1
0
mirror of https://github.com/mgechev/revive.git synced 2024-11-24 08:32:22 +02:00
revive/README.md

253 lines
11 KiB
Markdown
Raw Normal View History

2018-05-27 01:39:22 +02:00
[![Build Status](https://travis-ci.org/mgechev/revive.svg?branch=master)](https://travis-ci.org/mgechev/revive)
2017-08-28 05:57:46 +02:00
# revive
2018-05-31 22:30:54 +02:00
Fast, configurable, extensible, flexible, and beautiful linter for Go. Drop-in replacement of golint. Most importantly **revive allows you to develop your own rules and build a strict preset for enhancing your development & code review processes**.
2017-08-28 06:05:02 +02:00
2017-08-28 06:00:20 +02:00
<p align="center">
2018-05-30 22:44:18 +02:00
<img src="./assets/logo.png" alt="" width="300">
<br>
Logo by <a href="https://github.com/hawkgs">Georgi Serev</a>
2017-08-28 06:00:20 +02:00
</p>
2017-08-28 05:59:53 +02:00
2018-02-04 23:42:05 +02:00
Here's how `revive` is different from `golint`:
* Allows us to enable or disable rules using a configuration file.
* Allows us to configure the linting rules with a TOML file.
* 2x faster running the same rules as golint.
* Provides functionality for disabling a specific rule or the entire linter for a file or a range of lines.
* `golint` allows this only for generated files.
* Optional type checking. Most rules in golint do not require type checking. If you disable them in the config file, revive will run over 6x faster than golint.
* Provides multiple formatters which let us customize the output.
* Allows us to customize the return code for the entire linter or based on the failure of only some rules.
* _Everyone can extend it easily with custom rules or formatters._
* `Revive` provides more rules compared to `golint`.
2018-02-04 23:42:05 +02:00
2018-05-30 22:42:28 +02:00
<p align="center">
2018-05-30 22:44:18 +02:00
<img src="./assets/demo.svg" alt="" width="700">
2018-05-30 22:42:28 +02:00
</p>
2018-02-04 22:19:24 +02:00
## Usage
2018-05-27 00:17:28 +02:00
Since the default behavior of `revive` is compatible with `golint`, without providing any additional flags, the only difference you'd notice is faster execution.
2018-02-04 22:19:24 +02:00
2018-05-31 03:34:35 +02:00
### Text Editors
* Support for VSCode in [vscode-go](https://github.com/Microsoft/vscode-go/pull/1699).
2018-05-31 03:34:35 +02:00
2018-05-27 01:19:34 +02:00
### Installation
```bash
go get -u github.com/mgechev/revive
```
2018-02-04 22:19:24 +02:00
### Command Line Flags
2018-05-27 00:17:28 +02:00
`revive` accepts three command line parameters:
2018-02-04 22:19:24 +02:00
2018-05-27 00:17:28 +02:00
* `-config [PATH]` - path to config file in TOML format.
* `-exclude [PATTERN]` - 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`), directories (i.e. `./foo/...`), or any combination of the three.
* `-formatter [NAME]` - formatter to be used for the output. The currently available formatters are:
2018-05-26 23:16:38 +02:00
* `default` - will output the failures the same way that `golint` does.
* `json` - outputs the failures in JSON format.
* `friendly` - outputs the failures when found. Shows summary of all the failures.
* `stylish` - formats the failures in a table. Keep in mind that it doesn't stream the output so it might be perceived as slower compared to others.
2018-02-04 22:19:24 +02:00
2018-05-27 00:17:28 +02:00
### Sample Invocations
```shell
revive -config revive.toml -exclude file1.go -exclude file2.go -formatter friendly github.com/mgechev/revive package/...
```
* The command above will use the configuration from `revive.toml`
* `revive` will ignore `file1.go` and `file2.go`
* The output will be formatted with the `friendly` formatter
* The linter will analyze `github.com/mgechev/revive` and the files in `package`
2018-02-04 22:19:24 +02:00
### Configuration
2018-05-27 00:17:28 +02:00
`revive` can be configured with a TOML file. Here's a sample configuration with explanation for the individual properties:
```toml
# When set to false, ignores files with "GENERATED" header, similar to golint
2018-05-27 00:17:28 +02:00
ignoreGeneratedHeader = true
# Sets the default severity to "warning"
severity = "warning"
# Sets the default failure confidence. This means that linting errors
# with less than 0.8 confidence will be ignored.
confidence = 0.8
# Sets the error code for failures with severity "error"
errorCode = 0
# Sets the error code for failures with severity "warning"
warningCode = 0
# Configuration of the `cyclomatic` rule. Here we specify that
# the rule should fail if it detects code with higher complexity than 10.
[rule.cyclomatic]
arguments = [10]
# Sets the severity of the `package-comments` rule to "error".
[rule.package-comments]
severity = "error"
```
2018-02-04 22:19:24 +02:00
2018-02-04 23:42:05 +02:00
### Default Configuration
2018-02-19 08:19:37 +02:00
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 way they are hardcoded in `golint`).
2018-02-04 23:42:05 +02:00
```shell
revive -config defaults.toml github.com/mgechev/revive
```
2018-02-19 08:19:37 +02:00
This will use the configuration file `defaults.toml`, the `default` formatter, and will run linting over the `github.com/mgechev/revive` package.
2018-02-04 23:42:05 +02:00
### Recommended Configuration
```shell
2018-05-27 00:17:28 +02:00
revive -config config.toml -formatter friendly github.com/mgechev/revive
2018-02-04 23:42:05 +02:00
```
2018-05-27 00:17:28 +02:00
This will use `config.toml`, the `friendly` formatter, and will run linting over the `github.com/mgechev/revive` package.
2018-02-04 23:42:05 +02:00
2018-02-19 08:26:59 +02:00
## Available Rules
2018-05-27 01:16:10 +02:00
List of all available rules. The rules ported from `golint` are left unchanged and indicated in the `golit` column.
| Name | Config | Description | `golint` | Typed |
| --------------------- | :----: | :--------------------------------------------------------------- | :------: | :---: |
| `context-keys-type` | n/a | Disallows the usage of basic types in `context.WithValue`. | yes | yes |
| `time-naming` | n/a | Conventions around the naming of time variables. | yes | yes |
| `var-declaration` | n/a | Reduces redundancies around variable declaration. | yes | yes |
| `unexported-return` | n/a | Warns when a public return is from unexported type. | yes | yes |
| `errorf` | n/a | Should replace `error.New(fmt.Sprintf())` with `error.Errorf()` | yes | yes |
| `blank-imports` | n/a | Disallows blank imports | yes | no |
| `context-as-argument` | n/a | `context.Context` should be the first argument of a function. | yes | no |
| `dot-imports` | n/a | Forbids `.` imports. | yes | no |
| `error-return` | n/a | The error return parameter should be last. | yes | no |
| `error-strings` | n/a | Conventions around error strings. | yes | no |
| `error-naming` | n/a | Naming of error variables. | yes | no |
| `exported` | n/a | Naming and commenting conventions on exported symbols. | yes | no |
| `if-return` | n/a | Redundant if when returning an error. | yes | no |
| `increment-decrement` | n/a | Use `i++` and `i--` instead of `i += 1` and `i -= 1`. | yes | no |
| `var-naming` | n/a | Naming rules. | yes | no |
| `package-comments` | n/a | Package commenting conventions. | yes | no |
| `range` | n/a | Prevents redundant variables when iterating over a collection. | yes | no |
| `receiver-naming` | n/a | Conventions around the naming of receivers. | yes | no |
| `indent-error-flow` | n/a | Prevents redundant else statements. | yes | no |
| `argument-limit` | int | Specifies the maximum number of arguments a function can receive | no | no |
| `cyclomatic` | int | Sets restriction for maximum Cyclomatic complexity. | no | no |
| `max-public-structs` | int | The maximum number of public structs in a file. | no | no |
| `file-header` | string | Header which each file should have. | no | no |
2018-02-19 08:26:59 +02:00
2018-02-19 08:40:53 +02:00
## Available Formatters
This section lists all the available formatters and provides a screenshot for each one.
2018-05-26 23:12:02 +02:00
### Friendly
![Friendly formatter](/assets/friendly-formatter.png)
2018-05-26 21:08:02 +02:00
### Stylish
2018-02-19 08:40:53 +02:00
2018-05-26 21:08:02 +02:00
![Stylish formatter](/assets/stylish-formatter.png)
2018-02-19 08:40:53 +02:00
2018-05-26 23:12:02 +02:00
### Default
![Default formatter](/assets/default-formatter.png)
2018-05-27 00:17:28 +02:00
## Extensibility
2018-02-05 01:40:39 +02:00
The tool can be extended with custom rules or formatters. This section contains additional information on how to implement such.
2018-05-27 00:17:28 +02:00
**To extend the linter with a custom rule or a formatter you'll have to push it to this repository or fork it**. This is due to the limited `-buildmode=plugin` support which [works only on Linux (with known issues)](https://golang.org/pkg/plugin/).
2018-02-05 01:40:39 +02:00
### Custom Rule
Each rule needs to implement the `lint.Rule` interface:
```go
type Rule interface {
Name() string
Apply(*File, Arguments) []Failure
}
```
2018-02-19 08:19:37 +02:00
The `Arguments` type is an alias of the type `[]interface{}`. The arguments of the rule are passed from the configuration file.
#### Example
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:
2018-02-05 01:40:39 +02:00
```toml
[rule.ban-struct-name]
2018-02-05 01:41:22 +02:00
arguments = ["Foo"]
2018-02-05 01:40:39 +02:00
```
With the snippet above we:
2018-02-19 08:19:37 +02:00
* Enable the rule with name `ban-struct-name`. The `Name()` method of our rule should return a string which matches `ban-struct-name`.
* Configure the rule with the argument `Foo`. The list of arguments will be passed to `Apply(*File, Arguments)` together with the target file we're linting currently.
2018-02-05 01:40:39 +02:00
A sample rule implementation can be found [here](/rule/argument-limit.go).
### Custom Formatter
Each formatter needs to implement the following interface:
```go
type Formatter interface {
Format(<-chan Failure, RulesConfig) (string, error)
Name() string
}
```
2018-02-19 08:19:37 +02:00
The `Format` method accepts a channel of `Failure` instances and the configuration of the enabled rules. The `Name()` method should return a string different from the names of the already existing rules. This string is used when specifying the formatter when invoking the `revive` CLI tool.
2018-02-05 01:40:39 +02:00
For a sample formatter, take a look at [this file](/formatter/json.go).
2018-05-27 04:13:54 +02:00
## Speed Comparison
Compared to `golint`, `revive` performs better because it lints the files for each individual rule into a separate goroutine. Here's a basic performance benchmark on MacBook Pro Early 2013 run on kubernetes:
### golint
```shell
time golint kubernetes/... > /dev/null
real 0m54.837s
user 0m57.844s
sys 0m9.146s
```
### revive
```shell
2018-06-01 05:00:04 +02:00
# no type checking
time revive -config untyped.toml kubernetes/... > /dev/null
2018-05-27 04:13:54 +02:00
real 0m8.471s
user 0m40.721s
sys 0m3.262s
2018-05-27 04:13:54 +02:00
```
Keep in mind that if you use rules which require type checking, the performance may drop to 2x faster than `golint`:
2018-06-01 04:53:26 +02:00
```shell
2018-06-01 05:00:04 +02:00
# type checking enabled
2018-06-01 04:53:26 +02:00
time revive kubernetes/... > /dev/null
real 0m26.211s
user 2m6.708s
sys 0m17.192s
```
Currently, type checking is enabled by default. If you want to run the linter without type checking, remove all typed rules from the configuration file.
2018-06-01 04:53:26 +02:00
2018-02-04 22:19:24 +02:00
## License
2017-08-28 05:57:46 +02:00
MIT