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//! Runtime detection of whether we're in node.js or a browser.

use js_sys;
use wasm_bindgen::prelude::*;
use wasm_bindgen::JsCast;

#[wasm_bindgen]
extern "C" {
    type This;
    #[wasm_bindgen(method, getter, structural, js_name = self)]
    fn self_(me: &This) -> JsValue;
}

/// Returns whether it's likely we're executing in a browser environment, as
/// opposed to node.js.
// If this function is inlined then there's no other functions in this module
// (which becomes an object file) to actually pull in the custom section listed
// above. Force this to never be inlined so if this module is needed its forced
// to pull in the descriptor section from `#[wasm_bindgen]` above.
#[inline(never)]
pub fn is_browser() -> bool {
    // Test whether we're in a browser by seeing if the `self` property is
    // defined on the global object, which should in turn only be true in
    // browsers.
    js_sys::global().unchecked_into::<This>().self_() != JsValue::undefined()
}