wsl

README

wsl - Whitespace Linter

wsl is a linter that enforces a very non scientific vision of how to make code more readable by enforcing empty lines at the right places.

This linter is aggressive and a lot of projects I've tested it on have failed miserably. For this linter to be useful at all I want to be open to new ideas, configurations and discussions! Also note that some of the warnings might be bugs or unintentional false positives so I would love an issue to fix, discuss, change or make something configurable!

Installation

# Latest release
go install github.com/bombsimon/wsl/v4/cmd/wsl@latest

# Main branch
go install github.com/bombsimon/wsl/v4/cmd/wsl@master

Usage

Note: This linter provides a fixer that can fix most issues with the --fix flag. However, currently golangci-lint does not support suggested fixes so the --fix flag in golangci-lint will not work.

wsl uses the analysis package meaning it will operate on package level with the default analysis flags and way of working.

wsl --help
wsl [flags] </path/to/package/...>

wsl --allow-cuddle-declarations --fix ./...

wsl is also integrated in golangci-lint

golangci-lint run --no-config --disable-all --enable wsl

Issues and configuration

The linter suppers a few ways to configure it to satisfy more than one kind of code style. These settings could be set either with flags or with YAML configuration if used via golangci-lint.

The supported configuration can be found in the documentation.

Below are the available checklist for any hit from wsl. If you do not see any, feel free to raise an issue.

Note: this linter doesn't take in consideration the issues that will be fixed with go fmt -s so ensure that the code is properly formatted before use.

• Anonymous switch statements should never be cuddled
• Append only allowed to cuddle with appended value
• Assignments should only be cuddled with other assignments
• Block should not end with a whitespace (or comment)
• Block should not start with a whitespace
• Case block should end with newline at this size
• Branch statements should not be cuddled if block has more than two lines
• Declarations should never be cuddled
• Defer statements should only be cuddled with expressions on same variable
• Expressions should not be cuddled with blocks
• Expressions should not be cuddled with declarations or returns
• For statement without condition should never be cuddled
• For statements should only be cuddled with assignments used in the iteration
• Go statements can only invoke functions assigned on line above
• If statements should only be cuddled with assignments
• If statements should only be cuddled with assignments used in the if statement itself
• If statements that check an error must be cuddled with the statement that assigned the error
• Only cuddled expressions if assigning variable or using from line above
• Only one cuddle assignment allowed before defer statement
• Only one cuddle assignment allowed before for statement
• Only one cuddle assignment allowed before go statement
• Only one cuddle assignment allowed before if statement
• Only one cuddle assignment allowed before range statement
• Only one cuddle assignment allowed before switch statement
• Only one cuddle assignment allowed before type switch statement
• Ranges should only be cuddled with assignments used in the iteration
• Return statements should not be cuddled if block has more than two lines
• Short declarations should cuddle only with other short declarations
• Switch statements should only be cuddled with variables switched
• Type switch statements should only be cuddled with variables switched

Documentation

Index

• func NewAnalyzer(config *Configuration) *analysis.Analyzer
• type Configuration

Functions

func NewAnalyzer

func NewAnalyzer(config *Configuration) *analysis.Analyzer

Types

type Configuration

type Configuration struct {
	// StrictAppend will do strict checking when assigning from append (x =
	// append(x, y)). If this is set to true the append call must append either
	// a variable assigned, called or used on the line above. Example on not
	// allowed when this is true:
	//
	//  x := []string{}
	//  y := "not going in X"
	//  x = append(x, "not y") // This is not allowed with StrictAppend
	//  z := "going in X"
	//
	//  x = append(x, z) // This is allowed with StrictAppend
	//
	//  m := transform(z)
	//  x = append(x, z) // So is this because Z is used above.
	StrictAppend bool

	// AllowAssignAndCallCuddle allows assignments to be cuddled with variables
	// used in calls on line above and calls to be cuddled with assignments of
	// variables used in call on line above.
	// Example supported with this set to true:
	//
	//  x.Call()
	//  x = Assign()
	//  x.AnotherCall()
	//  x = AnotherAssign()
	AllowAssignAndCallCuddle bool

	// AllowAssignAndAnythingCuddle allows assignments to be cuddled with anything.
	// Example supported with this set to true:
	//  if x == 1 {
	//  	x = 0
	//  }
	//  z := x + 2
	// 	fmt.Println("x")
	//  y := "x"
	AllowAssignAndAnythingCuddle bool

	// AllowMultiLineAssignCuddle allows cuddling to assignments even if they
	// span over multiple lines. This defaults to true which allows the
	// following example:
	//
	//  err := function(
	//  	"multiple", "lines",
	//  )
	//  if err != nil {
	//  	// ...
	//  }
	AllowMultiLineAssignCuddle bool

	// If the number of lines in a case block is equal to or lager than this
	// number, the case *must* end white a newline.
	ForceCaseTrailingWhitespaceLimit int

	// AllowTrailingComment will allow blocks to end with comments.
	AllowTrailingComment bool

	// AllowSeparatedLeadingComment will allow multiple comments in the
	// beginning of a block separated with newline. Example:
	//  func () {
	//		// Comment one
	//
	//		// Comment two
	// 		fmt.Println("x")
	//  }
	AllowSeparatedLeadingComment bool

	// AllowCuddleDeclaration will allow multiple var/declaration statements to
	// be cuddled. This defaults to false but setting it to true will enable the
	// following example:
	//  var foo bool
	//  var err error
	AllowCuddleDeclaration bool

	// AllowCuddleWithCalls is a list of call idents that everything can be
	// cuddled with. Defaults to calls looking like locks to support a flow like
	// this:
	//
	//  mu.Lock()
	//  allow := thisAssignment
	AllowCuddleWithCalls []string

	// AllowCuddleWithRHS is a list of right hand side variables that is allowed
	// to be cuddled with anything. Defaults to assignments or calls looking
	// like unlocks to support a flow like this:
	//
	//  allow := thisAssignment()
	//  mu.Unlock()
	AllowCuddleWithRHS []string

	// ForceCuddleErrCheckAndAssign will cause an error when an If statement that
	// checks an error variable doesn't cuddle with the assignment of that variable.
	// This defaults to false but setting it to true will cause the following
	// to generate an error:
	//
	// err := ProduceError()
	//
	// if err != nil {
	//     return err
	// }
	ForceCuddleErrCheckAndAssign bool

	// When ForceCuddleErrCheckAndAssign is enabled this is a list of names
	// used for error variables to check for in the conditional.
	// Defaults to just "err"
	ErrorVariableNames []string

	// ForceExclusiveShortDeclarations will cause an error if a short declaration
	// (:=) cuddles with anything other than another short declaration. For example
	//
	// a := 2
	// b := 3
	//
	// is allowed, but
	//
	// a := 2
	// b = 3
	//
	// is not allowed. This logic overrides ForceCuddleErrCheckAndAssign among others.
	ForceExclusiveShortDeclarations bool

	// IncludeGenerated will include generated files in the analysis and report
	// errors even for generated files. Can be useful when developing
	// generators.
	IncludeGenerated bool
}

Configuration represents configurable settings for the linter.