bun.sh/src/meta.zig

const std = @import("std");

pub usingnamespace std.meta;

pub fn ReturnOf(comptime function: anytype) type {
    return ReturnOfType(@TypeOf(function));
}

pub fn ReturnOfType(comptime Type: type) type {
    const typeinfo: std.builtin.Type.Fn = @typeInfo(Type).Fn;
    return typeinfo.return_type orelse void;
}

// partially emulates behaviour of @typeName in previous Zig versions,
// converting "some.namespace.MyType" to "MyType"
pub fn typeBaseName(comptime fullname: []const u8) []const u8 {

    // leave type name like "namespace.WrapperType(namespace.MyType)" as it is
    const baseidx = comptime std.mem.indexOf(u8, fullname, "(");
    if (baseidx != null) return fullname;

    const idx = comptime std.mem.lastIndexOf(u8, fullname, ".");

    const name = if (idx == null) fullname else fullname[(idx.? + 1)..];
    return comptime std.fmt.comptimePrint("{s}", .{name});
}

pub fn enumFieldNames(comptime Type: type) []const []const u8 {
    var names: [std.meta.fields(Type).len][]const u8 = std.meta.fieldNames(Type).*;
    var i: usize = 0;
    for (names) |name| {
        // zig seems to include "_" or an empty string in the list of enum field names
        // it makes sense, but humans don't want that
        if (@import("root").bun.strings.eqlAnyComptime(name, &.{ "_none", "", "_" })) {
            continue;
        }
        names[i] = name;
        i += 1;
    }
    return names[0..i];
}