fix(core): remove global to avoid ambiguity in non-greedy match in fl…

…at mdx (#680)

.changeset/early-flies-glow.md

@@ -0,0 +1,5 @@
+---
+'@rspress/core': patch
+---
+
+fix(core): remove global to avoid ambiguity in non-greedy match in flat mdx

packages/core/src/node/constants.ts

@@ -4,7 +4,9 @@ import { RSPRESS_TEMP_DIR } from '@rspress/shared';
 
 export const isProduction = () => process.env.NODE_ENV === 'production';
 
-export const importStatementRegex = /import\s+(.*?)\s+from\s+['"](.*?)['"];?/gm;
+// Keep the quotation marks consistent before and after.
+export const importStatementRegex =
+  /import\s+(.*?)\s+from\s+(['"])(.*?)(?:"|');?/gm;
 
 // @ts-expect-error
 const dirname = path.dirname(fileURLToPath(new URL(import.meta.url)));

packages/core/src/node/utils/flattenMdxContent.ts

@@ -62,8 +62,12 @@ export async function flattenMdxContent(
   alias: Record<string, string | string[]>,
 ): Promise<string> {
   // Performance optimization: if the content does not contain any import statement, we can skip the parsing process
+  // So we need to check this match
 
-  if (!importStatementRegex.test(content)) {
+  // Create new regExp to avoid the regex cache the last match index
+  // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/test#using_test_on_a_regex_with_the_global_flag
+  const regex = new RegExp(importStatementRegex);
+  if (!regex.test(content)) {
     return content;
   }
   let result = content;