Duplicate Function Implementation

I have one file, app.ts under my scripts folder, that gets copied to wwwroot/scripts by a gulp task. After the gulp task runs, I now also have a wwwroot/scripts/app.ts file, in which the sole function is red-underlined as duplicate. Is this normal, or is my gulp task, below, declared incorrectly?

var paths = {
    scripts: ["scripts/**/*.js", "scripts/**/*.ts", "scripts/**/*.map"]
};

gulp.task("default", function() {
    gulp.src(paths.scripts).pipe(gulp.dest("wwwroot/scripts"));
});

I see the raw app.ts file, from the root scripts folder also gets built into *.js and *.js.map files. Could this have something to do with the 'false positive' duplicate function?