Fix failures on long CRAM test scripts with internal commands that can consume stdin - #48
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nmerinov wants to merge 1 commit into
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Fix failures on long CRAM test scripts with internal commands that can consume stdin#48nmerinov wants to merge 1 commit into
nmerinov wants to merge 1 commit into
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Some of applications could consume data from stdin, when stdin is not empty. As the result, when we trying to pass shell script through stdin of shell process some data can be processed by such consumers instead of desired shell process. In order to solve this provide the following changes: * cram/_process.py: Add new named "script" argument for the "execute()" function. Users can pass arguments either as "script" or as "stdin". The "stdin" capability preserved to run "patch" utility from "cram/_cli.py". * cram/_test.py: Run tests through "script" option instead of "stdin". This change required to make sure that internal test commands can't steal data targeted for shell process. * tests/debug.t: Replace test option from "-s" to "-x", because now test commands passed through file, not through stdin. * tests/consume-stdin.py: Test utility that can steal data from stdin if it available. * tests/stdin-consumers-in-test.t: Create trivial test which contains more than 8KB of commands, to be sure that shell will not read all of them from stdin at once. On each command run the "consume-stdin.py" script in order to steal remainging data from stdin before shell will read them for own execution. Signed-off-by: Nikolai Merinov <n.merinov@inango-systems.com> Reported-by: Petr Štetiar <petr.stetiar@prplfoundation.org>
kynan
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Aug 9, 2026
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| et up cram alias and example tests: |
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| Exercise cram script with determenistic output that consumes extra stdin if any after each command | |||
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| Exercise cram script with determenistic output that consumes extra stdin if any after each command | |
| Exercise cram script with deterministic output that consumes extra stdin if any after each command |
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Why so many test case? What's the benefit?
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During work on CRAM-based testsuite in prplFoundation we observed the issue that CRAM tests where text for the commands longer than 8KB can fail with error messages like the following:
+ /bin/sh: 72: Syntax error: Unterminated quoted string (no-eol)After investigation we found that failures related to the commands that can try to read from
stdinif there are any data available instdin. You can find minimal example in the providedtests/stdin-consumers-in-test.t.With current CRAM implementation this test fails with the following error:
Root cause of the issue
Currently CRAM execute all tests in the following manner:
/bin/shprocess and send all commands to it's stdin.stdin.Suggested solution
In order to solve the issue with such commands we suggest to send commands to shell through shell script instead of piping it to stdin.
This made with new arguments
cram._process.execute()function. Newexecute()implementation can get eitherscript=b'commands'argument for test fromcram/_test.py, orstdin=b'patch text'argument for usage fromcram/_cli.py.