assert Function
Asserts that a condition is true
and - when enabled - throws an error if it is not.
Assertions are enabled only if the build configuration defines process.env.NODE_ENV
as development
at build time.
Assertions exist solely to assist programmers during development, in the following ways: 1 They allow the programmer to declare conditions that they believe cannot possibly occur. If such conditions occur, they indicate a serious flaw in the programmer's logic. 2 They allow the programmer to assure the TypeScript compiler of the truth of some condition that the compiler cannot itself infer. 3 They allow the author of an API to indicate to consumers of the API a serious misuse that should be corrected during development.
Assertions should never be used to test for conditions - however unlikely - that could be expected to occur at run-time, such as failing to write to a file or load a resource over the network. If the condition asserted ever fails in a production environment, the programmer has made a serious mistake.
Note that even when assertions are disabled, calls to assert
remain in the code and their arguments will be evaluated at run-time.
Therefore, if your condition or message requires computation, prefer to pass it as a function to prevent it from being evaluated when assertions are disabled.
assert(condition: boolean | () => boolean, message?: string | () => string): condition
@throws Error containing the specified message
if condition
is false
.
Returns - condition
Defined in
- core/bentley/src/Assert.ts Line 32
Last Updated: 21 November, 2024