Improve barrel optimizer with loader caching and wilcard exports

packages/next-swc/crates/core/src/lib.rs

@@ -258,9 +258,8 @@ where
             None => Either::Right(noop()),
         },
         match &opts.optimize_barrel_exports {
-            Some(config) => Either::Left(optimize_barrel::optimize_barrel(
-                file.name.clone(),config.clone())),
-            None => Either::Right(noop()),
+            Some(config) => Either::Left(optimize_barrel::optimize_barrel(config.clone())),
+            _ => Either::Right(noop()),
         },
         opts.emotion
             .as_ref()

packages/next-swc/crates/core/src/named_import_transform.rs

@@ -61,10 +61,7 @@ impl Fold for NamedImportTransform {
 
             if !skip_transform {
                 let names = specifier_names.join(",");
-                let new_src = format!(
-                    "__barrel_optimize__?names={}!=!{}?__barrel_optimize_noop__={}",
-                    names, src_value, names,
-                );
+                let new_src = format!("__barrel_optimize__?names={}!=!{}", names, src_value);
 
                 // Create a new import declaration, keep everything the same except the source
                 let mut new_decl = decl.clone();

packages/next-swc/crates/core/tests/fixture.rs

@@ -482,7 +482,7 @@ fn named_import_transform_fixture(input: PathBuf) {
     );
 }
 
-#[fixture("tests/fixture/optimize-barrel/**/input.js")]
+#[fixture("tests/fixture/optimize-barrel/normal/**/input.js")]
 fn optimize_barrel_fixture(input: PathBuf) {
     let output = input.parent().unwrap().join("output.js");
     test_fixture(
@@ -493,16 +493,39 @@ fn optimize_barrel_fixture(input: PathBuf) {
 
             chain!(
                 resolver(unresolved_mark, top_level_mark, false),
-                optimize_barrel(
-                    FileName::Real(PathBuf::from("/some-project/node_modules/foo/file.js")),
-                    json(
-                        r#"
+                optimize_barrel(json(
+                    r#"
                         {
-                            "names": ["x", "y", "z"]
+                            "wildcard": false
                         }
-                        "#
-                    )
-                )
+                    "#
+                ))
+            )
+        },
+        &input,
+        &output,
+        Default::default(),
+    );
+}
+
+#[fixture("tests/fixture/optimize-barrel/wildcard/**/input.js")]
+fn optimize_barrel_wildcard_fixture(input: PathBuf) {
+    let output = input.parent().unwrap().join("output.js");
+    test_fixture(
+        syntax(),
+        &|_tr| {
+            let unresolved_mark = Mark::new();
+            let top_level_mark = Mark::new();
+
+            chain!(
+                resolver(unresolved_mark, top_level_mark, false),
+                optimize_barrel(json(
+                    r#"
+                        {
+                            "wildcard": true
+                        }
+                    "#
+                ))
             )
         },
         &input,

packages/next-swc/crates/core/tests/fixture/named-import-transform/1/output.js

@@ -1,3 +1,3 @@
-import { A, B, C as F } from "__barrel_optimize__?names=A,B,C!=!foo?__barrel_optimize_noop__=A,B,C";
+import { A, B, C as F } from "__barrel_optimize__?names=A,B,C!=!foo";
 import D from 'bar';
 import E from 'baz';

packages/next-swc/crates/core/tests/fixture/named-import-transform/2/output.js

@@ -1,3 +1,3 @@
-import { A, B, C as F } from "__barrel_optimize__?names=A,B,C!=!foo?__barrel_optimize_noop__=A,B,C";
-import { D } from "__barrel_optimize__?names=D!=!bar?__barrel_optimize_noop__=D";
+import { A, B, C as F } from "__barrel_optimize__?names=A,B,C!=!foo";
+import { D } from "__barrel_optimize__?names=D!=!bar";
 import E from 'baz';

packages/next-swc/crates/core/tests/fixture/optimize-barrel/1/input.js → packages/next-swc/crates/core/tests/fixture/optimize-barrel/normal/1/input.js

@@ -1,3 +1,5 @@
+import { z } from './3'
+
 export { foo, b as y } from './1'
 export { x, a } from './2'
 export { z }

packages/next-swc/crates/core/tests/fixture/optimize-barrel/normal/2/output.js

@@ -0,0 +1 @@
+// De-optimize this file

packages/next-swc/crates/core/tests/fixture/optimize-barrel/3/input.js → packages/next-swc/crates/core/tests/fixture/optimize-barrel/normal/3/input.js

@@ -1,6 +1,7 @@
-// De-optimize this file
+import { a as z } from './3'
 export * from 'x'
+export * from 'y'
 
 export { foo, b as y } from './1'
 export { x, a } from './2'
-export { z }
+export { z as w }

packages/next-swc/crates/core/tests/fixture/optimize-barrel/normal/3/output.js

@@ -0,0 +1,3 @@
+export const __next_private_export_map__ = '[["foo","./1","foo"],["y","./1","b"],["x","./2","x"],["a","./2","a"],["w","./3","a"]]';
+export * from "__barrel_optimize__?names=__PLACEHOLDER__!=!x";
+export * from "__barrel_optimize__?names=__PLACEHOLDER__!=!y";

packages/next-swc/crates/core/tests/fixture/optimize-barrel/normal/4/output.js

@@ -0,0 +1,2 @@
+'use client';
+export const __next_private_export_map__ = '[["x","foo","a"],["y","1","y"],["b","foo","b"],["default","foo","default"],["z","bar","default"]]';

packages/next-swc/crates/core/tests/fixture/optimize-barrel/normal/5/output.js

@@ -0,0 +1 @@
+export const __next_private_export_map__ = '[["x","./icons/index.js","*"]]';

packages/next-swc/crates/core/tests/fixture/optimize-barrel/wildcard/1/input.js

@@ -0,0 +1,3 @@
+export const a = 1
+export { b }
+export * from 'c'

packages/next-swc/crates/core/tests/fixture/optimize-barrel/wildcard/1/output.js

@@ -0,0 +1,2 @@
+export const __next_private_export_map__ = '[["a","",""],["b","","b"]]';
+export * from "__barrel_optimize__?names=__PLACEHOLDER__!=!c";

packages/next/src/build/swc/options.ts

@@ -384,9 +384,7 @@ export function getLoaderSWCOptions({
     }
   }
   if (optimizeBarrelExports) {
-    baseOptions.optimizeBarrelExports = {
-      names: optimizeBarrelExports,
-    }
+    baseOptions.optimizeBarrelExports = optimizeBarrelExports
   }
 
   const isNextDist = nextDistPath.test(filename)

packages/next/src/build/webpack-config.ts

@@ -532,10 +532,14 @@ function getModularizeImportAliases(packages: string[]) {
   for (const pkg of packages) {
     try {
       const descriptionFileData = require(`${pkg}/package.json`)
+      const descriptionFilePath = require.resolve(`${pkg}/package.json`)
 
       for (const field of mainFields) {
         if (descriptionFileData.hasOwnProperty(field)) {
-          aliases[pkg] = `${pkg}/${descriptionFileData[field]}`
+          aliases[pkg] = path.join(
+            path.dirname(descriptionFilePath),
+            descriptionFileData[field]
+          )
           break
         }
       }
@@ -1178,7 +1182,7 @@ export default async function getBaseWebpackConfig(
       ...(reactProductionProfiling ? getReactProfilingInProduction() : {}),
 
       // For Node server, we need to re-alias the package imports to prefer to
-      // resolve to the module export.
+      // resolve to the ESM export.
       ...(isNodeServer
         ? getModularizeImportAliases(
             config.experimental.optimizePackageImports || []
@@ -1962,6 +1966,7 @@ export default async function getBaseWebpackConfig(
         'next-invalid-import-error-loader',
         'next-metadata-route-loader',
         'modularize-import-loader',
+        'next-barrel-loader',
       ].reduce((alias, loader) => {
         // using multiple aliases to replace `resolveLoader.modules`
         alias[loader] = path.join(__dirname, 'webpack', 'loaders', loader)
@@ -1977,24 +1982,51 @@ export default async function getBaseWebpackConfig(
     module: {
       rules: [
         {
-          test: /__barrel_optimize__/,
-          use: ({
-            resourceQuery,
-            issuerLayer,
-          }: {
-            resourceQuery: string
-            issuerLayer: string
-          }) => {
-            const names = resourceQuery.slice('?names='.length).split(',')
+          // This loader rule passes the resource to the SWC loader with
+          // `optimizeBarrelExports` enabled. This option makes the SWC to
+          // transform the original code to be a JSON of its export map, so
+          // the barrel loader can analyze it and only keep the needed ones.
+          test: /__barrel_transform__/,
+          use: ({ resourceQuery }: { resourceQuery: string }) => {
+            const isFromWildcardExport = /[&?]wildcard/.test(resourceQuery)
+
             return [
               getSwcLoader({
-                isServerLayer:
-                  issuerLayer === WEBPACK_LAYERS.reactServerComponents,
-                optimizeBarrelExports: names,
+                hasServerComponents: false,
+                optimizeBarrelExports: {
+                  wildcard: isFromWildcardExport,
+                },
               }),
             ]
           },
         },
+        {
+          // This loader rule works like a bridge between user's import and
+          // the target module behind a package's barrel file. It reads SWC's
+          // analysis result from the previous loader, and directly returns the
+          // code that only exports values that are asked by the user.
+          test: /__barrel_optimize__/,
+          use: ({ resourceQuery }: { resourceQuery: string }) => {
+            const names = (
+              resourceQuery.match(/\?names=([^&]+)/)?.[1] || ''
+            ).split(',')
+            const isFromWildcardExport = /[&?]wildcard/.test(resourceQuery)
+
+            return [
+              {
+                loader: 'next-barrel-loader',
+                options: {
+                  names,
+                  wildcard: isFromWildcardExport,
+                },
+                // This is part of the request value to serve as the module key.
+                // The barrel loader are no-op re-exported modules keyed by
+                // export names.
+                ident: 'next-barrel-loader:' + resourceQuery,
+              },
+            ]
+          },
+        },
         ...(hasAppDir
           ? [
               {