feat: add links to rules in formatters

This PR introduces:

- A new formatter called "plain" which produces the same output as "default" but also appends link to the rule
- The "friendly" and "stylish" formatters now have URLs to the rules instead of the rule names
- Update of the README, adding the "unix" and "plain" formatters

README.md

@@ -300,15 +300,29 @@ This section lists all the available formatters and provides a screenshot for ea
 
 ### Friendly
 
-![Friendly formatter](/assets/friendly-formatter.png)
+![Friendly formatter](/assets/formatter-friendly.png)
 
 ### Stylish
 
-![Stylish formatter](/assets/stylish-formatter.png)
+![Stylish formatter](/assets/formatter-stylish.png)
 
 ### Default
 
-![Default formatter](/assets/default-formatter.png)
+The default formatter produces the same output as `golint`.
+
+![Default formatter](/assets/formatter-default.png)
+
+### Plain
+
+The plain formatter produces the same output as the default formatter and appends URL to the rule description.
+
+![Plain formatter](/assets/formatter-plain.png)
+
+### Unix
+
+The unix formatter produces the same output as the default formatter but surrounds the rules in `[]`.
+
+![Unix formatter](/assets/formatter-unix.png)
 
 ## Extensibility
 

config.go

@@ -82,6 +82,7 @@ var allFormatters = []lint.Formatter{
 	&formatter.Default{},
 	&formatter.Unix{},
 	&formatter.Checkstyle{},
+	&formatter.Plain{},
 }
 
 func getFormatters() map[string]lint.Formatter {

formatter/default.go

@@ -7,7 +7,7 @@ import (
 )
 
 // Default is an implementation of the Formatter interface
-// which formats the errors to JSON.
+// which formats the errors to text.
 type Default struct {
 	Metadata lint.FormatterMetadata
 }

formatter/friendly.go

@@ -72,7 +72,7 @@ func (f *Friendly) printHeaderRow(failure lint.Failure, severity lint.Severity)
 	if severity == lint.SeverityError {
 		emoji = errorEmoji
 	}
-	fmt.Print(f.table([][]string{{emoji, failure.RuleName, color.GreenString(failure.Failure)}}))
+	fmt.Print(f.table([][]string{{emoji, "https://revive.run/r#" + failure.RuleName, color.GreenString(failure.Failure)}}))
 }
 
 func (f *Friendly) printFilePosition(failure lint.Failure) {

formatter/plain.go

@@ -0,0 +1,26 @@
+package formatter
+
+import (
+	"fmt"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// Plain is an implementation of the Formatter interface
+// which formats the errors to JSON.
+type Plain struct {
+	Metadata lint.FormatterMetadata
+}
+
+// Name returns the name of the formatter
+func (f *Plain) Name() string {
+	return "plain"
+}
+
+// Format formats the failures gotten from the lint.
+func (f *Plain) Format(failures <-chan lint.Failure, _ lint.RulesConfig) (string, error) {
+	for failure := range failures {
+		fmt.Printf("%v: %s %s\n", failure.Position.Start, failure.Failure, "https://revive.run/r#"+failure.RuleName)
+	}
+	return "", nil
+}

formatter/stylish.go

@@ -22,11 +22,11 @@ func (f *Stylish) Name() string {
 
 func formatFailure(failure lint.Failure, severity lint.Severity) []string {
 	fString := color.CyanString(failure.Failure)
-	fName := color.RedString(failure.RuleName)
+	fName := color.RedString("https://revive.run/r#" + failure.RuleName)
 	lineColumn := failure.Position
 	pos := fmt.Sprintf("(%d, %d)", lineColumn.Start.Line, lineColumn.Start.Column)
 	if severity == lint.SeverityWarning {
-		fName = color.YellowString(failure.RuleName)
+		fName = color.YellowString("https://revive.run/r#" + failure.RuleName)
 	}
 	return []string{failure.GetFilename(), pos, fName, fString}
 }