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.

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

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: ./...

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) ./...

To install with Homebrew, run:

brew tap tommy-muehle/tap && brew install tommy-muehle/tap/mnd

To get the latest available Docker image:

docker pull tommymuehle/go-mnd

On Windows download the latest release.

go vet -vettool $(which mnd) ./...

or directly

mnd ./...

or via Docker

docker run --rm -v "$PWD":/app -w /app tommymuehle/go-mnd:latest ./...

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

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

By default the numbers 0 and 1 as well as test files are excluded!

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.

You can build the binary with:

make

You can run all unit tests using:

make test

And with coverage report:

make test-coverage

You can also build locally the docker image by using the command:

make image

Just drop me a message via Twitter DM or email if you want some go-mnd stickers for you or your Gopher usergroup.

The MIT License (MIT). Please see LICENSE for more information.