
followingToken.content = `{${languageSpecificationMatch[1] || ''}${(languageSpecificationMatch[3] || ' ').slice(1)}}${followingToken.content}`;
}
}
}
/**
* Patch the `<pre>` and `<code>` tags produced by the `existingRule` for fenced code blocks.
*
* @param markdownit
* The markdown-it instance.
* @param options
* The options that have been used to initialise the plugin.
* @param existingRule
* The previously configured render rule for fenced code blocks.
*/
function applyCodeAttributes(markdownit, options, existingRule) {
return (tokens, idx, renderOptions, env, self) => {
const fenceToken = tokens[idx];
const info = fenceToken.info ? markdownit.utils.unescapeAll(fenceToken.info).trim() : '';
const lang = info.split(/(\s+)/g)[0];
const _selectLanguage = selectLanguage(options, lang),
_selectLanguage2 = _slicedToArray(_selectLanguage, 1),
langToUse = _selectLanguage2[0];
if (!langToUse) {
return existingRule(tokens, idx, renderOptions, env, self);
} else {
fenceToken.info = langToUse;
const existingResult = existingRule(tokens, idx, renderOptions, env, self);
const langClass = languageClass(markdownit, markdownit.utils.escapeHtml(langToUse));
return existingResult.replace(/<((?:pre|code)[^>]*?)(?:\s+class="([^"]*)"([^>]*))?>/g, (match, tagStart, existingClasses, tagEnd) => existingClasses !== null && existingClasses !== void 0 && existingClasses.includes(langClass) ? match : `<${tagStart} class="${existingClasses ? `${existingClasses} ` : ''}${langClass}"${tagEnd || ''}>`);
}
};
}
/**
* Renders inline code tokens by highlighting them with Prism.
*
* @param markdownit
* The markdown-it instance.
* @param options
* The options that have been used to initialise the plugin.
* @param existingRule
* The previously configured render rule for inline code.
*/
function renderInlineCode(markdownit, options, existingRule) {
return (tokens, idx, renderOptions, env, self) => {
const inlineCodeToken = tokens[idx];
const specifiedLanguage = inlineCodeToken.meta ? inlineCodeToken.meta[SPECIFIED_LANGUAGE_META_KEY] || '' : '';
const _selectLanguage3 = selectLanguage(options, specifiedLanguage),
_selectLanguage4 = _slicedToArray(_selectLanguage3, 2),
langToUse = _selectLanguage4[0],
prismLang = _selectLanguage4[1];
if (!langToUse) {
return existingRule(tokens, idx, renderOptions, env, self);
} else {
const highlighted = highlightWithSelectedLanguage(markdownit, options, inlineCodeToken.content, [langToUse, prismLang]);
inlineCodeToken.attrJoin('class', languageClass(markdownit, langToUse));
return `<code${self.renderAttrs(inlineCodeToken)}>${highlighted}</code>`;
}
};
}
/**
* Checks whether an option represents a valid Prism language
*
* @param options
* The options that have been used to initialise the plugin.
* @param optionName
* The key of the option inside {@code options} that shall be checked.
* @throws {Error} If the option is not set to a valid Prism language.
*/
function checkLanguageOption(options, optionName) {
const language = options[optionName];
if (language !== undefined && loadPrismLang(language) === undefined) {
throw new Error(`Bad option ${optionName}: There is no Prism language '${language}'.`);
}
}
/**
* ‘the most basic rule to render a token’ (https://github.com/markdown-it/markdown-it/blob/master/docs/examples/renderer_rules.md)
*/
function renderFallback(tokens, idx, options, env, self) {
return self.renderToken(tokens, idx, options);
}
/**
* Initialisation function of the plugin. This function is not called directly by clients, but is rather provided
* to MarkdownIt’s {@link MarkdownIt.use} function.
*
* @param markdownit
* The markdown it instance the plugin is being registered to.
* @param useroptions
* The options this plugin is being initialised with.
*/
function markdownItPrism(markdownit, useroptions) {
const options = Object.assign({}, DEFAULTS, useroptions);
checkLanguageOption(options, 'defaultLanguage');
checkLanguageOption(options, 'defaultLanguageForUnknown');
checkLanguageOption(options, 'defaultLanguageForUnspecified');
options.defaultLanguageForUnknown = options.defaultLanguageForUnknown || options.defaultLanguage;
options.defaultLanguageForUnspecified = options.defaultLanguageForUnspecified || options.defaultLanguage;
options.plugins.forEach(loadPrismPlugin);
options.init(_prismjs.default);
// register ourselves as highlighter
markdownit.options.highlight = (text, lang) => highlight(markdownit, options, text, lang);
markdownit.renderer.rules.fence = applyCodeAttributes(markdownit, options, markdownit.renderer.rules.fence || renderFallback);
if (options.highlightInlineCode) {
markdownit.core.ruler.after('inline', 'prism_inline_code_language', inlineCodeLanguageRule);
markdownit.renderer.rules.code_inline = renderInlineCode(markdownit, options, markdownit.renderer.rules.code_inline || renderFallback);
}
}
module.exports = exports.default;
module.exports.default = exports.default;