module: fix null restrictions in imports and exports patterns

lib/internal/modules/esm/resolve.js

@@ -573,27 +573,31 @@ function packageExportsResolve(
   for (let i = 0; i < keys.length; i++) {
     const key = keys[i];
     const patternIndex = StringPrototypeIndexOf(key, '*');
+    const normalizedSubpath = patternIndex !== -1 && exports[key] === null &&
+                              StringPrototypeIncludes(packageSubpath, '//') ?
+      RegExpPrototypeSymbolReplace(/\/+/g, packageSubpath, '/') :
+      packageSubpath;
     if (patternIndex !== -1 &&
-        StringPrototypeStartsWith(packageSubpath,
+        StringPrototypeStartsWith(normalizedSubpath,
                                   StringPrototypeSlice(key, 0, patternIndex))) {
       // When this reaches EOL, this can throw at the top of the whole function:
       //
       // if (StringPrototypeEndsWith(packageSubpath, '/'))
       //   throwInvalidSubpath(packageSubpath)
       //
       // To match "imports" and the spec.
-      if (StringPrototypeEndsWith(packageSubpath, '/'))
-        emitTrailingSlashPatternDeprecation(packageSubpath, packageJSONUrl,
+      if (StringPrototypeEndsWith(normalizedSubpath, '/'))
+        emitTrailingSlashPatternDeprecation(normalizedSubpath, packageJSONUrl,
                                             base);
       const patternTrailer = StringPrototypeSlice(key, patternIndex + 1);
-      if (packageSubpath.length >= key.length &&
-          StringPrototypeEndsWith(packageSubpath, patternTrailer) &&
+      if (normalizedSubpath.length >= key.length &&
+          StringPrototypeEndsWith(normalizedSubpath, patternTrailer) &&
           patternKeyCompare(bestMatch, key) === 1 &&
           StringPrototypeLastIndexOf(key, '*') === patternIndex) {
         bestMatch = key;
         bestMatchSubpath = StringPrototypeSlice(
-          packageSubpath, patternIndex,
-          packageSubpath.length - patternTrailer.length);
+          normalizedSubpath, patternIndex,
+          normalizedSubpath.length - patternTrailer.length);
       }
     }
   }
@@ -666,18 +670,22 @@ function packageImportsResolve(name, base, conditions) {
         for (let i = 0; i < keys.length; i++) {
           const key = keys[i];
           const patternIndex = StringPrototypeIndexOf(key, '*');
+          const normalizedSubpath = patternIndex !== -1 && imports[key] === null &&
+                                    StringPrototypeIncludes(name, '//') ?
+            RegExpPrototypeSymbolReplace(/\/+/g, name, '/') :
+            name;
           if (patternIndex !== -1 &&
-              StringPrototypeStartsWith(name,
+              StringPrototypeStartsWith(normalizedSubpath,
                                         StringPrototypeSlice(key, 0,
                                                              patternIndex))) {
             const patternTrailer = StringPrototypeSlice(key, patternIndex + 1);
-            if (name.length >= key.length &&
-                StringPrototypeEndsWith(name, patternTrailer) &&
+            if (normalizedSubpath.length >= key.length &&
+                StringPrototypeEndsWith(normalizedSubpath, patternTrailer) &&
                 patternKeyCompare(bestMatch, key) === 1 &&
                 StringPrototypeLastIndexOf(key, '*') === patternIndex) {
               bestMatch = key;
               bestMatchSubpath = StringPrototypeSlice(
-                name, patternIndex, name.length - patternTrailer.length);
+                normalizedSubpath, patternIndex, normalizedSubpath.length - patternTrailer.length);
             }
           }
         }
@@ -1124,6 +1132,7 @@ module.exports = {
 const {
   defaultGetFormatWithoutErrors,
 } = require('internal/modules/esm/get_format');
+const console = require('console');
 
 if (policy) {
   const $defaultResolve = defaultResolve;

test/es-module/test-esm-exports.mjs

@@ -74,7 +74,14 @@ import fromInside from '../fixtures/node_modules/pkgexports/lib/hole.js';
     ['pkgexports/invalid1', './invalid1'],
     ['pkgexports/invalid4', './invalid4'],
     // Null mapping
+    ['pkgexports/sub/internal/test', './sub/internal/test'],
+    ['pkgexports/sub//internal/test', './sub//internal/test'],
+    ['pkgexports/sub/internal//test', './sub/internal//test'],
+    ['pkgexports/sub//internal//test', './sub//internal//test'],
+    ['pkgexports/sub/////internal/////test', './sub/////internal/////test'],
     ['pkgexports/null', './null'],
+    ['pkgexports//null', './/null'],
+    ['pkgexports/////null', './////null'],
     ['pkgexports/null/subpath', './null/subpath'],
     // Empty fallback
     ['pkgexports/nofallback1', './nofallback1'],

test/es-module/test-esm-imports.mjs

@@ -79,10 +79,17 @@ const { requireImport, importImport } = importer;
     '#missing',
     // Explicit null import
     '#null',
+    '#subpath/null',
     // No condition match import
     '#nullcondition',
     // Null subpath shadowing
     '#subpath/nullshadow/x',
+    // Null pattern
+    '#subpath/internal/test',
+    '#subpath//internal/test',
+    '#subpath/internal//test',
+    '#subpath//internal//test',
+    '#subpath/////internal/////test',
   ]);
 
   for (const specifier of undefinedImports) {
@@ -94,10 +101,17 @@ const { requireImport, importImport } = importer;
   }
 
   // Handle not found for the defined imports target not existing
-  loadFixture('#notfound').catch(mustCall((err) => {
-    strictEqual(err.code,
-                isRequire ? 'MODULE_NOT_FOUND' : 'ERR_MODULE_NOT_FOUND');
-  }));
+  const nonDefinedImports = new Set([
+    '#notfound',
+    '#subpath//null',
+    '#subpath/////null',
+  ]);
+  for (const specifier of nonDefinedImports) {
+    loadFixture(specifier).catch(mustCall((err) => {
+      strictEqual(err.code,
+                  isRequire ? 'MODULE_NOT_FOUND' : 'ERR_MODULE_NOT_FOUND');
+    }));
+  }
 });
 
 // CJS resolver must still support #package packages in node_modules

test/fixtures/es-modules/pkgimports/package.json

@@ -6,6 +6,8 @@
       "require": "./requirebranch.js"
     },
     "#subpath/*": "./sub/*",
+    "#subpath/internal/*": null,
+    "#subpath/null": null,
     "#subpath/*.asdf": "./test.js",
     "#external": "pkgexports/valid-cjs",
     "#external/subpath/*": "pkgexports/sub/*",