tabPermtationsRefactored.ts

// Hidden types
type TwoTabPanel = {
    kind: 'TwoTabPanel',
    tab1: Tab,
    tab2: Tab
};
type ThreeTabPanel = {
    kind: 'ThreeTabPanel',
    tab1: Tab,
    tab2: Tab,
    tab3: Tab
};
type FourTabPanel = {
    kind: 'FourTabPanel',
    tab1: Tab,
    tab2: Tab,
    tab3: Tab,
    tab4: Tab
};

// Exposed constructor functions
export function twoTabPanel(highlightedBorder: Border, activeIndex: number, { tab1, tab2 }): TabPanelButtonProps {
    return {
        tabs: {
            kind: 'TwoTabPanel',
            tab1: tab1,
            tab2: tab2
        },
        highlightedBorder,
        activeIndex
    };
}

export function threeTabPanel(highlightedBorder: Border, activeIndex: number, { tab1, tab2, tab3 }): TabPanelButtonProps {
    // ...
}

export function fourTabPanel(highlightedBorder: Border, activeIndex: number, { tab1, tab2, tab3, tab4 }): TabPanelButtonProps {
    // ..
}