Need an option for ignore error when emit declaration

Suggestion

🔍 noEmitOnErrorDeclaration, noEmitOnError for declaration

noEmitOnError do not ignore error when generating declaration files (d.ts)

✅ Viability 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, new syntax sugar for JS, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

⭐ Suggestion

I wonder if this should be a bug or a suggestion.

tsconfig.json has an option noEmitOnError, when set to false compiler generates javascript files and sourcemaps even if some types are missing.

tsconfig.json also has a declaration option for generating d.ts files, when set to true we get errors while generating output files even when noEmitOnError equals false.

📃 Motivating Example

Let's look at the simplest example. A website project that contains only 2 files file.ts and tsconfig.json

• files.ts

function fn(): Coordinate {
    return { x: 0, y: 0 };
}   

• tsconfig.json

{
    "compilerOptions": {
        "noImplicitAny": false,
        "noEmitOnError": false,
        "removeComments": false,
        "declaration": true, // <--- false: okay; true: get errors
        "sourceMap": true,
        "target": "es5"
    },
    "compileOnSave": true
}

The Coordinate is missing type. We can't generate output files.

• (TS4060) Return type of exported function has or is using private name 'Coordinate'
  If we turn off (declaration = false), we can generate output files.

💻 Use Cases

We already have an option to emitOnError for JavaScript files, we should have emitOnError for declaration.

Why did I code and build typescript missing types?

• When I develop, I use Visual Studio with a thousand packages from npm.
• When I built my source code with Using-the-Compiler-API, I didn't install a thousand packages from npm. I'm looking for a way to ignore all errors when emitting output files for both js and d.ts. Right now, we are only able to ignore errors when emitting javascript files.

💡 What workarounds am I using in the meantime?

• When Using-the-Compiler-API, I write a d.ts file manually and add them to the program before call program.emit(). With that trick I can get output in a quick way.

type Coordinate = any;

declare namespace Trade {
    type Order = any;
}

That works fine but it requires more work.

Riproduci l’esempio usando files.ts e tsconfig.json, quindi inizia dal comportamento di program.emit() della compiler API descritto nell’issue. Confronta l’emissione delle dichiarazioni e di JavaScript con noEmitOnError; done fornirebbe un modo controllabile separatamente per emettere i file di dichiarazione nonostante gli errori, con una copertura adeguata.