fix: unecessary program updates by removing timeout methods

packages/typescript-estree/src/create-program/createWatchProgram.ts

@@ -250,7 +250,7 @@ function createWatchProgram(
       filePath === currentLintOperationState.filePath
         ? currentLintOperationState.code
         : oldReadFile(filePath, encoding);
-    if (fileContent) {
+    if (fileContent !== undefined) {
       parsedFilesSeenHash.set(filePath, createHash(fileContent));
     }
     return fileContent;
@@ -309,25 +309,30 @@ function createWatchProgram(
       );
     oldOnDirectoryStructureHostCreate(host);
   };
-
-  /*
-   * The watch change callbacks TS provides us all have a 250ms delay before firing
-   * https://github.com/microsoft/TypeScript/blob/b845800bdfcc81c8c72e2ac6fdc2c1df0cdab6f9/src/compiler/watch.ts#L1013
-   *
-   * We live in a synchronous world, so we can't wait for that.
-   * This is a bit of a hack, but it lets us immediately force updates when we detect a tsconfig or directory change
-   */
-  const oldSetTimeout = watchCompilerHost.setTimeout;
-  watchCompilerHost.setTimeout = (cb, ms, ...args): unknown => {
-    if (ms === 250) {
-      cb();
-      return null;
+  watchCompilerHost.trace = log;
+
+  // Since we don't want to asynchronously update program we want to disable timeout methods
+  // So any changes in the program will be delayed and updated when getProgram is called on watch
+  // But because of https://github.com/microsoft/TypeScript/pull/37308 we cannot just set it to undefined
+  // instead save it and call before getProgram is called
+  let callback: (() => void) | undefined;
+  watchCompilerHost.setTimeout = (cb, _ms, ...args): unknown => {
+    callback = cb.bind(/*this*/ undefined, ...args);
+    return callback;
+  };
+  watchCompilerHost.clearTimeout = (): void => {
+    callback = undefined;
+  };
+  const watch = ts.createWatchProgram(watchCompilerHost);
+  const originalGetProgram = watch.getProgram;
+  watch.getProgram = (): ts.SemanticDiagnosticsBuilderProgram => {
+    if (callback) {
+      callback();
     }
-
-    return oldSetTimeout?.(cb, ms, ...args);
+    callback = undefined;
+    return originalGetProgram.call(watch);
   };
-
-  return ts.createWatchProgram(watchCompilerHost);
+  return watch;
 }
 
 function hasTSConfigChanged(tsconfigPath: CanonicalPath): boolean {