Regression: Maximum call stack exceeded in TypeScript 5.8.3 with large type inference

Description:
We just upgraded our Angular app from version 18 to 20 and, consequently, our TS version to 5.8.3 (the latest compatible version with Angular 20) and are experiencing a "Maximum call stack exceeded" error when compiling our project with TypeScript 5.8.3 - but only in dev mode. It compiles without issue initially, but upon making any changes, we get this error. This appears to be a regression related to complex type inference or large type definitions and did not happen in Angular 18 when using TS 5.3.3.
This only happens in our complex app and not in simpler projects.

Reproduction Steps:

1. Install TypeScript 5.8.3 and and Angular 20 app with complex types.

Expected Behavior:
The project should compile successfully without a "Maximum call stack exceeded" error, as it did in TypeScript 5.3.3 and Angular 18.

Actual Behavior:
The compilation fails with
RangeError: Maximum call stack size exceeded at getTypeAtFlowBranchLabel (/PATH_TO_FILE/node_modules/typescript/lib/typescript.js:74199:38) at getTypeAtFlowNode (/PATH_TO_FILE/node_modules/typescript/lib/typescript.js:74009:48) at getTypeAtFlowCondition (/PATH_TO_FILE/node_modules/typescript/lib/typescript.js:74161:24) at getTypeAtFlowNode (/PATH_TO_FILE/node_modules/typescript/lib/typescript.js:74001:18) at getTypeAtFlowCondition (/PATH_TO_FILE/node_modules/typescript/lib/typescript.js:74161:24) at getTypeAtFlowNode (/PATH_TO_FILE/node_modules/typescript/lib/typescript.js:74001:18) at getTypeAtFlowCondition (/PATH_TO_FILE/node_modules/typescript/lib/typescript.js:74161:24) at getTypeAtFlowNode (/PATH_TO_FILE/node_modules/typescript/lib/typescript.js:74001:18) at getTypeAtFlowCondition (/PATH_TO_FILE/node_modules/typescript/lib/typescript.js:74161:24) at getTypeAtFlowNode (/PATH_TO_FILE/node_modules/typescript/lib/typescript.js:74001:18)

Environment:

• TypeScript Version: 5.8.3
• Angular 20.1.5
• Node.js Version: 22.12.0
• Operating System: MacOS
• Build Tools: Vite - from Angular 20

報告された複雑なアプリケーションで、TypeScript 5.8.3、Angular 20.1.5、Node.js 22.12.0、Viteを使ってまず失敗を再現します。getTypeAtFlowBranchLabel、getTypeAtFlowNode、getTypeAtFlowConditionの周辺のスタックを調査し、その後TypeScript 5.3.3と比較します。インクリメンタルコンパイルがスタックオーバーフローなしで成功するようにリグレッションを特定して解決できれば完了です。