How to force error on SwiftLint instead of warnings? - swiftlint

Question

my question is very simple, how do I make all warnings become errors on SwiftLint? (without manually configuring each rule separately)

Answer 1

To integrate SwiftLint to your project, you normally need to add a Run Script Phase, as described by the doc.
If you used the CocoaPods installation, this script would look like:
"${PODS_ROOT}/SwiftLint/swiftlint"
That is where you can customize the command line options. In your case, you may want to use:
"${PODS_ROOT}/SwiftLint/swiftlint" lint --strict
The warnings will still be displayed as warnings, but an extra error will be given, preventing running or archiving:
Command /bin/sh failed with exit code 3
That is the desired error.

Answer 2

One drawback with "--strict" flag is that it won't show which line has a Warning.
You can pipe the output and replace "warning" with "error" by adding:
| sed "s/warning:/error:/"
the whole command will look like:
"${PODS_ROOT}/SwiftLint/swiftlint" lint --strict | sed "s/warning:/error:/"
then Xcode will show all SwiftLint warnings as errors.

Answer 3

You can make every swiftlint rule throw an error by enabling --strict
swiftlint lint --strict
Alternatively, you can configure each rule of swiftlint if you are using a config.yml file so that only certain rules throw an error.
swiftlint lint --config 'config.yml'
In the config.yml file simply add the configuration for the rule you want to throw as an error.
implicit_return:
severity: error
I believe this will work for any swiftlint rule. This is useful if you are looking to gradually adopt a stricter approach to linting.