fix: should only use context.physicalFilename as fallback instead of main source

.changeset/itchy-poets-rush.md

@@ -0,0 +1,5 @@
+---
+"eslint-plugin-import-x": patch
+---
+
+fix: should only use `context.physicalFilename` as fallback instead of main source

src/utils/resolve.ts

@@ -355,7 +355,7 @@ function fullResolve(
         }
 
         // else, counts
-        fileExistsCache.set(cacheKey, resolved.path as string | null)
+        fileExistsCache.set(cacheKey, resolved.path)
         return resolved
       }
     }

test/utils/resolve.spec.ts

@@ -6,17 +6,19 @@ import { setTimeout } from 'node:timers/promises'
 import { jest } from '@jest/globals'
 import type { TSESLint } from '@typescript-eslint/utils'
 
-import { testContext, testFilePath } from '../utils.js'
+import { TEST_FILENAME, testContext, testFilePath } from '../utils.js'
 
-import { importXResolverCompat } from 'eslint-plugin-import-x'
+import { cjsRequire, importXResolverCompat } from 'eslint-plugin-import-x'
 import type {
   CjsRequire,
   NewResolver,
   NormalizedCacheSettings,
+  RuleContext,
 } from 'eslint-plugin-import-x'
 import {
   CASE_SENSITIVE_FS,
   fileExistsWithCaseSync,
+  relative,
   resolve,
 } from 'eslint-plugin-import-x/utils'
 
@@ -830,5 +832,15 @@ describe('resolve', () => {
         }),
       ).toBe(testFilePath('./bar.tsx'))
     })
+
+    it('sourceFile should take higher priority than context.physicalFilename', () => {
+      const sourceFile = cjsRequire.resolve('typescript-eslint')
+      expect(
+        relative('./config-helper', sourceFile, {}, {
+          physicalFilename: TEST_FILENAME,
+          settings: {},
+        } as RuleContext),
+      ).toBe(path.resolve(sourceFile, '../config-helper.js'))
+    })
   })
 })