Tests naming convention ----------------------- Names of tests (suffixes of control.* files) are build from 2 or 3 words separated by an underscore character. The first one is '100' or 'all', what defines the set of PPD files to test: '100' means 100 chosen (most often used) PPD files (stored in the archive ppds_100) while 'all' means all available PPD files (stored in the archive ppds_all). The second word of the name is either 'test' or 'dump'. The third and optional word is 'debug'. All these three words influence testing procedure used by the autotest, their meanings are described in next paragraphs. Overall testing procedure ------------------------- The purpose of this autotest is to verify that given subset of PPD files work in ChromeOS. Each PPD file is tested with the following procedure: 1. A printer driver is added to CUPS server. 2. Test documents are printed on the configured printer. 3. Raw output from the CUPS server is intercepted by, so called, FakePrinter. 4. CUPS logs are parsed to make sure that no errors occured. 5. Obtained outputs are verified (see below) - test only. 6. A printing pipeline used by CUPS is rerun in shell (see below) - debug only. 7. All obtained outputs & logs are saved on the device (see below) - dump only. 8. The printer driver is removed from CUPS server. This procedure is repeated for every PPD file. The number of PPD files may be large (3K+ files). To decrease amount of time needed by the autotest, several PPD files are tested simultaneously in parallel threads. Autotest always run the procedure for all given PPD files and print a summary report at the end. If at least one of PPD files fails, whole autotest is finished with failure (but always all PPD files are processed). Output verification ('test') ---------------------------- Intercepted output is verified by comparision with the previous results obtained for the same PPD. We cannot store outputs directly, because their total size may have hundreds of megabytes. Instead of that short digest is calculated for each obtained document and it is used for comparison. A function for digests calculation is in the 'helpers.py' file. Not all outputs can be tested this way because for some PPD files produced contents differ between runs. List of PPD files for which we cannot calculate constant digest is saved in the file digests_blacklist.txt. Files with expected digests for every test document are stored in the directory "digests". If a digests for given pair (test document, PPD file) is missing, the test checks only check if the output is not empty (or not too short). Rerun printing pipeline ('debug') --------------------------------- Every PPD file defines printing pipeline used by CUPS, consisting of external binaries (so called filters). To make sure that every part of the printing pipeline works correctly, it can be run outside CUPS in Linux shell. In tests with 'debug' suffix in their names, whole pipeline is rerun outside CUPS. In this mode every document is processed twice: the first time by CUPS and the second time by extracted pipeline run as bash script. Additionally, each pipeline's step is verified by checking its return code (it is supposed to be equal 0) and the final output is compared with the output returned by CUPS server. If the test is also defined as 'dump', each intermediate content is saved to the directory given in path_outputs parameter. This mode requires more disk space on tested device (~2GB in /tmp) and takes more execution time (~2 times more). All information needed to reconstruct a pipeline used by CUPS can are extracted from CUPS logs after the job is completed. To do that, CUPS configuration must be modified: the LogLevel option in /etc/cups/cupsd.conf must be set to "debug". This modification is done when the autotest is initialized; the original setting is restored in the cleaup stage. Save outputs and logs ('dump') ------------------------------ All obtained outputs and logs are saved on the device in the directory /tmp/PrinterPpds_outputs/. Results obtained from PPD files with the same prefix are grouped together and stored in single archive to limit usage of disk space. Test parameters --------------- path_docs - path to directory with test documents (PDF files) path_ppds - path to directory with PPD files, if not set then all available PPD files are downloaded and tested path_digests - path to directory with files containing digests for verification, if not set then outputs are not verified path_outputs - if set, then all outputs are dumped there (given directory is deleted if already exists); also all digests files are recalculated and saved in the same directory debug_mode - True or False, if True then for every test the printing pipeline is extracted from CUPS logs and executed again outside CUPS Generating new digests ---------------------- The following procedure can be used to update digests: 1. Run the test defined in control.all_dump: test_that platform_PrinterPpds.all_dump 2. Download generated files with digests to your workstation rsync root@:/tmp/PrinterPpds_outputs/*.digests 3. Replace the files from the "digests" directory and commit changes Updating the archive with PPD files ----------------------------------- Currently, all tests are based on PPD files stored in local directories. The autotest can download all PPD files by itself, but we do not use this option to limit the number of possible points of failures during testing. PPD files are stored in the archive 'ppds_all.tar.xz'. To replace the archive with the current list of supported PPD files, one can use the script 'download_ppds_make_archive.py'. Others ------ * How to get comma-separated list of all used ghostscript devices? 1. Go to the directory generated by all_dump_debug 2. Unpack all tar.xz archives (not on the device) for d in *.pdf; do cd $d; for f in *.tar.xz; do tar xf $f; done ; cd ..; done 3. Run the following grep -o sDEVICE=[^\ ]*\ ./*.pdf/*.err[12345] | cut -d \= -f 2 | sort | uniq | tr -d ' ' | tr '\n' ',' 4. Add to the list uniprint (it is not caught by the command above) * How to get a list of all used cups filters? 1. Go to the directory generated by all_dump_debug 2. Unpack all tar.xz archives (not on the device) for d in *.pdf; do cd $d; for f in *.tar.xz; do tar xf $f; done ; cd ..; done 3. Run the following grep -o '(exec -a "Fake[^"]*" [^ ]* ' ./*.pdf/*.sh | cut -d \ -f 4 | sort | uniq