diff options
Diffstat (limited to 'src/testlib/qtestcase.qdoc')
| -rw-r--r-- | src/testlib/qtestcase.qdoc | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/src/testlib/qtestcase.qdoc b/src/testlib/qtestcase.qdoc index e4e1825bb5..72f8cdaf8c 100644 --- a/src/testlib/qtestcase.qdoc +++ b/src/testlib/qtestcase.qdoc @@ -1,6 +1,6 @@ /**************************************************************************** ** -** Copyright (C) 2019 The Qt Company Ltd. +** Copyright (C) 2020 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the documentation of the Qt Toolkit. @@ -109,19 +109,18 @@ continues. If not, a failure is recorded in the test log and the test function returns without attempting any later checks. - Always respect QCOMPARE() parameter semantics. The first parameter passed to it - should always be the actual value produced by the code-under-test, while the - second parameter should always be the expected value. When the values don't - match, QCOMPARE() prints them with the labels \e Actual and \e Expected. - If the parameter order is swapped, debugging a failing test can be confusing. + Always respect QCOMPARE() parameter semantics. The first parameter passed to + it should always be the actual value produced by the code-under-test, while + the second parameter should always be the expected value. When the values + don't match, QCOMPARE() prints them with the labels \e Actual and \e + Expected. If the parameter order is swapped, debugging a failing test can be + confusing and tests expecting zero may fail due to rounding errors. When comparing floating-point types (\c float, \c double, and \c qfloat16), - \l qFuzzyCompare() is used for finite values. Infinities match if they have + \l qFuzzyCompare() is used for finite values. If qFuzzyIsNull() is true for + both values, they are also considered equal. Infinities match if they have the same sign, and any NaN as actual value matches with any NaN as expected - value (even though NaN != NaN, even when they're identical). This means that - expecting 0 can fail when the actual value may be affected by rounding errors. - One solution to this is to offset both actual and expected values by adding - some suitable constant (such as 1). + value (even though NaN != NaN, even when they're identical). QCOMPARE() tries to output the contents of the values if the comparison fails, so it is visible from the test log why the comparison failed. |