1 Tests naming convention 2 ----------------------- 3 Names of tests (suffixes of control.* files) are build from 2 or 3 words 4 separated by an underscore character. The first one is '100' or 'all', what 5 defines the set of PPD files to test: '100' means 100 chosen (most often used) 6 PPD files (stored in the archive ppds_100) while 'all' means all available PPD 7 files (stored in the archive ppds_all). The second word of the name is either 8 'test' or 'dump'. The third and optional word is 'debug'. All these three words 9 influence testing procedure used by the autotest, their meanings are described 10 in next paragraphs. 11 12 Overall testing procedure 13 ------------------------- 14 The purpose of this autotest is to verify that given subset of PPD files work 15 in ChromeOS. Each PPD file is tested with the following procedure: 16 1. A printer driver is added to CUPS server. 17 2. Test documents are printed on the configured printer. 18 3. Raw output from the CUPS server is intercepted by, so called, FakePrinter. 19 4. CUPS logs are parsed to make sure that no errors occured. 20 5. Obtained outputs are verified (see below) - test only. 21 6. A printing pipeline used by CUPS is rerun in shell (see below) - debug only. 22 7. All obtained outputs & logs are saved on the device (see below) - dump only. 23 8. The printer driver is removed from CUPS server. 24 This procedure is repeated for every PPD file. The number of PPD files may be 25 large (3K+ files). To decrease amount of time needed by the autotest, several 26 PPD files are tested simultaneously in parallel threads. Autotest always run 27 the procedure for all given PPD files and print a summary report at the end. 28 If at least one of PPD files fails, whole autotest is finished with failure 29 (but always all PPD files are processed). 30 31 Output verification ('test') 32 ---------------------------- 33 Intercepted output is verified by comparision with the previous results 34 obtained for the same PPD. We cannot store outputs directly, because their 35 total size may have hundreds of megabytes. Instead of that short digest is 36 calculated for each obtained document and it is used for comparison. 37 A function for digests calculation is in the 'helpers.py' file. Not all 38 outputs can be tested this way because for some PPD files produced contents 39 differ between runs. List of PPD files for which we cannot calculate 40 constant digest is saved in the file digests_blacklist.txt. Files with 41 expected digests for every test document are stored in the directory "digests". 42 If a digests for given pair (test document, PPD file) is missing, the test 43 checks only check if the output is not empty (or not too short). 44 45 Rerun printing pipeline ('debug') 46 --------------------------------- 47 Every PPD file defines printing pipeline used by CUPS, consisting of external 48 binaries (so called filters). To make sure that every part of the printing 49 pipeline works correctly, it can be run outside CUPS in Linux shell. In tests 50 with 'debug' suffix in their names, whole pipeline is rerun outside CUPS. In 51 this mode every document is processed twice: the first time by CUPS and the 52 second time by extracted pipeline run as bash script. Additionally, each 53 pipeline's step is verified by checking its return code (it is supposed to be 54 equal 0) and the final output is compared with the output returned by CUPS 55 server. If the test is also defined as 'dump', each intermediate content is 56 saved to the directory given in path_outputs parameter. 57 This mode requires more disk space on tested device (~2GB in /tmp) and takes 58 more execution time (~2 times more). All information needed to reconstruct 59 a pipeline used by CUPS can are extracted from CUPS logs after the job is 60 completed. To do that, CUPS configuration must be modified: the LogLevel 61 option in /etc/cups/cupsd.conf must be set to "debug". This modification is 62 done when the autotest is initialized; the original setting is restored in 63 the cleaup stage. 64 65 66 Save outputs and logs ('dump') 67 ------------------------------ 68 All obtained outputs and logs are saved on the device in the directory 69 /tmp/PrinterPpds_outputs/. Results obtained from PPD files with the same prefix 70 are grouped together and stored in single archive to limit usage of disk space. 71 72 Test parameters 73 --------------- 74 path_docs - path to directory with test documents (PDF files) 75 path_ppds - path to directory with PPD files, if not set then all available PPD 76 files are downloaded and tested 77 path_digests - path to directory with files containing digests for 78 verification, if not set then outputs are not verified 79 path_outputs - if set, then all outputs are dumped there (given directory is 80 deleted if already exists); also all digests files are recalculated 81 and saved in the same directory 82 debug_mode - True or False, if True then for every test the printing pipeline 83 is extracted from CUPS logs and executed again outside CUPS 84 85 Generating new digests 86 ---------------------- 87 The following procedure can be used to update digests: 88 1. Run the test defined in control.all_dump: 89 test_that <device IP> platform_PrinterPpds.all_dump 90 2. Download generated files with digests to your workstation 91 rsync root@<device IP>:/tmp/PrinterPpds_outputs/*.digests <local dir> 92 3. Replace the files from the "digests" directory and commit changes 93 94 Updating the archive with PPD files 95 ----------------------------------- 96 Currently, all tests are based on PPD files stored in local directories. The 97 autotest can download all PPD files by itself, but we do not use this option 98 to limit the number of possible points of failures during testing. PPD files 99 are stored in the archive 'ppds_all.tar.xz'. To replace the archive with the 100 current list of supported PPD files, one can use the script 101 'download_ppds_make_archive.py'. 102 103 Others 104 ------ 105 * How to get comma-separated list of all used ghostscript devices? 106 1. Go to the directory generated by all_dump_debug 107 2. Unpack all tar.xz archives (not on the device) 108 for d in *.pdf; 109 do 110 cd $d; 111 for f in *.tar.xz; do tar xf $f; done ; 112 cd ..; 113 done 114 3. Run the following 115 grep -o sDEVICE=[^\ ]*\ ./*.pdf/*.err[12345] | cut -d \= -f 2 | sort | uniq | tr -d ' ' | tr '\n' ',' 116 4. Add to the list uniprint (it is not caught by the command above) 117 * How to get a list of all used cups filters? 118 1. Go to the directory generated by all_dump_debug 119 2. Unpack all tar.xz archives (not on the device) 120 for d in *.pdf; 121 do 122 cd $d; 123 for f in *.tar.xz; do tar xf $f; done ; 124 cd ..; 125 done 126 3. Run the following 127 grep -o '(exec -a "Fake[^"]*" [^ ]* ' ./*.pdf/*.sh | cut -d \ -f 4 | sort | uniq 128
