wsl (whitespace linter) is a linter that wants you to use empty
lines to separate grouping of different types to increase readability. There are
also a few places where it encourages you to remove whitespaces which is at
the start and the end of blocks.
Each check can be disabled or enabled individually to the point where no checks can be run. The idea with this is to attract more users.
This is an exhaustive list of all the checks that can be enabled or disabled and their default value. The names are the same as the Go AST type name for built-ins.
The base rule is that statements that has a block (e.g. for, range,
switch, if etc) should always only be directly adjacent with a single
variable and only if it's used in the expression in the block itself.
For more details and examples, see RULES.
✅ = enabled by default, ❌ = disabled by default
- ✅ assign - Assignments should only be cuddled with other assignments, declarations or increment/decrement
- ✅ branch - Branch statement (
break,continue,fallthrough,goto) should only be cuddled if the block is less thannlines wherenis the value ofbranch-max-lines - ✅ decl - Declarations should never be cuddled
- ✅ defer - Defer should only be cuddled with other
defer, after error checking or with a single variable used on the line above - ✅ expr - Expressions are e.g. function calls or index expressions, they should only be cuddled with variables used on the line above
- ✅ for - For loops should only be cuddled with a single variable used on the line above
- ✅ go - Go should only be cuddled with other
goor a single variable used on the line above - ✅ if - If should only be cuddled with a single variable used on the line above
- ✅ inc-dec - Increment/decrement (
++/--) has the same rules asassign - ✅ label - Labels should never be cuddled
- ✅ range - Range should only be cuddled with a single variable used on the line above
- ✅ return - Return should only be cuddled if the block is less than
nlines wherenis the value ofbranch-max-lines - ✅ select - Select should only be cuddled with a single variable used on the line above
- ✅ send - Send should only be cuddled with a single variable used on the line above
- ✅ switch - Switch should only be cuddled with a single variable used on the line above
- ✅ type-switch - Type switch should only be cuddled with a single variable used on the line above
- ✅ append - Only allow reassigning with
appendif the value being appended exist on the line above - ❌ assign-exclusive - Only allow cuddling either new variables or reassigning of existing ones
- ❌ assign-expr - Don't allow assignments to be cuddled with expressions, e.g. function calls
- ❌ err - Error checking must follow immediately after the error variable is assigned
- ✅ leading-whitespace - Disallow leading empty lines in blocks
- ✅ trailing-whitespace - Disallow trailing empty lines in blocks
Other than enabling or disabling specific checks some checks can be configured in more details.
- ✅ allow-first-in-block - Allow cuddling a variable if it's used first in the immediate following block, even if the statement with the block doesn't use the variable
- ❌ allow-whole-block - Same as above, but allows cuddling if the variable is used anywhere in the following (or nested) block
- branch-max-lines - If a block contains more than this number of lines the
branch statement (e.g.
return,break,continue) need to be separated by a whitespace (default 2) - case-max-lines - If set to a non negative number,
caseblocks needs to end with a whitespace if exceeding this number (default 0, 0 = off, 1 = always) - ❌ include-generated - Include generated files when checking
# Latest release
go install github.com/bombsimon/wsl/v5/cmd/wsl@latest
# Main branch
go install github.com/bombsimon/wsl/v5/cmd/wsl@mainNote: This linter provides a fixer that can fix most issues with the
--fixflag.
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 --default none --enable branch,return --fix ./...wsl is also integrated in golangci-lint
golangci-lint run --no-config --enable-only wsl --fixThis is an exhaustive, default, configuration for wsl in golangci-lint.
linters:
default: none
enable:
- wsl
settings:
wsl:
allow-first-in-block: true
allow-whole-block: false
branch-max-lines: 2
case-max-lines: 0
default: ~ # Can be `all`, `none`, `default` or empty
enable:
- append
- assign
- branch
- decl
- defer
- expr
- for
- go
- if
- inc-dec
- label
- range
- return
- select
- send
- switch
- type-switch
- leading-whitespace
- trailing-whitespace
disable:
- assign-exclusive
- assign-expr
- errnlreturn- Use empty lines beforereturnwhitespace- Don't use a blank newline at the start or end of a block.gofumpt- Stricter formatter thangofmt.