WIP: Improve TypeScript imports preprocessing (#318)

package.json

@@ -93,6 +93,8 @@
     "@types/pug": "^2.0.4",
     "@types/sass": "^1.16.0",
     "detect-indent": "^6.0.0",
+    "magic-string": "^0.25.7",
+    "sorcery": "^0.10.0",
     "strip-indent": "^3.0.0"
   },
   "peerDependencies": {

src/autoProcess.ts

@@ -60,7 +60,7 @@ type AutoPreprocessOptions = {
 export const transform = async (
   name: string,
   options: TransformerOptions,
-  { content, map, filename, attributes }: TransformerArgs<any>,
+  { content, markup, map, filename, attributes }: TransformerArgs<any>,
 ): Promise<Processed> => {
   if (options === false) {
     return { code: content };
@@ -75,6 +75,7 @@ export const transform = async (
 
   return transformer({
     content,
+    markup,
     filename,
     map,
     attributes,
@@ -151,6 +152,7 @@ export function sveltePreprocess(
   ): Preprocessor => async (svelteFile) => {
     let {
       content,
+      markup,
       filename,
       lang,
       alias,
@@ -187,6 +189,7 @@ export function sveltePreprocess(
 
     const transformed = await transform(lang, transformerOptions, {
       content,
+      markup,
       filename,
       attributes,
     });
@@ -205,6 +208,7 @@ export function sveltePreprocess(
     if (transformers.replace) {
       const transformed = await transform('replace', transformers.replace, {
         content,
+        markup: content,
         filename,
       });
 
@@ -221,11 +225,13 @@ export function sveltePreprocess(
   const script: PreprocessorGroup['script'] = async ({
     content,
     attributes,
+    markup: fullMarkup,
     filename,
   }) => {
     const transformResult: Processed = await scriptTransformer({
       content,
       attributes,
+      markup: fullMarkup,
       filename,
     });
 
@@ -235,7 +241,7 @@ export function sveltePreprocess(
       const transformed = await transform(
         'babel',
         getTransformerOptions('babel'),
-        { content: code, map, filename, attributes },
+        { content: code, markup: fullMarkup, map, filename, attributes },
       );
 
       code = transformed.code;
@@ -250,11 +256,13 @@ export function sveltePreprocess(
   const style: PreprocessorGroup['style'] = async ({
     content,
     attributes,
+    markup: fullMarkup,
     filename,
   }) => {
     const transformResult = await cssTransformer({
       content,
       attributes,
+      markup: fullMarkup,
       filename,
     });
 
@@ -275,6 +283,7 @@ export function sveltePreprocess(
 
         const transformed = await transform('postcss', postcssOptions, {
           content: code,
+          markup: fullMarkup,
           map,
           filename,
           attributes,
@@ -288,7 +297,7 @@ export function sveltePreprocess(
       const transformed = await transform(
         'globalStyle',
         getTransformerOptions('globalStyle'),
-        { content: code, map, filename, attributes },
+        { content: code, markup: fullMarkup, map, filename, attributes },
       );
 
       code = transformed.code;

src/modules/markup.ts

@@ -1,5 +1,35 @@
 import type { Transformer, Preprocessor } from '../types';
 
+/** Create a tag matching regexp. */
+export function createTagRegex(tagName: string, flags?: string): RegExp {
+  return new RegExp(
+    `<!--[^]*?-->|<${tagName}(\\s[^]*?)?(?:>([^]*?)<\\/${tagName}>|\\/>)`,
+    flags,
+  );
+}
+
+/** Strip script and style tags from markup. */
+export function stripTags(markup: string): string {
+  return markup
+    .replace(createTagRegex('style', 'gi'), '')
+    .replace(createTagRegex('script', 'gi'), '');
+}
+
+/** Transform an attribute string into a key-value object */
+export function parseAttributes(attributesStr: string): Record<string, any> {
+  return attributesStr
+    .split(/\s+/)
+    .filter(Boolean)
+    .reduce((acc: Record<string, string | boolean>, attr) => {
+      const [name, value] = attr.split('=');
+
+      // istanbul ignore next
+      acc[name] = value ? value.replace(/['"]/g, '') : true;
+
+      return acc;
+    }, {});
+}
+
 export async function transformMarkup(
   { content, filename }: { content: string; filename: string },
   transformer: Preprocessor | Transformer<unknown>,
@@ -9,35 +39,29 @@ export async function transformMarkup(
 
   markupTagName = markupTagName.toLocaleLowerCase();
 
-  const markupPattern = new RegExp(
-    `/<!--[^]*?-->|<${markupTagName}(\\s[^]*?)?(?:>([^]*?)<\\/${markupTagName}>|\\/>)`,
-  );
+  const markupPattern = createTagRegex(markupTagName);
 
   const templateMatch = content.match(markupPattern);
 
   /** If no <template> was found, run the transformer over the whole thing */
   if (!templateMatch) {
-    return transformer({ content, attributes: {}, filename, options });
+    return transformer({
+      content,
+      markup: content,
+      attributes: {},
+      filename,
+      options,
+    });
   }
 
   const [fullMatch, attributesStr = '', templateCode] = templateMatch;
 
-  /** Transform an attribute string into a key-value object */
-  const attributes = attributesStr
-    .split(/\s+/)
-    .filter(Boolean)
-    .reduce((acc: Record<string, string | boolean>, attr) => {
-      const [name, value] = attr.split('=');
-
-      // istanbul ignore next
-      acc[name] = value ? value.replace(/['"]/g, '') : true;
-
-      return acc;
-    }, {});
+  const attributes = parseAttributes(attributesStr);
 
   /** Transform the found template code */
   let { code, map, dependencies } = await transformer({
     content: templateCode,
+    markup: templateCode,
     attributes,
     filename,
     options,

src/modules/tagInfo.ts

@@ -27,6 +27,7 @@ export const getTagInfo = async ({
   attributes,
   filename,
   content,
+  markup,
 }: PreprocessorArgs) => {
   const dependencies = [];
   // catches empty content and self-closing tags
@@ -62,5 +63,6 @@ export const getTagInfo = async ({
     lang,
     alias,
     dependencies,
+    markup,
   };
 };

src/processors/typescript.ts

@@ -8,6 +8,7 @@ export default (options?: Options.Typescript): PreprocessorGroup => ({
     const { transformer } = await import('../transformers/typescript');
     let {
       content,
+      markup,
       filename,
       attributes,
       lang,
@@ -22,6 +23,7 @@ export default (options?: Options.Typescript): PreprocessorGroup => ({
 
     const transformed = await transformer({
       content,
+      markup,
       filename,
       attributes,
       options,