Fix: Quote non-identifier export names in ESM library output

crates/rspack_plugin_library/src/modern_module_library_plugin.rs

@@ -6,7 +6,7 @@
   CompilationOptimizeChunkModules, CompilationParams, CompilerCompilation, CompilerFinishMake,
   ConcatenatedModule, ConcatenatedModuleExportsDefinitions, DependencyId, ExportsType,
   LibraryOptions, ModuleGraph, ModuleIdentifier, Plugin, PrefetchExportsInfoMode, RuntimeSpec,
-  RuntimeVariable, UsedNameItem,
+  RuntimeVariable, UsedNameItem, export_name,
   rspack_sources::{ConcatSource, RawStringSource, SourceExt},
   to_identifier,
 };
@@ -397,7 +397,10 @@
       })
       .map(|(local, exported)| {
         if let Some(exported) = exported {
-          format!("{local} as {exported}")
+          // Use export_name to properly quote identifiers that aren't valid JavaScript identifiers
+          let quoted_exported = export_name(exported)
+            .unwrap_or_else(|_| panic!("Failed to generate valid export name for: {}", exported));
+          format!("{local} as {quoted_exported}")
         } else {
           local.clone()
         }

tests/rspack-test/configCases/library/modern-module-json-special-chars/data.json

@@ -0,0 +1,6 @@
+{
+  "!top": "exclamation",
+  "regular": "normal",
+  "a.b": "dot",
+  "a-b": "dash"
+}

tests/rspack-test/configCases/library/modern-module-json-special-chars/index.js

@@ -0,0 +1,21 @@
+import fs from 'fs'
+import path from 'path'
+
+it('should properly quote export names that are not valid identifiers', async () => {
+const json = fs.readFileSync(path.resolve(import.meta.dirname, './json.mjs'), 'utf-8');
+
+// The export statement should quote special identifiers
+expect(json).toContain('"!top"');
+expect(json).toContain('"a.b"');
+expect(json).toContain('"a-b"');
+
+// Should not contain unquoted special chars which would be syntax errors
+expect(json).not.toMatch(/\bas !top\b/);
+expect(json).not.toMatch(/\bas a\.b\b/);
+
+const jsonModule = await import(/*webpackIgnore: true*/'./json.mjs');
+expect(jsonModule["!top"]).toBe("exclamation");
+expect(jsonModule["regular"]).toBe("normal");
+expect(jsonModule["a.b"]).toBe("dot");
+expect(jsonModule["a-b"]).toBe("dash");
+})

tests/rspack-test/configCases/library/modern-module-json-special-chars/rspack.config.js

@@ -0,0 +1,19 @@
+module.exports = {
+entry: {
+main: {import: './index.js', filename: 'bundle.mjs'},
+json: {import: './data.json', filename: 'json.mjs'},
+},
+output: {
+module: true,
+library: {
+type: 'modern-module',
+},
+},
+module: {
+parser: {
+javascript: {
+importMeta: false
+}
+}
+},
+}

tests/rspack-test/configCases/library/modern-module-json-special-chars/test.config.js

@@ -0,0 +1,5 @@
+module.exports = {
+experiments: {
+outputModule: true,
+},
+}