ok(value: unknown, message?: string | Error): asserts value
Tests if value is truthy. It is equivalent toassert.equal(!!value, true, message).
If value is not truthy, an AssertionError is thrown with a messageproperty set equal to the value of the message parameter. If the messageparameter is undefined, a default
error message is assigned. If the messageparameter is an instance of an Error then it will be thrown instead of theAssertionError.
If no arguments are passed in at all message will be set to the string:'No value argument passed to `assert.ok()`'.
Be aware that in the repl the error message will be different to the one
thrown in a file! See below for further details.
importassertfrom'assert/strict';
assert.ok(true); // OK assert.ok(1); // OK
assert.ok(); // AssertionError: No value argument passed to `assert.ok()`
// In the repl: assert.ok(typeof123 === 'string'); // AssertionError: false == true
// In a file (e.g. test.js): assert.ok(typeof123 === 'string'); // AssertionError: The expression evaluated to a falsy value: // // assert.ok(typeof 123 === 'string')
assert.ok(false); // AssertionError: The expression evaluated to a falsy value: // // assert.ok(false)
assert.ok(0); // AssertionError: The expression evaluated to a falsy value: // // assert.ok(0)
importassertfrom'assert/strict';
// Using `assert()` works the same: assert(0); // AssertionError: The expression evaluated to a falsy value: // // assert(0)
Tests if
value
is truthy. It is equivalent toassert.equal(!!value, true, message)
.If
value
is not truthy, anAssertionError
is thrown with amessage
property set equal to the value of themessage
parameter. If themessage
parameter isundefined
, a default error message is assigned. If themessage
parameter is an instance of anError
then it will be thrown instead of theAssertionError
. If no arguments are passed in at allmessage
will be set to the string:'No value argument passed to `assert.ok()`'
.Be aware that in the
repl
the error message will be different to the one thrown in a file! See below for further details.