robotframework / robotframework/SeleniumLibrary

Infinity Loop with `Capture ** Screenshot` when using `{{index}}` (escaped) while file exists

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@emanlove is already working on this.

Since Jan 20, 2024.

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Description

The following atest should be updated to this, so that the screenshot is taken twice.

Capture page screenshot with escaped braces
    ${file} =    Capture Page Screenshot    ${OUTPUTDIR}/screenshot-and-index/brackets-{{index}}-name.png
    File Should Exist    ${OUTPUTDIR}/screenshot-and-index/brackets-{index}-name.png
    ${file} =    Capture Page Screenshot    ${OUTPUTDIR}/screenshot-and-index/brackets-{{index}}-name.png    # this line is new!
    Should Be Equal    ${file}    ${OUTPUTDIR}${/}screenshot-and-index${/}brackets-{index}-name.png
    ${file} =    Capture Page Screenshot    ${OUTPUTDIR}/screenshot-and-index/brackets-{{index-name.png
    File Should Exist    ${OUTPUTDIR}/screenshot-and-index/brackets-{index-name.png

The problem is, that the code of _get_screenshot_path() does increment the index and then checks if either the (original) filename is equal to the formatted filename, which would mean that there was no {index} in it, or the file does not exists.

So that mean if the filename is before and after formatting the same, it does not matter if it exists, it will be overwritten.

BUT there is one special feature, that you can include {index} in the final file name, by doubling the braces.

So filename-{{index}}.png will be filename-{index}.png in the filesystem.
The problem now is, that the original filename (filename-{{index}}.png) is not equal with the formatted filename filename-{index}.png and therefore the index is increased. But there is no replaceable index in the original name, so the while loop is infinit.

The fix would be to compare not the original with the formatted, but two formatted with different index numbers with each other.

This is the fixed code:

    def _get_screenshot_path(self, filename):
        if self._screenshot_root_directory != EMBED:
            directory = self._screenshot_root_directory or self.log_dir
        else:
            directory = self.log_dir
        filename = filename.replace("/", os.sep)
        index = 0
        while True:
            index += 1
            formatted = _format_path(filename, index)
            formatted_control = _format_path(filename, sys.maxsize)   # control group with max int
            path = os.path.join(directory, formatted)
            # filename didn't contain {index} or unique path was found
            if formatted == formatted_control or not os.path.exists(path):    # two formatted texts are compared.
                return path

kind regards
René

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