TypeScript: Function return bitwise flags example

checkUserAccess.js

// After TypeScript compiling
export function checkUserAccess(user) {
    if (!user) {
        return 0;
    }
    const { roles = [] } = user;
    return (0
        | (roles.includes(1 /* checkUserAccess.UserRoles.Admin */) ? 1 /* checkUserAccess.ResultFlags.isAdmin */ : 0)
        | (roles.includes(10 /* checkUserAccess.UserRoles.TestUser */) ? 2 /* checkUserAccess.ResultFlags.isTestUser */ : 0)
        | (roles.includes(11 /* checkUserAccess.UserRoles.ExperimentUser */) ? 4 /* checkUserAccess.ResultFlags.isExperiment */ : 0)
        | (roles.includes(101 /* checkUserAccess.UserRoles.WithFeature1 */) ? 2048 /* checkUserAccess.ResultFlags.hasAceessToFeature1 */ : 0)
        | (roles.includes(102 /* checkUserAccess.UserRoles.WithFeature2 */) ? 4096 /* checkUserAccess.ResultFlags.hasAceessToFeature2 */ : 0)
        | (roles.includes(103 /* checkUserAccess.UserRoles.WithFeature3 */) ? 8192 /* checkUserAccess.ResultFlags.hasAceessToFeature3 */ : 0));
}
const someUser = (globalThis["__currentUser"] || null);
const userAccess = checkUserAccess(someUser);
if ((userAccess & 1 /* checkUserAccess.ResultFlags.isAdmin */) !== 0) {
    console.log('This user is admin:', someUser);
}

checkUserAccess.min.pretty.js

// After terser with pretty
export function checkUserAccess(s) {
    if (!s) {
        return 0;
    }
    const { roles: e = [] } = s;
    return (e.includes(1) ? 1 : 0) | (e.includes(10) ? 2 : 0) | (e.includes(11) ? 4 : 0) | (e.includes(101)
        ? 2048
        : 0) | (e.includes(102) ? 4096 : 0) | (e.includes(103) ? 8192 : 0);
}

const s = globalThis.__currentUser || null;
1 & checkUserAccess(s) && console.log("This user is admin:", s);

checkUserAccess.ts

export function checkUserAccess(user: checkUserAccess.UserInfo | null) {
    if (!user) {
        return 0;
    }

    const { roles = [] } = user;

    return (0
        | (roles.includes(checkUserAccess.UserRoles.Admin) ? checkUserAccess.ResultFlags.isAdmin : 0)
        | (roles.includes(checkUserAccess.UserRoles.TestUser) ? checkUserAccess.ResultFlags.isTestUser : 0)
        | (roles.includes(checkUserAccess.UserRoles.ExperimentUser) ? checkUserAccess.ResultFlags.isExperiment : 0)
        | (roles.includes(checkUserAccess.UserRoles.WithFeature1) ? checkUserAccess.ResultFlags.hasAceessToFeature1 : 0)
        | (roles.includes(checkUserAccess.UserRoles.WithFeature2) ? checkUserAccess.ResultFlags.hasAceessToFeature2 : 0)
        | (roles.includes(checkUserAccess.UserRoles.WithFeature3) ? checkUserAccess.ResultFlags.hasAceessToFeature3 : 0)
    );
}

export namespace checkUserAccess {
    export type UserInfo = {
        roles?: UserRoles[],
    };

    export const enum UserRoles {
        Admin = 1,
        TestUser = 10,
        ExperimentUser = 11,

        WithFeature1 = 101,
        WithFeature2 = 102,
        WithFeature3 = 103,
    }

    export const enum ResultFlags {
        isAdmin = 1 << 0,
        isTestUser = 1 << 1,
        isExperiment = 1 << 2,

        hasAceessToFeature1 = 1 << 11,
        hasAceessToFeature2 = 1 << 12,
        hasAceessToFeature3 = 1 << 13,
    }
}

const someUser = ((globalThis as unknown as { __currentUser?: checkUserAccess.UserInfo | null })["__currentUser"] || null) as (checkUserAccess.UserInfo | null);
const userAccess = checkUserAccess(someUser);

if ((userAccess & checkUserAccess.ResultFlags.isAdmin) !== 0) {
    console.log('This user is admin:', someUser);
}