syntax: make BinaryNextLine also apply to binary test and arithmetic expressions

[ContinuousCaffeniation]

When using -bn option, only the first of the two examples below is correct. In the second case below, the binary operators are not formatted to be at the beginning of the line. The second example even gets re-formatted, so that the operators, once corrected manually, appear at the end of line again.

#!/bin/bash
# ok, pipes in front of line
if [[ -z "${foo}" ]] \
    || [[ -z "${bar}" ]] \
    || [[ -z "${baz}" ]]; then
    echo "Hello world"
fi

# nok, pipes at the end of line
if [[ -z "${foo}" ||
    -z "${bar}" ||
    -z "${baz}" ]]; then
    echo "Hello world"
fi

[mvdan]

This is a good callout. -bn currently affects BinaryCmd expressions, i.e. foo || bar, but not BinaryTest, such as [[ foo || bar ]]. We also don't apply it to BinaryArithm, e.g. (( foo || bar )).

Note that the docs do correctly document the current status quo:

// BinaryNextLine will make binary operators appear on the next line
// when a binary command, such as a pipe, spans multiple lines. A
// backslash will be used.

It mentions a binary command, so it excludes other forms of binary expressions, like tests and arithmetic.

However, I think it would probably make sense to change the feature to apply to all of them, as they're very similar in terms of how they are formatted. I'll leave this issue open for a few weeks to see if others have thoughts.

[meleu]

I was about to open an issue to report this and fortunately had the idea to search if it was already reported.

Now I'm commenting here in a hope to somehow make the maintainer aware that there are more people interested in having "BinaryNextLine" inside "BinaryTest". :)

btw, many thanks for your work on shfmt! ❤️