2020-03-10 21:08:28 +00:00

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# 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
[![Build Status](https://travis-ci.org/tommy-muehle/go-mnd.svg?branch=master)](https://travis-ci.org/tommy-muehle/go-mnd)
[![Go Report Card](https://goreportcard.com/badge/github.com/tommy-muehle/go-mnd)](https://goreportcard.com/report/github.com/tommy-muehle/go-mnd)
## Install
This analyzer requires Golang in version >= 1.12 because it's depends on the **go/analysis** API.
```
go get github.com/tommy-muehle/go-mnd/cmd/mnd
```
To install with [Homebrew](https://brew.sh/), run:
```
brew tap tommy-muehle/tap && brew install tommy-muehle/tap/mnd
```
On Windows download the [latest release](https://github.com/tommy-muehle/go-mnd/releases).
## Usage
[![asciicast](https://asciinema.org/a/231021.svg)](https://asciinema.org/a/231021)
```
go vet -vettool $(which mnd) ./...
```
or directly
```
mnd ./...
```
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.
The ```-excludes``` option let's you define a comma separated list of regexp patterns to exclude.
## 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.
## License
The MIT License (MIT). Please see [LICENSE](LICENSE) for more information.