This addresses ref https://github.com/pytest-dev/pytest/issues/1954.
The current truncation for assertion explanations does not deal with long lines
properly:
- Previously if lines were too long it would display a "-n more lines"
message.
- 999e7c6541 introduced a bug where long lines can
cause index errors if there are < 10 lines.
Extract the truncation logic into its own file and ensure it can deal with
long lines properly.
Part one of https://github.com/pytest-dev/pytest/issues/1512.
If verbosity=1, assertion explanations are truncated at 10 lines. In this
situation, it's more important to tell the user which dictionary items are
different than which are the same.
The assertion reinterpretation is an old backwards compatibility
mode which was no longer being maintained on feature-parity with
the assertion rewriting mode. It was also responsible for some
dubious patching of builtins and test with side-effects would
suddenly start passing. Since re-writing has been the default for
a long time and plugins are now also re-written it is time to
retire reinterpretation.
Hook up the PEP 302 import hook very early in pytest startup so
that it gets installed before setuptools-installed plugins are
imported. Also iterate over all installed plugins and mark them
for rewriting. If an installed plugin is already imported then
a warning is issued, we can not break since that might break
existing plugins and the fallback will still be gracefull to
plain asserts.
Some existing tests are failing in this commit because of the new
warning triggered by inline pytest runs due to the hypothesis
plugin already being imported. The tests will be fixed in the next
commit.
When you don't get enough information with a test running on a CI, it's quite
frustrating, for various reasons:
- It's more likely to be a flaky test, so you might not be able to reproduce
the failure.
- Passing -vv is quite bothersome (creating a temporary commit and reverting
it)
For those reasons, if something goes wrong on CI, it's good to have as much
information as possible.
User provided messages, or any valid expression given as second
argument to the assert statement, are now shown in addition to the
py.test introspection details. Formerly any user provided message
would entirely replace the introspection details.
Fixes issue549.
The new "--tb=auto" option (default) will only display long tracebacks
for the first and last entry. You can get the old behaviour of printing
all entries as long entries with "--tb=long". Also short entries by
default are now printed very similarly to "--tb=native" ones.
The result from the pytest_assertrepr_compare hook should not include
any newlines since that will confuse the mini-formatting language used
by assertion.util.format_explanation. So simply escape the included
newlines, this way hook writers do not have to worry about this at
all.
Fixes issue 453.
If the compared text was in bytes and not actually valid text
(i.e. could not be encoded to text/unicode using the default encoding)
then the assertrepr would fail with an EncodingError. This ensures
that the internal string is always valid unicode, converting any bytes
safely to valid unicode. This is done using repr() which then needs
post-processing to fix the encompassing quotes and un-escape newlines.
This fixes issue 429.
Bruno Oliveira
Matthew Duck
Lev Maximov
Ahn Ki-Wook
Floris Bruynooghe
RedBeardCode
Vasily Kuznetsov
Tom Viner
Marcin Biernat
Florian Bruhin
Ronny Pfannschmidt
holger krekel
Edison Gustavo Muenz
Anatoly Bubenkov
Benjamin Peterson
Mathieu Agopian