is possible to check only for "git diff"

[steve21124]

Is it possible to check only for git diff section?

here is the scenario, there are several developers checkin the code, I would like to check which developer that violate the rules and send email to that developer

[daniel-beard]

For my projects, I use a script to cull out the violations, as swiftlint is fast enough to lint the entire code relatively quickly. Here's an example script that I use: https://gist.github.com/daniel-beard/db4059e5a351a12060a8

[larslockefeer]

Yes this is possible:

git diff --cached --name-only | while read filename; do
    swiftlint lint --path "$filename";
done

You could even add SwiftLint as a pre-commit hook, such that you cannot commit (without adding a skip option to your commit) without all changed files passing SwiftLint.

[steve21124]

thanks. good input

[mgrebenets]

This works for staged changes only, but not for modified files.
Dropping the --cached part will give you list of modified files.
It also needs to filter out non Swift files. Here's the script I ended up using:

# Run SwiftLint
START_DATE=$(date +"%s")

SWIFT_LINT=/usr/local/bin/swiftlint

# Run SwiftLint for given filename
run_swiftlint() {
    local filename="${1}"
    if [[ "${filename##*.}" == "swift" ]]; then
        ${SWIFT_LINT} autocorrect --path "${filename}"
        ${SWIFT_LINT} lint --path "${filename}"
    fi
}

if [[ -e "${SWIFT_LINT}" ]]; then
    echo "SwiftLint version: $(${SWIFT_LINT} version)"
    # Run for both staged and unstaged files
    git diff --name-only | while read filename; do run_swiftlint "${filename}"; done
    git diff --cached --name-only | while read filename; do run_swiftlint "${filename}"; done
else
    echo "${SWIFT_LINT} is not installed."
    exit 0
fi

END_DATE=$(date +"%s")

DIFF=$(($END_DATE - $START_DATE))
echo "SwiftLint took $(($DIFF / 60)) minutes and $(($DIFF % 60)) seconds to complete."

We put is somewhere in the project, e.g. in Scripts/swiftlint.sh and then in Xcode itself the build phase step is quite short "${SRCROOT}/Scripts/swiftlint.sh". I don't like looking at Xcode project diffs much :)

[lukas1]

you could replace this check if [[ "${filename##*.}" == "swift" ]]; then by git diff --name-only | grep "\.swift" when doing the while loop to only loop on swift files

[mazen-kasser]

@mgrebenets Hi Max, its great to find your answer :)
What is the use of local filename="${1}"? it will work even without this line.

[danilobecke]

hi, I made a bash script to check only modified files
https://github.com/danilobecke/lint/blob/master/lintDiffOnly.sh

[jpsim]

Assuming SwiftLint's cache is working reliably, what's the advantage of doing this?

[marcelofabri]

Assuming SwiftLint's cache is working reliably, what's the advantage of doing this?

One use case I can see would be slowly integrating SwiftLint by requiring only touched files to be without warnings. This way you can avoid a huge reformatting commit for example.

[jpsim]

That's a great use case