go-mnd - Magic number detector for Golang
A vet analyzer to detect magic numbers.
What is a magic number?
A magic number is a numeric literal that is not defined as a constant, but which may change, and therefore can be hard to update. It's considered a bad programming practice to use numbers directly in any source code without an explanation. It makes programs harder to read, understand, and maintain.
Project status
Install
Local
This analyzer requires Golang in version >= 1.12 because it's depends on the go/analysis API.
go get -u github.com/tommy-muehle/go-mnd/v2/cmd/mnd
Github action
You can run go-mnd as a GitHub action as follows:
name: Example workflow
on:
push:
branches:
- master
pull_request:
branches:
- master
jobs:
tests:
runs-on: ubuntu-latest
env:
GO111MODULE: on
steps:
- name: Checkout Source
uses: actions/checkout@v2
- name: Run go-mnd
uses: tommy-muehle/go-mnd@master
with:
args: ./...
GitLab CI
You can run go-mnd inside a GitLab CI pipeline as follows:
stages:
- lint
go:lint:mnd:
stage: lint
needs: []
image: golang:latest
before_script:
- go get -u github.com/tommy-muehle/go-mnd/v2/cmd/mnd
- go mod tidy
- go mod vendor
script:
- go vet -vettool $(which mnd) ./...
Homebrew
To install with Homebrew, run:
brew tap tommy-muehle/tap && brew install tommy-muehle/tap/mnd
Docker
To get the latest available Docker image:
docker pull tommymuehle/go-mnd
Windows
On Windows download the latest release.
Usage
go vet -vettool $(which mnd) ./...
or directly
mnd ./...
or via Docker
docker run --rm -v "$PWD":/app -w /app tommymuehle/go-mnd:latest ./...
Options
The -checks option let's you define a comma separated list of checks.
The -ignored-numbers option let's you define a comma separated list of numbers to ignore.
For example: -ignored-numbers=1000,10_000,3.14159264
The -ignored-functions option let's you define a comma separated list of function name regexp patterns to exclude.
For example: -ignored-functions=math.*,http.StatusText,make
The -ignored-files option let's you define a comma separated list of filename regexp patterns to exclude.
For example: -ignored-files=magic_.*.go,.*_numbers.go
Checks
By default this detector analyses arguments, assigns, cases, conditions, operations and return statements.
- argument
t := http.StatusText(200)
- assign
c := &http.Client{
Timeout: 5 * time.Second,
}
- case
switch x {
case 3:
}
- condition
if x > 7 {
}
- operation
var x, y int
y = 10 * x
- return
return 3
Excludes
By default the numbers 0 and 1 as well as test files are excluded!
Further known excludes
The function "Date" in the "Time" package.
t := time.Date(2017, time.September, 26, 12, 13, 14, 0, time.UTC)
Additional custom excludes can be defined via option flag.
Development
Build
You can build the binary with:
make
Tests
You can run all unit tests using:
make test
And with coverage report:
make test-coverage
Docker image
You can also build locally the docker image by using the command:
make image
Stickers
Just drop me a message via Twitter DM or email if you want some go-mnd stickers for you or your Gopher usergroup.
License
The MIT License (MIT). Please see LICENSE for more information.