work.suroh.tk/node_modules/gray-matter/lib/stringify.js

57 lines
1.4 KiB
JavaScript

'use strict';
const typeOf = require('kind-of');
const getEngine = require('./engine');
const defaults = require('./defaults');
module.exports = function(file, data, options) {
if (data == null && options == null) {
switch (typeOf(file)) {
case 'object':
data = file.data;
options = {};
break;
case 'string':
return file;
default: {
throw new TypeError('expected file to be a string or object');
}
}
}
const str = file.content;
const opts = defaults(options);
if (data == null) {
if (!opts.data) return file;
data = opts.data;
}
const language = file.language || opts.language;
const engine = getEngine(language, opts);
if (typeof engine.stringify !== 'function') {
throw new TypeError('expected "' + language + '.stringify" to be a function');
}
data = Object.assign({}, file.data, data);
const open = opts.delimiters[0];
const close = opts.delimiters[1];
const matter = engine.stringify(data, options).trim();
let buf = '';
if (matter !== '{}') {
buf = newline(open) + newline(matter) + newline(close);
}
if (typeof file.excerpt === 'string' && file.excerpt !== '') {
if (str.indexOf(file.excerpt.trim()) === -1) {
buf += newline(file.excerpt) + newline(close);
}
}
return buf + newline(str);
};
function newline(str) {
return str.slice(-1) !== '\n' ? str + '\n' : str;
}