From e4c27ef0280cb3f97ff44f9b16a6d55f1eb8addc Mon Sep 17 00:00:00 2001
From: michael faith <michaelfaith@users.noreply.github.com>
Date: Sun, 15 Sep 2024 11:12:26 -0500
Subject: [PATCH] fix(utils): export map cache is tainted by unreliable parse
 results

This change addresses and issue observed with the v9 upgrade, where the ExportMap Cache is being tainted with a bad export map, if the parse doesn't yield a `visitorKeys` (which can happen if an incompatible parser is used (e.g. og babel eslint)) for one run of the no-cycle rule.  If a subsequent test is run with a compatible parser, then the bad export map will be found in the cache and used instead of attempting to proceed with the parse.

I also updated the `getExports` test to use a valid parserPath, rather than a mocked one, so that the tests are acting on a valid parserPath.  Otherwise the export map won't be cached following this change.
---
 src/exportMap/builder.js     |  6 +++++-
 tests/src/core/getExports.js | 11 ++++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/exportMap/builder.js b/src/exportMap/builder.js
index 5348dba37..f7b9006ef 100644
--- a/src/exportMap/builder.js
+++ b/src/exportMap/builder.js
@@ -92,7 +92,11 @@ export default class ExportMapBuilder {
 
     exportMap.mtime = stats.mtime;
 
-    exportCache.set(cacheKey, exportMap);
+    // If the visitor keys were not populated, then we shouldn't save anything to the cache,
+    // since the parse results may not be reliable.
+    if (exportMap.visitorKeys) {
+      exportCache.set(cacheKey, exportMap);
+    }
     return exportMap;
   }
 
diff --git a/tests/src/core/getExports.js b/tests/src/core/getExports.js
index 76003410d..da3182a3e 100644
--- a/tests/src/core/getExports.js
+++ b/tests/src/core/getExports.js
@@ -21,7 +21,7 @@ describe('ExportMap', function () {
     },
     {
       settings: {},
-      parserPath: 'babel-eslint',
+      parserPath: require.resolve('babel-eslint'),
     },
   );
 
@@ -41,6 +41,15 @@ describe('ExportMap', function () {
       .to.exist.and.equal(ExportMapBuilder.get('./named-exports', fakeContext));
   });
 
+  it('does not return a cached copy if the parse does not yield a visitor keys', function () {
+    const mockContext = {
+      ...fakeContext,
+      parserPath: 'not-real',
+    }
+    expect(ExportMapBuilder.get('./named-exports', mockContext))
+      .to.exist.and.not.equal(ExportMapBuilder.get('./named-exports', mockContext));
+  });
+
   it('does not return a cached copy after modification', (done) => {
     const firstAccess = ExportMapBuilder.get('./mutator', fakeContext);
     expect(firstAccess).to.exist;