separate exportsOnly handling

readme.md

@@ -59,26 +59,31 @@ By default `processCwd` is the same as `base`.
 
 #### Exports
 
-By default tracing of the [Node.js "exports" field](https://nodejs.org/dist/latest-v14.x/docs/api/esm.html#esm_package_entry_points) is not handled, but can be enabled by setting the exports option:
+By default tracing of the [Node.js "exports" field](https://nodejs.org/dist/latest-v14.x/docs/api/esm.html#esm_package_entry_points) is supported, with the `"node"`, `"require"`, `"import"` and `"default"` conditions traced as defined.
+
+Alternatively the explicit list of exports can be provided:
 
 ```js
 const { fileList } = await nodeFileTrace(files, {
-  exports: true
+  exports: ['node', 'production']
 });
 ```
 
-By default, the `"node"`, `"require"`, `"import"` and `"default"` conditions will be traced. Any package with an `"exports"` field will have its
-exports traced instead of the `"main"`.
+Only the `"node"` export should be explicitly included (if needed) when specifying the exact export condition list. The `"require"`, `"import"` and `"default"` conditions will always be traced as defined, no matter what custom conditions are set.
+
+#### Exports Only
 
-In addition to a boolean value, the specific list of exports conditions to trace can be provided as well:
+When tracing exports the `"main"` / index field will still be traced for Node.js versions without `"exports"` support.
+
+This can be disabled with the `exportsOnly` option:
 
 ```js
 const { fileList } = await nodeFileTrace(files, {
-  exports: ['node', 'production']
+  exportsOnly: true
 });
 ```
 
-Only the `"node"` export should be explicitly included (if needed) when specifying the exact export condition list. The `"require"`, `"import"` and `"default"` conditions will always be traced as defined, no matter what custom conditions are set.
+Any package with `"exports"` will then only have its exports traced, and the main will not be included at all.
 
 #### Paths
 

src/node-file-trace.js

@@ -43,7 +43,8 @@ class Job {
   constructor ({
     base = process.cwd(),
     processCwd,
-    exports = false,
+    exports = ['node'],
+    exportsOnly = false,
     paths = {},
     ignore,
     log = false,
@@ -74,9 +75,8 @@ class Job {
     }
     this.base = base;
     this.cwd = resolve(processCwd || base);
-    if (!Array.isArray(exports) && typeof exports !== 'boolean')
-      exports = false;
-    this.exports = exports === true ? ['node'] : exports;
+    this.exports = exports;
+    this.exportsOnly = exportsOnly;
     const resolvedPaths = {};
     for (const path of Object.keys(paths)) {
       const trailer = paths[path].endsWith('/');
@@ -282,26 +282,44 @@ class Job {
       ...[...deps].map(async dep => {
         try {
           var resolved = await resolveDependency(dep, path, this, !isESM);
-          // ignore builtins
-          if (resolved.startsWith('node:')) return;
         }
         catch (e) {
           this.warnings.add(new Error(`Failed to resolve dependency ${dep}:\n${e && e.message}`));
           return;
         }
-        await this.emitDependency(resolved, path);
+        if (Array.isArray(resolved)) {
+          for (const item of resolved) {
+            // ignore builtins
+            if (item.startsWith('node:')) return;
+            await this.emitDependency(item, path);
+          }
+        }
+        else {
+          // ignore builtins
+          if (resolved.startsWith('node:')) return;
+          await this.emitDependency(resolved, path);
+        }
       }),
       ...[...imports].map(async dep => {
         try {
           var resolved = await resolveDependency(dep, path, this, false);
-          // ignore builtins
-          if (resolved.startsWith('node:')) return;
         }
         catch (e) {
           this.warnings.add(new Error(`Failed to resolve dependency ${dep}:\n${e && e.message}`));
           return;
         }
-        await this.emitDependency(resolved, path);
+        if (Array.isArray(resolved)) {
+          for (const item of resolved) {
+            // ignore builtins
+            if (item.startsWith('node:')) return;
+            await this.emitDependency(item, path);
+          }
+        }
+        else {
+          // ignore builtins
+          if (resolved.startsWith('node:')) return;
+          await this.emitDependency(resolved, path);
+        }
       })
     ]);
   }

src/resolve-dependency.js

@@ -12,7 +12,9 @@ module.exports = function resolveDependency (specifier, parent, job, cjsResolve
   else {
     resolved = resolvePackage(specifier, parent, job, cjsResolve);
   }
-  if (resolved.startsWith('node:')) return resolved;
+  if (typeof resolved === 'string' && resolved.startsWith('node:')) return resolved;
+  if (Array.isArray(resolved))
+    return resolved.map(resolved => job.realpath(resolved, parent));
   return job.realpath(resolved, parent);
 };
 
@@ -145,11 +147,16 @@ function resolvePackage (name, parent, job, cjsResolve) {
     if (!stat || !stat.isDirectory()) continue;
     const pkgCfg = getPkgCfg(nodeModulesDir + sep + pkgName, job);
     if (pkgCfg && job.exports && pkgCfg.exports !== undefined && pkgCfg.exports !== null) {
+      let legacyResolved;
+      if (!job.exportsOnly)
+        legacyResolved = resolveFile(nodeModulesDir + sep + name, parent, job) || resolveDir(nodeModulesDir + sep + name, parent, job);
       let resolved = resolveExportsTarget(nodeModulesDir + sep + pkgName, pkgCfg.exports, '.' + name.slice(pkgName.length), job, cjsResolve);
       if (resolved && cjsResolve)
         resolved = resolveFile(resolved, parent, job) || resolveDir(resolved, parent, job);
       if (resolved) {
         job.emitFile(nodeModulesDir + sep + pkgName + sep + 'package.json', 'resolve', parent);
+        if (legacyResolved && legacyResolved !== resolved)
+          return [resolved, legacyResolved];
         return resolved;
       }
     }

test/unit.test.js

@@ -56,7 +56,7 @@ for (const unitTest of fs.readdirSync(join(__dirname, 'unit'))) {
         dep: 'test/unit/esm-paths/esm-dep.js',
         'dep/': 'test/unit/esm-paths-trailer/'
       },
-      exports: unitTest.startsWith('exports'),
+      exportsOnly: unitTest.startsWith('exports-only'),
       ts: true,
       log: true,
       // disable analysis for basic-analysis unit tests

test/unit/exports-only/input.js

@@ -0,0 +1,2 @@
+require('pkg');
+

test/unit/exports-only/output.js

@@ -0,0 +1,8 @@
+[
+  "package.json",
+  "test/unit/exports-only/input.js",
+  "test/unit/exports-only/node_modules/pkg/package.json",
+  "test/unit/exports-only/node_modules/pkg/require-main.cjs",
+  "test/unit/exports-only/node_modules/pkg/subdir/import-main.js",
+  "test/unit/exports-only/node_modules/pkg/subdir/package.json"
+]

test/unit/exports/output.js

@@ -1,6 +1,7 @@
 [
   "package.json",
   "test/unit/exports/input.js",
+  "test/unit/exports/node_modules/pkg/index.js",
   "test/unit/exports/node_modules/pkg/package.json",
   "test/unit/exports/node_modules/pkg/require-main.cjs",
   "test/unit/exports/node_modules/pkg/subdir/import-main.js",