Move package.json exports support to a config option

packages/core/integration-tests/test/integration/css-exports/package.json

@@ -0,0 +1,5 @@
+{
+  "@parcel/resolver-default": {
+    "packageExports": true
+  }
+}

packages/core/integration-tests/test/integration/less-exports/package.json

@@ -0,0 +1,5 @@
+{
+  "@parcel/resolver-default": {
+    "packageExports": true
+  }
+}

packages/core/integration-tests/test/integration/resolve-exports/index.js

@@ -0,0 +1,3 @@
+import foo from 'foo';
+
+export default 'hello ' + foo;

packages/core/integration-tests/test/integration/resolve-exports/package.json

@@ -0,0 +1,6 @@
+{
+  "private": true,
+  "@parcel/resolver-default": {
+    "packageExports": true
+  }
+}

packages/core/integration-tests/test/integration/sass-exports/package.json

@@ -1,3 +1,6 @@
 {
-  "private": true
-}
+  "private": true,
+  "@parcel/resolver-default": {
+    "packageExports": true
+  }
+}

packages/core/integration-tests/test/integration/stylus-exports/package.json

@@ -0,0 +1,5 @@
+{
+  "@parcel/resolver-default": {
+    "packageExports": true
+  }
+}

packages/core/integration-tests/test/resolver.js

@@ -415,4 +415,13 @@ describe('resolver', function () {
       },
     );
   });
+
+  it('should support package exports config option', async () => {
+    let b = await bundle(
+      path.join(__dirname, '/integration/resolve-exports/index.js'),
+    );
+
+    let output = await run(b);
+    assert.strictEqual(output.default, 'hello bar');
+  });
 });

packages/core/package-manager/src/NodePackageManager.js

@@ -80,6 +80,7 @@ export class NodePackageManager implements PackageManager {
             },
       mode: 2,
       entries: ENTRIES,
+      packageExports: true,
       moduleDirResolver:
         process.versions.pnp != null
           ? (module, from) => {

packages/resolvers/default/src/DefaultResolver.js

@@ -8,13 +8,18 @@ import NodeResolver from '@parcel/node-resolver-core';
 const WEBPACK_IMPORT_REGEX = /^\w+-loader(?:\?\S*)?!/;
 
 export default (new Resolver({
-  loadConfig({options, logger}) {
+  async loadConfig({config, options, logger}) {
+    let conf = await config.getConfig([], {
+      packageKey: '@parcel/resolver-default',
+    });
+
     return new NodeResolver({
       fs: options.inputFS,
       projectRoot: options.projectRoot,
       packageManager: options.packageManager,
       shouldAutoInstall: options.shouldAutoInstall,
       logger,
+      packageExports: conf?.contents?.packageExports ?? false,
     });
   },
   resolve({dependency, specifier, config: resolver}) {

packages/utils/node-resolver-core/src/Wrapper.js

@@ -49,6 +49,7 @@ type Options = {|
   mode?: BuildMode,
   mainFields?: Array<string>,
   extensions?: Array<string>,
+  packageExports?: boolean,
 |};
 
 type ResolveOptions = {|
@@ -99,6 +100,7 @@ export default class NodeResolver {
           options.env,
           this.options.mode,
         ),
+        packageExports: this.options.packageExports ?? false,
         moduleDirResolver:
           process.versions.pnp != null
             ? (module, from) => {

packages/utils/node-resolver-core/src/lib.rs

@@ -9,8 +9,8 @@ use std::{
 };
 
 use parcel_resolver::{
-  ExportsCondition, Extensions, Fields, FileCreateInvalidation, FileSystem, IncludeNodeModules,
-  Invalidations, OsFileSystem, Resolution, ResolverError, SpecifierType,
+  ExportsCondition, Extensions, Fields, FileCreateInvalidation, FileSystem, Flags,
+  IncludeNodeModules, Invalidations, OsFileSystem, Resolution, ResolverError, SpecifierType,
 };
 
 #[napi(object)]
@@ -33,6 +33,7 @@ pub struct JsResolverOptions {
   pub mode: u8,
   pub entries: Option<u8>,
   pub extensions: Option<Vec<String>>,
+  pub package_exports: bool,
 }
 
 struct FunctionRef {
@@ -249,6 +250,8 @@ impl Resolver {
       resolver.extensions = Extensions::Owned(extensions);
     }
 
+    resolver.flags.set(Flags::EXPORTS, options.package_exports);
+
     if let Some(module_dir_resolver) = options.module_dir_resolver {
       let module_dir_resolver = FunctionRef::new(env, module_dir_resolver)?;
       resolver.module_dir_resolver = Some(Arc::new(move |module: &str, from: &Path| {

packages/utils/node-resolver-core/test/resolver.js

@@ -79,12 +79,14 @@ describe('resolver', function () {
       fs: overlayFS,
       projectRoot: rootDir,
       mode: 'development',
+      packageExports: true,
     });
 
     prodResolver = new NodeResolver({
       fs: overlayFS,
       projectRoot: rootDir,
       mode: 'production',
+      packageExports: true,
     });
 
     configCache.clear();