a98923507e
If set, all geometries will be reprojected from their original
coordinate reference system to the destination CRS while
iterating over features.
If a CRS has been set as the destination CRS, then the filterRect
parameter should be specified in the same CRS as this destination
CRS.
Additionally, a callback function can be specified on the request
to be called if a transform exception is encountered while
iterating over features.
This is designed to make it easier for scripts and plugins to
correctly reproject layers in an efficient and robust way, instead
of having to implement lots of repeated code themselves and
potentially missing some of the important considerations which
come with reprojecting geometries & bounding boxes.
Now, if a script wants the features from a layer in a specific
CRS, they can call:
crs = QgsCoordinateReferenceSystem('epsg:4326')
request = QgsFeatureRequest().setDestinationCrs(crs)
for f in layer.getFeatures(reqeuest):
print('geometry in 4326 is {}.format(f.geometry().exportToWkt()))
QGIS unit tests
Build tests
Make sure that you have enabled building of tests in CMake.
cmake -DENABLE_TESTS=ON ..
Run tests
You can run all tests using make check.
Note you will need xvfb-run for that (sudo apt-get install xfvb).
Individual tests can be run using ctest.
For example if the output of make check ends like this:
The following tests FAILED:
77 - PyQgsLocalServer (Failed)
You could re-run the failing test with:
ctest -V -R PyQgsLocalServer
The parameter -V enables verbose mode and -R takes a regular expression as
parameter and will only run matching tests.
For python tests, you can run a specific test inside a unit file with something like this:
QGIS_PREFIX_PATH=output PYTHONPATH=output/python:$PYTHONPATH \
python ${srcdir}/tests/src/python/test_qgsvectorfilewriter.py
TestQgsVectorLayer.testOverwriteLayer
Advanced configuration
Postgres
Make sure that you have enabled building of postgres test in CMake.
cmake -DENABLE_TESTS=ON -DENABLE_PGTEST=ON ..
To test the postgres provider you will need to have a database available to which the postgres provider can connect. The server will need to have postgis support enabled.
By default the test uses one of the following connection string:
dbname=qgis_test
service=qgis_test
If these do not match your setup you can set the environment variable
QGIS_PGTEST_DB to the desired connection string. Note that you can
rely on standard libpq environment variables to tweak host, port user
and password (PGHOST, PGPORT, PGUSER, PGPASSWORD).
Please note that the test database needs to be initialized using the sql-scripts:
tests/testdata/provider/testdata_pg*.sql
They take care of activating postgis for the test database and create some tables containing test data.
For convenience, a shell script is provided to create the database and initialize it as needed:
tests/testdata/provider/testdata_pg.sh
Write tests
Instructions about writing tests for the processing framework can be found in a separate README file:
${TOP_SRCDIR}/python/plugins/processing/tests/README.md
Information about labeling tests design and organization:
${TOP_SRCDIR}/tests/testdata/labeling/README.rst
WCS testing information can be found in:
${TOP_SRCDIR}/tests/testdata/raster/README.WCS
About benchmark tests you can read:
${TOP_SRCDIR}/tests/bench/README
Run python tests in GDB
First find out the required environment variables by running the test outside the debugger.
ctest -V -R ProcessingQgisAlgorithmsTest
Which prints for somewhere in the initialization code something like:
export LD_LIBRARY_PATH=NOTFOUND:/home/m-kuhn/dev/cpp/qgis/build-qt5/output/lib:
export PYTHONPATH=/home/m-kuhn/dev/cpp/qgis/build-qt5/output/python/:/home/m-kuhn/dev/cpp/qgis/build-qt5/output/python/plugins:/home/m-kuhn/dev/cpp/qgis/QGIS/tests/src/python:
First, run these two commands in the terminal.
On the following line it says something like:
-- Running /usr/bin/python3 /home/m-kuhn/dev/cpp/qgis/QGIS/python/plugins/processing/tests/QgisAlgorithmsTest.py
Which you can run in gdb with:
gdb -ex r --args /usr/bin/python3 /home/m-kuhn/dev/cpp/qgis/QGIS/python/plugins/processing/tests/QgisAlgorithmsTest.py
Now you can start using the usual gdb (bt etc.) interface or - if you have
installed the appropriate debug tools (adjust for python3!)
even allows doing python introspection (py-bt).