Upgrading from 1.0.0 to 1.1.0 causes "additionalProperties": false to be dropped.

[Jason3S]

This is a preliminary report.

I'll investigate further to provide a simple repo case.

Using git bisect, the issue started with #1367

[Jason3S]

@daanboer,

I'll take a looks at the cause, but maybe you have an idea why additionalProperties gets dropped from some types.

[domoritz]

Good catch. Thanks for looking into it. I can make a new release when we have a fix.

[daanboer]

@Jason3S I am currently a bit short on time, but I can take a look if you provide a minimal example.

[Jason3S]

@daanboer,

I found the cause and have a quick fix. But, there might be some improvement.

Cause: Hidden types become NeverType and NeverType.additionalProperties is undefined by definition.

ts-json-schema-generator/src/NodeParser/HiddenTypeNodeParser.ts

Line 16 in 065ac27

return new NeverType();

When combined with other types, additionalProperties bleeds into the final type:

ts-json-schema-generator/src/Utils/allOfDefinition.ts

Lines 87 to 92 in 065ac27

	if (
	(other.additionalProperties || other.additionalProperties === undefined) &&
	definition.additionalProperties == false
	) {
	delete definition.additionalProperties;
	}

Possible fix:

        if (
            (other.additionalProperties || other.additionalProperties === undefined) &&
            definition.additionalProperties == false &&
            !(baseType instanceof NeverType)
        ) {
            delete definition.additionalProperties;
        }

But a better fix might be to make a HiddenType that extends NeverType and a HiddenTypeFormatter:

export class HiddenTypeFormatter implements SubTypeFormatter {
    public supportsType(type: HiddenType): boolean {
        return type instanceof HiddenType;
    }
    public getDefinition(type: HiddenType): Definition {
        return { not: {}, additionalProperties: false };
    }
    public getChildren(type: HiddenType): BaseType[] {
        return [];
    }
}

[daanboer]

@Jason3S Nice find, personally I think it makes sense to introduce a HiddenType. However, I don't know whether it will need special casing in other regions of the code. Also, you can omit the not: {} in the return of getDefinition as additionalProperties is false anyway (and it just clutters the generated schema).

[Jason3S]

@domoritz,

Thank you for releasing 1.1.1.

[domoritz]

Thanks for the fix