Target not optional (compiler api)

[ivogabe]

The compiler option interface is declared with an optional target property:

    interface CompilerOptions {
        allowNonTsExtensions?: boolean;
        charset?: string;
        codepage?: number;
        declaration?: boolean;
        diagnostics?: boolean;
        emitBOM?: boolean;
        help?: boolean;
        locale?: string;
        mapRoot?: string;
        module?: ModuleKind;
        noEmitOnError?: boolean;
        noErrorTruncation?: boolean;
        noImplicitAny?: boolean;
        noLib?: boolean;
        noLibCheck?: boolean;
        noResolve?: boolean;
        out?: string;
        outDir?: string;
        preserveConstEnums?: boolean;
        removeComments?: boolean;
        sourceMap?: boolean;
        sourceRoot?: string;
        suppressImplicitAnyIndexErrors?: boolean;
        target?: ScriptTarget;
        version?: boolean;
        watch?: boolean;
        [option: string]: string | number | boolean;
    }

But when you provide an empty object {} to the compiler api, certain code won't compile. The last lines of compileNode are:

                if (compilerOptions.target < 2 /* ES6 */) {
                    switch (node.kind) {
                        case 199 /* ShorthandPropertyAssignment */:
                            return emitDownlevelShorthandPropertyAssignment(node);
                        case 125 /* Method */:
                            return emitDownlevelMethod(node);
                    }
                }
                else {
                    ts.Debug.assert(compilerOptions.target >= 2 /* ES6 */, "Invalid ScriptTarget. We should emit as ES6 or above");
                    switch (node.kind) {
                        case 199 /* ShorthandPropertyAssignment */:
                            return emitShorthandPropertyAssignment(node);
                        case 125 /* Method */:
                            return emitMethod(node);
                    }
                }

The Debug.assert will fail, because undefined isn't smaller, equal nor bigger than 2 (ES6). Is this by design, or not? If this is by design, the target property should probably be marked as required.

[mhegazy]

Commit : 65452aa should handle the issue.

[ivogabe]

Thanks, will that fix be released in version 1.4.2?

[mhegazy]

no, in release 1.5, release 1.4.2 is just 1.4 in addition to critical bug fixes.

[ivogabe]

Ok. Just patched it in gulp-typescript, it will set now the target & module by default if they are undefined, so that's working again.