Fix bug in Named Exports rule that could cause false positives for re-exported values

Author: andrewbranch

.changeset/silly-rings-brake.md

@@ -0,0 +1,5 @@
+---
+"@arethetypeswrong/core": patch
+---
+
+Fix bug in Named Exports rule that could cause false positives for re-exported values

packages/cli/test/snapshots.test.ts

@@ -42,6 +42,7 @@ const tests = [
   ],
 
   ["eslint-module-utils@2.8.1.tgz", "--entrypoints-legacy --ignore-rules=cjs-only-exports-default"],
+  ["@cerbos__core@0.18.1.tgz"],
 ];
 
 const defaultOpts = "-f table-flipped";

packages/cli/test/snapshots/@cerbos__core@0.18.1.tgz.md

@@ -0,0 +1,21 @@
+# @cerbos__core@0.18.1.tgz
+
+```
+$ attw @cerbos__core@0.18.1.tgz -f table-flipped
+
+
+@cerbos/core v0.18.1
+
+ No problems found 🌟
+
+
+┌────────────────┬────────┬───────────────────┬───────────────────┬─────────┐
+│                │ node10 │ node16 (from CJS) │ node16 (from ESM) │ bundler │
+├────────────────┼────────┼───────────────────┼───────────────────┼─────────┤
+│ "@cerbos/core" │ 🟢     │ 🟢 (CJS)          │ 🟢 (CJS)          │ 🟢      │
+└────────────────┴────────┴───────────────────┴───────────────────┴─────────┘
+
+
+```
+
+Exit code: 0

packages/core/src/internal/esm/cjsNamespace.ts

@@ -2,30 +2,27 @@ import { Package } from "../../createPackage.js";
 import { getCjsModuleBindings } from "./cjsBindings.js";
 import { cjsResolve } from "./cjsResolve.js";
 
-export function getCjsModuleNamespace(fs: Package, file: URL, seen = new Set<string>()) {
+export function getCjsModuleNamespace(fs: Package, file: URL, seen = new Set<string>()): Set<string> {
   seen.add(file.pathname);
-  const { exports, reexports } = getCjsModuleBindings(fs.readFile(file.pathname));
+  const exports = new Set<string>();
+  const bindings = getCjsModuleBindings(fs.readFile(file.pathname));
+  bindings.exports.forEach((name) => exports.add(name));
 
   // CJS always exports `default`
-  if (!exports.includes("default")) {
-    exports.push("default");
+  if (!exports.has("default")) {
+    exports.add("default");
   }
 
   // Additionally, resolve facade reexports
-  const lastResolvableReexport = (() => {
-    for (const source of reexports.reverse()) {
-      try {
-        return cjsResolve(fs, source, file);
-      } catch {}
-    }
-  })();
-  if (
-    lastResolvableReexport &&
-    lastResolvableReexport.format === "commonjs" &&
-    !seen.has(lastResolvableReexport.resolved.pathname)
-  ) {
-    const extra = getCjsModuleNamespace(fs, lastResolvableReexport.resolved, seen);
-    exports.push(...extra.filter((name) => !exports.includes(name)));
+
+  for (const source of bindings.reexports.reverse()) {
+    try {
+      const { format, resolved } = cjsResolve(fs, source, file);
+      if (format === "commonjs" && !seen.has(resolved.pathname)) {
+        const reexported = getCjsModuleNamespace(fs, resolved, seen);
+        reexported.forEach((name) => exports.add(name));
+      }
+    } catch {}
   }
 
   return exports;

packages/core/src/internal/esm/esmNamespace.ts

@@ -22,7 +22,7 @@ export function getEsmModuleNamespace(
   seen.add(resolved.pathname);
 
   if (format === "commonjs") {
-    return getCjsModuleNamespace(fs, resolved);
+    return [...getCjsModuleNamespace(fs, resolved)];
   }
 
   // Parse module bindings