Test basic functionality

[jangop]

A lot of basic functionality is brittle at the moment. All four implemented tests currently fail.

[sylikc]

@jangop thanks very much for reviewing and testing the v0.5.x branch

Funny thing, I actually had just fixed https://github.com/sylikc/pyexiftool/commit/1089e24ec737744cc511f056669f14abf9fed5fb the ExifToolHelper() breaking when merging your set_tags() PR into this branch. I'll probably fix it in a more robust way in the main ExifTool class later.

I still haven't quite figured out what to do with the -w flag. It really messes up the -j output.

Keep them tests coming! I'm slowly working on the ExifToolHelper class. All the stuff I had merged in before really needs to get revamped. I'll look into the get_metadata lol... I must've dreamt I made that function really robust 😞

[sylikc]

Oh, and yeah the ExifToolHelper currently isn't as robust as the ExifTool class itself. And, I'm pretty new to writing tests.

But I reviewed these failures now, and they do need to be fixed, but how is a good question. For test_read_all_from_no_file and test_read_all_from_nonexistent_file it all boils down to https://github.com/sylikc/pyexiftool/blob/v0.5.x-py3-refactor/exiftool/exiftool.py#L798 and not having decided what an empty JSON should return.

There are legitimate reasons why execute_json will return an empty result. And they're not an error. For example, writing tags returns no output.

I guess it's "possible" to use ExifTool.last_stderr to analyze it from the ExifToolHelper call... maybe.

See this test code:

print( "json =", et.execute_json("rose.jpg", "-JFIF:JFIFVersion") )
print("stderr =", et.last_stderr)

print( "json =", et.execute_json(*["rose.jpg", "-MakerNotes="]) )
print("stderr =", et.last_stderr)

output:

json = [{'SourceFile': 'rose.jpg', 'JFIF:JFIFVersion': '1 1'}]
stderr = b''
json = None
stderr = b'0 image files updated\r\n    1 image files unchanged\r\n'

I guess get_metadata/get_tags should raise an error on a None return from execute_json?

[sylikc]

I'm going to ask on the exiftool forums to see if there's a way to get more error related information from stderr Exiftool force output of "image files read" . That would really solve the problem, or at least allow the helper to do more error checking

[sylikc]

I just pushed a few commits that read out the status code from the last executed command sequence... hopefully that will help the helper determine pass/fail later.

Only problem is, it returns 0 if everything is good, but 1 if one or more failures occurred. It's not a very precise status...

The helper could help parse stderr, but that kinda is going to be messy given that the output from exiftool is more for humans to read

[jangop]

I am all for making this wrapper around `ExifTool robust and convenient, so I really appreciate your effort.