Assert
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object Assert
| package nodejs
Alias for emitter.on(eventName, listener).
Alias for emitter.on(eventName, listener).
emitter.addListener(eventName, listener)
on()
An alias of assert.ok() .
An alias of assert.ok() .
the expression to evaluate
assert(value[, message])
Tests for deep equality between the actual and expected parameters.
Tests for deep equality between the actual and expected parameters. Primitive values are compared with the equal comparison operator ( == ). Only enumerable "own" properties are considered. The deepEqual() implementation does not test object prototypes, attached symbols, or non-enumerable properties. This can lead to some potentially surprising results.
assert.deepEqual(actual, expected[, message])
Generally identical to assert.deepEqual() with two exceptions.
Generally identical to assert.deepEqual() with two exceptions. First, primitive values are compared using the strict equality operator ( === ). Second, object comparisons include a strict equality check of their prototypes.
assert.deepStrictEqual(actual, expected[, message])
Asserts that the function block does not throw an error.
Asserts that the function block does not throw an error. See assert.throws() for more details. When assert.doesNotThrow() is called, it will immediately call the block function. If an error is thrown and it is the same type as that specified by the error parameter, then an AssertionError is thrown. If the error is of a different type, or if the error parameter is undefined, the error is propagated back to the caller.
assert.doesNotThrow(block[, error][, message])
Asserts that the function block does not throw an error.
Asserts that the function block does not throw an error. See assert.throws() for more details. When assert.doesNotThrow() is called, it will immediately call the block function. If an error is thrown and it is the same type as that specified by the error parameter, then an AssertionError is thrown. If the error is of a different type, or if the error parameter is undefined, the error is propagated back to the caller.
assert.doesNotThrow(block[, error][, message])
Asserts that the function block does not throw an error.
Asserts that the function block does not throw an error. See assert.throws() for more details. When assert.doesNotThrow() is called, it will immediately call the block function. If an error is thrown and it is the same type as that specified by the error parameter, then an AssertionError is thrown. If the error is of a different type, or if the error parameter is undefined, the error is propagated back to the caller.
assert.doesNotThrow(block[, error][, message])
Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.
Synchronously calls each of the listeners registered for the event named eventName, in the order they were registered, passing the supplied arguments to each.
Returns true if the event had listeners, false otherwise.
the event name
the event arguments
emitter.emit(name[, arg1][, arg2][, ...])
Tests shallow, coercive equality between the actual and expected parameters using the equal comparison operator ( == ).
Tests shallow, coercive equality between the actual and expected parameters using the equal comparison operator ( == ).
assert.equal(actual, expected[, message])
Throws an AssertionError.
Throws an AssertionError. If message is falsy, the error message is set as the values of actual and expected separated by the provided operator. Otherwise, the error message is the value of message.
assert.fail(actual, expected, message, operator)
Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to EventEmitter.defaultMaxListeners.
Returns the current max listener value for the EventEmitter which is either set by emitter.setMaxListeners(n) or defaults to EventEmitter.defaultMaxListeners.
emitter.getMaxListeners()
setMaxListeners()
Throws value if value is truthy.
Throws value if value is truthy. This is useful when testing the error argument in callbacks.
assert.ifError(value)
Returns the number of listeners listening to the event named eventName.
Returns the number of listeners listening to the event named eventName.
emitter.listenerCount(eventName)
Returns a copy of the array of listeners for the event named eventName.
Returns a copy of the array of listeners for the event named eventName.
emitter.listeners(eventName)
Tests for any deep inequality.
Tests for any deep inequality. Opposite of assert.deepEqual().
assert.notDeepEqual(actual, expected[, message])
Tests for deep strict inequality.
Tests for deep strict inequality. Opposite of assert.deepStrictEqual().
assert.notDeepStrictEqual(actual, expected[, message])
Tests shallow, coercive inequality with the not equal comparison operator ( != ).
Tests shallow, coercive inequality with the not equal comparison operator ( != ).
assert.notEqual(actual, expected[, message])
Tests strict inequality as determined by the strict not equal operator ( !== ).
Tests strict inequality as determined by the strict not equal operator ( !== ).
assert.notStrictEqual(actual, expected[, message])
Tests if value is truthy.
Tests if value is truthy. It is equivalent to assert.equal(!!value, true, message). If value is not truthy, an AssertionError is thrown with a message property set equal to the value of the message parameter. If the message parameter is undefined, a default error message is assigned.
Adds the listener function to the end of the listeners array for the event named eventName.
Adds the listener function to the end of the listeners array for the event named eventName. No checks are made to see if the listener has already been added. Multiple calls passing the same combination of eventName and listener will result in the listener being added, and called, multiple times.
Returns a reference to the EventEmitter so calls can be chained.
emitter.on(eventName, listener)
Adds a one time listener function for the event named eventName.
Adds a one time listener function for the event named eventName. This listener is invoked only the next time eventName is triggered, after which it is removed.
emitter.once(eventName, listener)
Removes all listeners, or those of the specified eventName.
Removes all listeners, or those of the specified eventName.
Note that it is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).
Returns a reference to the EventEmitter so calls can be chained.
emitter.removeAllListeners([eventName])
Removes all listeners, or those of the specified eventName.
Removes all listeners, or those of the specified eventName.
Note that it is bad practice to remove listeners added elsewhere in the code, particularly when the EventEmitter instance was created by some other component or module (e.g. sockets or file streams).
Returns a reference to the EventEmitter so calls can be chained.
emitter.removeAllListeners([eventName])
Removes the specified listener from the listener array for the event named eventName.
Removes the specified listener from the listener array for the event named eventName. removeListener will remove, at most, one instance of a listener from the listener array. If any single listener has been added multiple times to the listener array for the specified eventName, then removeListener must be called multiple times to remove each instance.
Note that once an event has been emitted, all listeners attached to it at the time of emitting will be called in order. This implies that any removeListener() or removeAllListeners() calls after emitting and before the last listener finishes execution will not remove them from emit() in progress. Subsequent events will behave as expected.
emitter.removeListener(eventName, listener)
By default EventEmitters will print a warning if more than 10 listeners are added for a particular event.
By default EventEmitters will print a warning if more than 10 listeners are added for a particular event. This is a useful default that helps finding memory leaks. Obviously, not all events should be limited to just 10 listeners. The emitter.setMaxListeners() method allows the limit to be modified for this specific EventEmitter instance. The value can be set to Infinity (or 0) for to indicate an unlimited number of listeners.
Returns a reference to the EventEmitter so calls can be chained.
emitter.setMaxListeners(n)
Tests strict equality as determined by the strict equality operator ( === ).
Tests strict equality as determined by the strict equality operator ( === ).
assert.strictEqual(actual, expected[, message])
If the values are not strictly equal, an AssertionError is thrown with a message property set equal to the value of the message parameter.
If the values are not strictly equal, an AssertionError is thrown with a message property set equal to the value of the message parameter. If the message parameter is undefined, a default error message is assigned.
assert.throws(block[, error][, message])
The assert module provides a simple set of assertion tests that can be used to test invariants. The module is intended for internal use by Node.js, but can be used in application code via require('assert'). However, assert is not a testing framework, and is not intended to be used as a general purpose assertion library.
The API for the assert module is Locked. This means that there will be no additions or changes to any of the methods implemented and exposed by the module.