Reduce amount of code necessary to quickly format the diagnostics to a string

Search Terms

FormatDiagnosticsHost

Suggestion

Often when someone is working with the TypeScript compiler API their type checker might have diagnostics. It would be useful for people to quickly check them by typing:

ts.formatDiagnostics(ts.getPreEmitDiagnostics(program))

Instead of:

ts.formatDiagnostics(ts.getPreEmitDiagnostics(program), {
    getCurrentDirectory: () => ts.sys.getCurrentDirectory(),
    getCanonicalFileName: f => f,
    getNewLine: () => "\n"
})

Possible solution is to make providing FormatDiagnosticsHost optional or add a default FormatDiagnosticsHost that people can use (or both).

Also for ts.formatDiagnostic and ts.formatDiagnosticsWithColorAndContext

Use Cases

Easier for people to quickly check the diagnostics while they're developing with the compiler API.

Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• 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.

Related Issues

#29581

Inizia dai punti di ingresso dell’API del compilatore TypeScript formatDiagnostics, formatDiagnostic e formatDiagnosticsWithColorAndContext, quindi traccia come FormatDiagnosticsHost sia attualmente richiesto. Confronta gli approcci proposti con host opzionale e host predefinito, preservando le chiamate esistenti. Il lavoro sarà completato quando sarà possibile formattare rapidamente i diagnostic senza passare un host e il comportamento esistente resterà invariato.