Node.js assert tracker.calls() Function
The tracker.calls() method is used to keep track of the number of times a function is executed. It returns a wrapper function that should be invoked at exact times. When tracker.verify() is executed, if the method has not been called precisely exact times, tracker.verify() will throw an exception.
Syntax:
tracker.calls([fn][, exact])
Parameters:
- fn: The function to be monitored. A no-op function is the default value.
- exact (number): The number of times. Its default value is 1.
Return Value: A wrapper function that wraps fn.
Example 1:
Javascript
import assert from 'node:assert' ; const tracker = new assert.CallTracker(); function func() { console.log( "Hello World" ) }; const callsfunc = tracker.calls(func, 2); callsfunc(); callsfunc(); process.on( 'exit' , () => { tracker.verify() }); |
Output:
Hello World Hello World
Example 2:
Javascript
import assert from 'node:assert' ; const tracker = new assert.CallTracker(); function func() { console.log( "Hello World" ) }; const callsfunc = tracker.calls(func, 2); callsfunc(); process.on( 'exit' , () => { tracker.verify() }); |
Output:
Reference: https://nodejs.org/api/assert.html#trackercallsfn-exact
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