assertTrue() in Python is a unittest library function that is used in unit testing to compare test value with true. This function will take two parameters as input and return a boolean value depending upon the assert condition. If test value is true then assertTrue() will return true else return false.
Syntax: assertTrue(testValue, message)
Parameters: assertTrue() accepts two parameters which are listed below with explanation:
- testValue: variable of boolean type which is used in the comparison by function
- message: a string sentence as a message which got displayed when the test case got failed.
Listed below are two different examples illustrating the positive and negative test case for given assert function:
Example 1: Negative Test case
# unit test case import unittest
class TestStringMethods(unittest.TestCase):
# test function
def test_negative( self ):
testValue = False
# error message in case if test case got failed
message = "Test value is not true."
# assertTrue() to check true of test value
self .assertTrue( testValue, message)
if __name__ = = '__main__' :
unittest.main()
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Output:
F ====================================================================== FAIL: test_negative (__main__.TestStringMethods) ---------------------------------------------------------------------- Traceback (most recent call last): File "p1.py", line 11, in test_negative self.assertTrue( testValue, message) AssertionError: False is not true : Test value is not true. ---------------------------------------------------------------------- Ran 1 test in 0.000s FAILED (failures=1)
Example 2: Positive Test case
# unit test case import unittest
class TestStringMethods(unittest.TestCase):
# test function
def test_positive( self ):
testValue = True
# error message in case if test case got failed
message = "Test value is not true."
# assertTrue() to check true of test value
self .assertTrue( testValue, message)
if __name__ = = '__main__' :
unittest.main()
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Output:
. ---------------------------------------------------------------------- Ran 1 test in 0.000s OK
Reference: https://docs.python.org/3/library/unittest.html