Constructor for AssertionError.
A descriptive message that explains the assertion failure. This message will be included in the error stack trace.
OptionalstackStaticstackThe Error.stackTraceLimit property specifies the number of stack frames
collected by a stack trace (whether generated by new Error().stack or
Error.captureStackTrace(obj)).
The default value is 10 but may be set to any valid JavaScript number. Changes
will affect any stack trace captured after the value has been changed.
If set to a non-number value, or set to a negative number, stack traces will not capture any frames.
StaticcaptureCreates a .stack property on targetObject, which when accessed returns
a string representing the location in the code at which
Error.captureStackTrace() was called.
const myObject = {};
Error.captureStackTrace(myObject);
myObject.stack; // Similar to `new Error().stack`
The first line of the trace will be prefixed with
${myObject.name}: ${myObject.message}.
The optional constructorOpt argument accepts a function. If given, all frames
above constructorOpt, including constructorOpt, will be omitted from the
generated stack trace.
The constructorOpt argument is useful for hiding implementation
details of error generation from the user. For instance:
function a() {
b();
}
function b() {
c();
}
function c() {
// Create an error without stack trace to avoid calculating the stack trace twice.
const { stackTraceLimit } = Error;
Error.stackTraceLimit = 0;
const error = new Error();
Error.stackTraceLimit = stackTraceLimit;
// Capture the stack trace above function b
Error.captureStackTrace(error, b); // Neither function c, nor b is included in the stack trace
throw error;
}
a();
OptionalconstructorOpt: FunctionStaticprepare
AssertionErroris a custom error type used to indicate assertion failures in tests or validation utilities. This error is intended to be thrown by assertion methods (such as those in a custom Assert class) when a condition that should always be true is found to be false. Using a specificAssertionErrortype allows for more precise error handling and clearer reporting in test environments, as assertion failures can be easily distinguished from other kinds of runtime errors.Example
Features:
Remarks
This class is intentionally simple—no extra methods or properties are added, to keep assertion failures clear and unambiguous.