Make dynamic imports relative to the importing script

src/rewrite/index.js

@@ -51,6 +51,7 @@ class Ultraviolet {
         //this.urlRegex = /^(#|about:|data:|mailto:|javascript:)/;
         this.urlRegex = /^(#|about:|data:|mailto:)/;
         this.rewriteUrl = options.rewriteUrl || this.rewriteUrl;
+        this.rewriteImport = options.rewriteImport || this.rewriteImport;
         this.sourceUrl = options.sourceUrl || this.sourceUrl;
         this.encodeUrl = options.encodeUrl || this.encodeUrl;
         this.decodeUrl = options.decodeUrl || this.decodeUrl;
@@ -97,6 +98,19 @@ class Ultraviolet {
             setCookie,
         };
     }
+    /**
+     *
+     * @param {string} str Script being imported
+     * @param {string} src Script that is importing
+     * @param {*} meta
+     */
+    rewriteImport(str, src, meta = this.meta) {
+        // use importiing script as the base
+        return this.rewriteUrl(str, {
+            ...meta,
+            base: src,
+        });
+    }
     rewriteUrl(str, meta = this.meta) {
         str = new String(str).trim();
         if (!str || this.urlRegex.test(str)) return str;

src/rewrite/rewrite.script.js

@@ -263,7 +263,9 @@ function dynamicImport(ctx) {
     js.on(Syntax.ImportExpression, (node, data, type) => {
         if (type !== 'rewrite') return false;
         data.changes.push({
-            node: '__uv.rewriteUrl(',
+            // pass script URL to dynamicImport
+            // import() is always relative to script URL
+            node: `__uv.rewriteImport(${JSON.stringify(ctx.meta.url)},`,
             start: node.source.start,
             end: node.source.start,
         });