Set explicit void return type in function builder if set by the user

[Legion2]

When the return type is explicitly set to void it should also be set in the generated code explicitly to void. When enabling strict type checking in typescript compiler with the noImplicitAny option, all functions without explicit return type default to any.
Following code must be changed:

typescriptpoet/src/main/java/io/outfoxx/typescriptpoet/FunctionSpec.kt

Lines 107 to 109 in 62d7d4b

	if (returnType != null && returnType != TypeName.VOID) {
	codeWriter.emitCode(CodeBlock.of(": %T", returnType))
	}

[kdubb]

Agreed.

[Legion2]

I created #25

[tinacious]

I agree it would be great to add this to prevent 'functionName', which lacks return-type annotation, implicitly has an 'any' return type.

It's also important to note that noImplicitAny is the default configuration when using strict mode:

In case anyone finding this is interested in a workaround until the issue is addressed, I defined a type alias Void and used that as the value passed to FunctionSpec#returns(). It's kinda gross but it works. 🤷🏻‍♀️ Another option is to add TypeScript and ESLint disabling comments but that would just clear the error rather than enforce a void return type, so I opted for Void:

// Workaround for https://github.com/outfoxx/typescriptpoet/issues/24
val voidType = TypeAliasSpec
    .builder("Void", TypeName.VOID)
    .addTSDoc("Workaround for https://github.com/outfoxx/typescriptpoet/issues/24")
    .build()
fileSpecBuilder.addType(voidType)

val someInterface = InterfaceSpec
    .builder("MyInterface")
    .addFunction(
        FunctionSpec
            .builder("doSomething")
            .addModifiers(Modifier.ABSTRACT)
            .returns(TypeName.implicit("Void"))
            .build()
    )
    .build()
fileSpecBuilder.addType(someInterface)

Which outputs:

/**
 * Workaround for https://github.com/outfoxx/typescriptpoet/issues/24 */
type Void = void;

interface MyInterface {

  doSomething(): Void;

}

[kdubb]

@Legion2 @tinacious I've been quite preoccupied with other projects. I'll spend some time updating this project.

[kdubb]

That includes merging #25 😉