revive

Fast, configurable, extensible, flexible, and beautiful linter for Go.

Here's how revive is different from golint:

Allows you to enable or disable rules using a configuration file.
Allows you to configure the linting rules with a configuration file.
Provides functionality to disable a specific rule or the entire linter for a file or a range of lines.
Provides more rules compared to golint.
Provides multiple formatters which let you customize the output.
Allows you to customize the return code for the entire linter or based on the failure of only some rules.
Open for addition of new rules or formatters.
Faster since it runs the rules over each file in a separate goroutine.

Usage

Revive is configurable linter which you can fit your needs. By default you can use revive with the default configuration options. This way the linter will work the same way golint does.

Command Line Flags

Revive accepts only three command line parameters:

config - path to config file in TOML format.
exclude - pattern for files/directories/packages to be excluded for linting. You can specify the files you want to exclude for linting either as package name (i.e. github.com/mgechev/revive), list them as individual files (i.e. file.go file2.go), directories (i.e. ./foo/...), or any combination of the three.
formatter - formatter to be used for the output. The currently available formatters are:
- default - will output the warnings the same way that golint does.
- json - outputs the warnings in JSON format.
- cli - formats the warnings in a table.

Configuration

Revive can be configured with a TOML file

Default Configuration

The default configuration of revive can be found at defaults.toml. This will enable all rules available in golint and use their default configuration (i.e. the config which is hardcoded in golint).

revive -config defaults.toml github.com/mgechev/revive

This will use defaults.toml, the default formatter, and will run linting over the github.com/mgechev/revive package.

Recommended Configuration

revive -config config.toml -formatter cli github.com/mgechev/revive

This will use config.toml, the cli formatter, and will run linting over the github.com/mgechev/revive package.

Extension

The tool can be extended with custom rules or formatters. This section contains additional information on how to implement such.

To extend the linter with a custom rule or a formatter you'll have to push it to this repository. This is due to the limited -buildmode=plugin support which works only on Linux.

Custom Rule

Each rule needs to implement the lint.Rule interface:

type Rule interface {
	Name() string
	Apply(*File, Arguments) []Failure
}

The Arguments type is an alias of the type []interface{} which means that you can pass arguments from any type to your rule. Let's suppose we have developed a rule called BanStructNameRule which disallow us to name a structure with given identifier. We can set the banned identifier by using the TOML configuration file:

[rule.ban-struct-name]
  arguments: ["Foo"]

With the snippet above we:

Enable the rule ban-struct-name which is supposed to be the value returned by the Name() method of our rule.
Pass an argument with value "Foo" to the Apply method of the rule once invoked with a file.

A sample rule implementation can be found here.

Custom Formatter

Each formatter needs to implement the following interface:

type Formatter interface {
	Format(<-chan Failure, RulesConfig) (string, error)
	Name() string
}

The Format method accepts a channel of Failure instances and the configuration the enabled rules. The Name() method should return an string different from the names of the already existing rules.

For a sample formatter, take a look at this file.

License

MIT

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