swc/crates/swc_ecma_parser/tests/tsc/enumConstantMembers.ts

// Constant members allow negatives, but not decimals. Also hex literals are allowed
enum E1 {
    a = 1,
    b
}
enum E2 {
    a = - 1,
    b
}
enum E3 {
    a = 0.1,
    b // Error because 0.1 is not a constant
}

declare enum E4 {
    a = 1,
    b = -1,
    c = 0.1 // Not a constant
}

enum E5 {
    a = 1 / 0,
    b = 2 / 0.0,
    c = 1.0 / 0.0,
    d = 0.0 / 0.0,
    e = NaN,
    f = Infinity,
    g = -Infinity
}

const enum E6 {
    a = 1 / 0,
    b = 2 / 0.0,
    c = 1.0 / 0.0,
    d = 0.0 / 0.0,
    e = NaN,
    f = Infinity,
    g = -Infinity
}