Convert to ES modules and related changes

src/frontmatter.js

@@ -0,0 +1,81 @@
+import * as luxon from 'luxon';
+
+import * as settings from './settings.js';
+
+// get author, without decoding
+// WordPress doesn't allow funky characters in usernames anyway
+export function getAuthor(post) {
+	return post.data.creator[0];
+}
+
+// get array of decoded category names, filtered as specified in settings
+export function getCategories(post) {
+    if (!post.data.category) {
+        return [];
+    }
+
+    const categories = post.data.category
+        .filter(category => category.$.domain === 'category')
+        .map(({ $: attributes }) => decodeURIComponent(attributes.nicename));
+
+    return categories.filter(category => !settings.filter_categories.includes(category));
+}
+
+// get cover image filename, previously decoded and set on post.meta
+// this one is unique as it relies on special logic executed by the parser
+export function getCoverImage(post) {
+	return post.meta.coverImage;
+}
+
+// get post date, optionally formatted as specified in settings
+// this value is also used for year/month folders, date prefixes, etc. as needed
+export function getDate(post) {
+    const dateTime = luxon.DateTime.fromRFC2822(post.data.pubDate[0], { zone: settings.custom_date_timezone });
+
+    if (settings.custom_date_formatting) {
+        return dateTime.toFormat(settings.custom_date_formatting);
+    } else if (settings.include_time_with_date) {
+        return dateTime.toISO();
+    } else {
+        return dateTime.toISODate();
+    }
+}
+
+// get excerpt, not decoded, newlines collapsed
+export function getExcerpt(post) {
+	return post.data.encoded[1].replace(/[\r\n]+/gm, ' ');
+}
+
+// get ID
+export function getId(post) {
+	return post.data.post_id[0];
+}
+
+// get slug, previously decoded and set on post.meta
+export function getSlug(post) {
+	return post.meta.slug;
+}
+
+// get array of decoded tag names
+export function getTags(post) {
+	if (!post.data.category) {
+		return [];
+	}
+
+	const categories = post.data.category
+		.filter(category => category.$.domain === 'post_tag')
+		.map(({ $: attributes }) => decodeURIComponent(attributes.nicename));
+
+	return categories;
+}
+
+// get simple post title, but not decoded like other frontmatter string fields
+export function getTitle(post) {
+	return post.data.title[0];
+}
+
+// get type, often this will always be "post"
+// but can also be "page" or other custom types
+export function getType(post) {
+	return post.data.post_type[0];
+}