fix: only cache filename lookup, not options

Presumably to avoid excessive stat calls, the return value of
`normalizeOptions()` is cached for each input tsconfig file. But the
return value also depends on the input `options`: eslint configuration
may pass different options for the same tsconfig file.

Instead, cache only the result of the `tryFile()` call.

Author: anomiex

src/normalize-options.ts

@@ -16,7 +16,7 @@ import type { TypeScriptResolverOptions } from './types.js'
 
 export let defaultConfigFile: string
 
-const configFileMapping = new Map<string, TypeScriptResolverOptions>()
+const configFileMapping = new Map<string, string>()
 
 let warned: boolean | undefined
 
@@ -77,17 +77,17 @@ export function normalizeOptions(
   }
 
   if (configFile) {
-    const cachedOptions = configFileMapping.get(configFile)
-    if (cachedOptions) {
-      log('using cached options for', configFile)
-      return cachedOptions
+    let cachedConfigFile: string | undefined = configFileMapping.get(configFile)
+    if (cachedConfigFile) {
+      log('using cached config file for', configFile)
+      configFile = cachedConfigFile
+    } else if (!ensured && configFile !== defaultConfigFile) {
+      cachedConfigFile = tryFile(DEFAULT_TRY_PATHS, false, configFile)
+      configFileMapping.set(configFile, cachedConfigFile)
+      configFile = cachedConfigFile
     }
   }
 
-  if (!ensured && configFile && configFile !== defaultConfigFile) {
-    configFile = tryFile(DEFAULT_TRY_PATHS, false, configFile)
-  }
-
   options = {
     conditionNames: defaultConditionNames,
     extensions: defaultExtensions,
@@ -100,9 +100,5 @@ export function normalizeOptions(
       : undefined,
   }
 
-  if (configFile) {
-    configFileMapping.set(configFile, options)
-  }
-
   return options
 }

tests/e2e/__snapshots__/e2e.spec.ts.snap

@@ -34,15 +34,9 @@ exports[`e2e cases > should exec eslint successfully > dotProject 1`] = `
 
 exports[`e2e cases > should exec eslint successfully > filesWithDifferentOptions 1`] = `
 {
-  "exitCode": 1,
+  "exitCode": 0,
   "stderr": "",
-  "stdout": "
-<ROOT>/tests/e2e/filesWithDifferentOptions/src/a.foo.js
-  1:15  error  Unable to resolve path to module './x'  import-x/no-unresolved
-
-✖ 1 problem (1 error, 0 warnings)
-
-",
+  "stdout": "",
 }
 `;