add initial marp implementation with sample content and build configuration

node_modules/@marp-team/marpit/lib/postcss/import/replace.js

@@ -0,0 +1,48 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.importReplace = exports.default = void 0;
+var _postcss_plugin = _interopRequireDefault(require("../../helpers/postcss_plugin"));
+var _parse = _interopRequireDefault(require("./parse"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+/** @module */
+
+/**
+ * Marpit PostCSS import replace plugin.
+ *
+ * Replace parsed `@import` / `@import-theme` rules.
+ *
+ * Please see {@link module:postcss/import/parse} about the specification of
+ * each syntax.
+ *
+ * @function importReplace
+ * @param {ThemeSet} themeSet ThemeSet instance.
+ */
+const importReplace = (themeSet, importedThemes = []) => (0, _postcss_plugin.default)('marpit-postcss-import-replace', () => ({
+  plugins: [(0, _parse.default)(), (0, _postcss_plugin.default)('marpit-postcss-import-replace-processor', () => (css, {
+    postcss
+  }) => {
+    const prepends = [];
+    css.walk(node => {
+      const name = node.marpitImportParse;
+      if (name) {
+        const theme = themeSet.get(name);
+        if (theme) {
+          if (importedThemes.includes(name)) throw new Error(`Circular "${name}" theme import is detected.`);
+          const processed = postcss([importReplace(themeSet, [...importedThemes, name])]).process(theme.css);
+          if (node.name === 'import') {
+            node.replaceWith(processed.root);
+          } else {
+            node.remove();
+            prepends.unshift(processed.root);
+          }
+        }
+      }
+    });
+    for (const root of prepends) css.first.before(root);
+  })()]
+}));
+exports.importReplace = importReplace;
+var _default = exports.default = importReplace;