TypeScript - One-line conditional (":" expected, expression expected)

Question

Converting an Express JS server to TS, and previously functioning JS conditionals are now throwing weird errors.

Example: if (req!.body?.userObj) req.session!.userObj = req.body!.userObj

Running with ts-node works fine and there are no issues. But running tsc to compile throws these errors:

error TS1109: Expression expected.  

55     if (req!.body?.userObj) req.session!.userObj = req.body!.userObj 
                     ~

middleware/payloadHandle.ts:55:27 - 
error TS1005: ':' expected.

55     if (req!.body?.userObj) req.session!.userObj = req.body!.userObj 

Answer 1

您确保 TS 编译器已更新： npm i typescript@latest 。