A Go Analyzer that checks that the length of a variable's name matches its usage scope:
Variables with short names can be hard to use if the variable is used over a longer span of lines of code. A longer variable name may be easier to comprehend.
The analyzer also checks constants, parameters, named return values, method receivers, and type parameters.
Arbitrary declarations such as f *foo can be ignored, as well as idiomatic ok variables.
Conventional Go parameters such as ctx context.Context or t *testing.T will always be ignored.
Example output
test.go:4:2: variable name 'x' is too short for the scope of its usage (varnamelen)
x := 123
^
test.go:6:2: variable name 'i' is too short for the scope of its usage (varnamelen)
i := 10
^
varnamelen is integrated into golangci-lint (though it may not always be the most recent version.)
Example configuration for golangci-lint:
linters-settings:
varnamelen:
# The longest distance, in source lines, that is being considered a "small scope." (defaults to 5)
# Variables used in at most this many lines will be ignored.
max-distance: 5
# The minimum length of a variable's name that is considered "long." (defaults to 3)
# Variable names that are at least this long will be ignored.
min-name-length: 3
# Check method receivers. (defaults to false)
check-receiver: false
# Check named return values. (defaults to false)
check-return: false
# Check type parameters. (defaults to false)
check-type-param: false
# Ignore "ok" variables that hold the bool return value of a type assertion. (defaults to false)
ignore-type-assert-ok: false
# Ignore "ok" variables that hold the bool return value of a map index. (defaults to false)
ignore-map-index-ok: false
# Ignore "ok" variables that hold the bool return value of a channel receive. (defaults to false)
ignore-chan-recv-ok: false
# Optional list of variable names that should be ignored completely. (defaults to empty list)
ignore-names:
- err
# Optional list of variable declarations that should be ignored completely. (defaults to empty list)
# Entries must be in one of the following forms (see below for examples):
# - for variables, parameters, named return values, method receivers, or type parameters:
# <name> <type> (<type> can also be a pointer/slice/map/chan/...)
# - for constants: const <name>
ignore-decls:
- c echo.Context
- t testing.T
- f *foo.Bar
- e error
- i int
- const C
- T any
- m map[string]intThe cmd/ folder provides a standalone command line utility. You can build it like this:
go build -o varnamelen ./cmd/
Usage
varnamelen: checks that the length of a variable's name matches its scope
Usage: varnamelen [-flag] [package]
A variable with a short name can be hard to use if the variable is used
over a longer span of lines of code. A longer variable name may be easier
to comprehend.
Flags:
-V print version and exit
-all
no effect (deprecated)
-c int
display offending line with this many lines of context (default -1)
-checkReceiver
check method receiver names
-checkReturn
check named return values
-checkTypeParam
check type parameter names
-cpuprofile string
write CPU profile to this file
-debug string
debug flags, any subset of "fpstv"
-fix
apply all suggested fixes
-flags
print analyzer flags in JSON
-ignoreChanRecvOk
ignore 'ok' variables that hold the bool return value of a channel receive
-ignoreDecls value
comma-separated list of ignored variable declarations
-ignoreMapIndexOk
ignore 'ok' variables that hold the bool return value of a map index
-ignoreNames value
comma-separated list of ignored variable names
-ignoreTypeAssertOk
ignore 'ok' variables that hold the bool return value of a type assertion
-json
emit JSON output
-maxDistance int
maximum number of lines of variable usage scope considered 'short' (default 5)
-memprofile string
write memory profile to this file
-minNameLength int
minimum length of variable name considered 'long' (default 3)
-source
no effect (deprecated)
-tags string
no effect (deprecated)
-trace string
write trace log to this file
-v no effect (deprecated)
This package is licensed under the MIT license.