add orderPreprocessors option

Author: matyunya

README.md

@@ -46,6 +46,10 @@ export default {
         }
       },
 
+      // Preprocessors will be applied in the order passed down to preprocess
+      // Default is (markup, then script, then style)
+      orderPreprocessors: false,
+
       // Emit CSS as "files" for other plugins to process
       emitCss: true,
 

index.js

@@ -31,6 +31,7 @@ const pluginOptions = {
 	extensions: true,
 	emitCss: true,
 	preprocess: true,
+	orderPreprocessors: true,
 
 	// legacy — we might want to remove/change these in a future version
 	onwarn: true,
@@ -219,22 +220,34 @@ module.exports = function svelte(options = {}) {
 									}
 									return resp;
 								}
-							);
+							)
 						};
 					}
-					preprocessPromise = preprocess(
-						code,
-						Object.assign(preprocessOptions, { filename: id })
-					).then(code => code.toString());
+						preprocessPromise = preprocess(
+							code,
+							Object.assign(preprocessOptions, { filename: id })
+						).then(code => code.toString());
 				} else {
-					preprocessPromise = preprocess(code, options.preprocess, {
-						filename: id
-					}).then(processed => {
-						if (processed.dependencies) {
-							dependencies.push(...processed.dependencies);
-						}
-						return processed.toString();
-					});
+					if (options.orderPreprocessors) {
+						preprocessPromise = options.preprocess.reduce((acc, cur) => {
+								 return Promise.resolve(acc).then(code => {
+									 return preprocess(
+										 code.code,
+										 cur,
+										 { filename: id }
+									)
+								 })
+							}, { code }).then(code => code.toString());
+					} else {
+						preprocessPromise = preprocess(code, options.preprocess, {
+							filename: id
+						}).then(processed => {
+							if (processed.dependencies) {
+								dependencies.push(...processed.dependencies);
+							}
+							return processed.toString();
+						});
+					}
 				}
 			} else {
 				preprocessPromise = Promise.resolve(code);