Standard library / assert · on the one-page reference

assert

Stable — wraps the language's own panic mechanism, works identically on native and WebAssembly.

A minimal, practical subset of Node's assert module. A failed assertion crashes the program (uncatchable), the same idiom as C's assert() or an uncaught Node AssertionError — not integrated with try/catch.

ok equal
assert.ok(cond)

bool → void — panics if cond is false.

assert.ok(2 + 2 == 4);
console.log("still running");
assert.equal(a, b)

(T, T) → void — panics with both values shown if they are not equal. Strings compare by bytes.

assert.equal(2 + 2, 4);
assert.equal("hello", "hello");
console.log("still running");