[Home](./index.md) > [rc-js-util](./rc-js-util.md) > [\_Debug](./rc-js-util._debug.md) > [assert](./rc-js-util._debug.assert.md) ## \_Debug.assert() method Throws an `Error` with the given message if the condition is false. **Signature:** ```typescript static assert(this: void, condition: boolean, errorMessage: string): boolean; ``` ## Parameters

Parameter	Type	Description
this	void
condition	boolean
errorMessage	string

**Returns:** boolean A boolean value to make linting happy... ## Remarks If `_BUILD.DISABLE_BREAKPOINT_FLAG` is false or unset then a breakpoint will be hit first. Debug asserts are useful for providing hints to the programmer that they aren't meeting the contract of the API. ## Example ```typescript function foo(a1: number) { // not suitable for a production check, the programmer lied about the input type they supplied _BUILD.DEBUG && _Debug.assert(a1 != null, "a1 must be supplied"); } ```