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
[](https://goreportcard.com/report/github.com/tommy-muehle/go-mnd)
[](https://codecov.io/gh/tommy-muehle/go-mnd)
## 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/cmd/mnd
- go mod tidy
- go mod vendor
script:
- go vet -vettool $(which mnd) ./...
```
### Homebrew
To install with [Homebrew](https://brew.sh/), 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](https://github.com/tommy-muehle/go-mnd/releases).
## Usage
[](https://asciinema.org/a/231021)
```
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`
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