Add a strict-mode configuration to error on unnecessary awaits

[MLoughry]

Search Terms

TS80007, unnecessary await

Suggestion

Currently, the tsserver gives a warning/quick fix about unnecessary awaits (TS80007). However, there is no configuration to cause the build to error on such cases.

Use Cases

This would allow PR/CI builds to catch cases where an await is used unnecessarily, which can cause significant added code weight when targeting ES versions that do not support native async/await.

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
  • Depending on how you define added restrictions to strict mode, this could be considered breaking
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

[MartinJohns]

Duplicate of #35419?

[MLoughry]

Duplicate of #35419?

Seems like it, yes.