How to check if a file was created by a test?

Code
1

Say I have an executable that creates a file. What’s the best way to write a test to verify the existence of the file.

# Assume the file is created in the same directory as the executable
add_test(NAME create_json_file COMMAND json_creator --name "foobar.json")

Currently the best idea I have is to write a 2nd test, that depends on the prior test.
I used the builtin cat command since it fails when the file doesn’t exist.

add_test(NAME check_json_exists
    COMMAND ${CMAKE_COMMAND} -E cat $<TARGET_FILE_DIR:json_creator>/foobar.json
)
set_tests_properties(check_json_exists PROPERTIES DEPENDS create_json_file)

Is there a more idiomatic way? I think this is pretty clean, but I’m curious.

2

I would create a wrapper script that executes your program and then exits with a failure code if the file does not exist. Then register that wrapper script as the actual test.

The wrapper script could easily be written in cmake itself.

3

You also want to remove the file at the start of the test so that previously passing runs don’t mask new failures.

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