feat: add golicenser linter

.golangci.next.reference.yml

@@ -57,6 +57,7 @@ linters:
     - godot
     - godox
     - goheader
+    - golicenser
     - gomoddirectives
     - gomodguard
     - goprintffuncname
@@ -165,6 +166,7 @@ linters:
     - godot
     - godox
     - goheader
+    - golicenser
     - gomoddirectives
     - gomodguard
     - goprintffuncname
@@ -1279,6 +1281,79 @@ linters:
       # Default: ""
       template-path: /path/to/my/template.tmpl
 
+    golicenser:
+      # Regexp used to detect license/copyright headers.
+      # This will be used to detect the existence of a copyright header in a file.
+      # If the first comment in a Go source file does not match this, then a license header will be generated.
+      # For the license header to be updated, it must also match the header matcher.
+      # Default: "(?i)copyright"
+      copyright-header-matcher: "(?i)copyright"
+
+      header:
+        # The project author name used in the `author` template variable.
+        # Required value.
+        author: "My Name"
+        # Regexp used to match the project author (`author` variable).
+        # Default: regexp-escaped value of `author`.
+        author-regexp: "(My Name|Your Name)"
+        # Style of comment to use in license headers.
+        # More information: https://github.com/joshuasing/golicenser#comment-styles
+        # Valid options are: `line`, `block`.
+        # Default: "line"
+        comment-style: "line"
+        # License header template (using Go text/template: https://pkg.go.dev/text/template).
+        # More information: https://github.com/joshuasing/golicenser#templates
+        # Built-in variables:
+        # - `year`: Copyright year(s) for the file. The format is configurable with `year-mode`.
+        # - `author`: The copyright author (provided by `author`).
+        # - `filename`: The current filename.
+        # Custom variables can be provided in `variables` below.
+        # Required value.
+        template: |-
+          Copyright (c) {{.year}} {{.author}}. All rights reserved.
+          Use of this source code is governed by a BSD-style
+          license that can be found in the LICENSE file.
+        # Path to file containing license header template.
+        # This is an alternative to `template`, and `template` will take priority if set.
+        # By default, if a path is relative, it is relative to the directory where the golangci-lint command is executed.
+        # The placeholder '${base-path}' is substituted with a path relative to the mode defined with `run.relative-path-mode`.
+        # The placeholder '${config-path}' is substituted with a path relative to the configuration file.
+        # Default: ""
+        template-path: /path/to/my/template.tmpl
+        # License header match regexp.
+        # More information: https://github.com/joshuasing/golicenser#matcher
+        # Matched headers will be updated or replaced by the header template.
+        # Default: regexp-escaped value of `template`.
+        matcher: |-
+          Copyright \(c\) {{.year}} {{.author}}.(\s*All rights reserved.)?
+          Use of this source code is governed by a BSD-style
+          license that can be found in the LICENSE file.
+        # Enable to regexp-escape the header matcher.
+        # Useful if you want to provide a license header instead of regexp expression.
+        # Default: false
+        matcher-escape: false
+        # Variables to provide to the header template.
+        # Due to a limitation of Viper, the configuration loader used by golangci-lint, variable names will always be
+        # provided as lowercase to the template.
+        # Default: {}
+        variables:
+          email:
+            regexp: "(.+)@mycompany\\.com"
+          project-name:
+            value: "My project"
+        # Copyright year formatting mode.
+        # More information: https://github.com/joshuasing/golicenser#year-modes
+        # Available year modes are:
+        # - `preserve`: Current year in new headers, existing year in updated headers.
+        # - `preserve-this-year-range`: Current year in new headers, existing year to current year in updated headers.
+        # - `preserve-modified-range`: Last modified year in new headers, existing year to last modified year in updated headers.
+        # - `this-year`: Current year.
+        # - `last-modified`: File last modified year.
+        # - `git-range`: Git history creation year to last modified year (e.g. `2022-2025`)
+        # - `git-modified-list`: List of all modified years from Git history (e.g. `2022, 2024, 2025`)
+        # Default: "preserve"
+        year-mode: "git-range"
+
     gomoddirectives:
       # Allow local `replace` directives.
       # Default: false

go.mod

@@ -60,6 +60,7 @@ require (
 	github.com/jgautheron/goconst v1.8.1
 	github.com/jingyugao/rowserrcheck v1.1.1
 	github.com/jjti/go-spancheck v0.6.4
+	github.com/joshuasing/golicenser v0.3.1
 	github.com/julz/importas v0.2.0
 	github.com/karamaru-alpha/copyloopvar v1.2.1
 	github.com/kisielk/errcheck v1.9.0
@@ -141,6 +142,7 @@ require (
 	github.com/Masterminds/semver/v3 v3.3.1 // indirect
 	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/bmatcuk/doublestar/v4 v4.8.1 // indirect
 	github.com/ccojocar/zxcvbn-go v1.0.2 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/charmbracelet/colorprofile v0.2.3-0.20250311203215-f60798e515dc // indirect

jsonschema/golangci.next.jsonschema.json

@@ -757,6 +757,7 @@
             "godox",
             "err113",
             "goheader",
+            "golicenser",
             "gomoddirectives",
             "gomodguard",
             "goprintffuncname",
@@ -1935,6 +1936,96 @@
             { "required": ["template-path"] }
           ]
         },
+        "golicenserSettings": {
+          "type": "object",
+          "additionalProperties": false,
+          "properties": {
+            "copyright-header-matcher": {
+              "description": "Regexp used to detect license/copyright headers. This is used to detect the existence of any copyright header in a file.",
+              "type": "string",
+              "default": "(?i)copyright"
+            },
+            "header": {
+              "description": "License header settings.",
+              "type": "object",
+              "properties": {
+                "template": {
+                  "description": "License header template (using Go text/template)\nhttps://github.com/joshuasing/golicenser#templates",
+                  "type": "string",
+                  "examples": [
+                    "Copyright (c) {{.year}} {{.author}}. All rights reserved.\nUse of this source code is governed by a BSD-style\nlicense that can be found in the LICENSE file."
+                  ]
+                },
+                "template-path": {
+                  "description": "Path to file containing license header template",
+                  "type": "string",
+                  "examples": [
+                    "license.txt",
+                    "license-header.txt"
+                  ]
+                },
+                "matcher": {
+                  "description": "License header matcher regexp\nhttps://github.com/joshuasing/golicenser#matcher",
+                  "type": "string",
+                  "examples": [
+                    "Copyright \\(c\\) {{.year}} {{.author}}(.|\\s<[email protected]>)"
+                  ]
+                },
+                "matcher-escape": {
+                  "description": "Enable to regexp-escape the header matcher. Useful for providing a license template instead of regexp.",
+                  "type": "boolean",
+                  "default": false
+                },
+                "author": {
+                  "description": "Project author name (used in the `author` template variable).",
+                  "type": "string"
+                },
+                "author-regexp": {
+                  "description": "Regexp used to match the project author (`author` variable)",
+                  "type": "string"
+                },
+                "variables": {
+                  "description": "Custom variables to provide to the header template\nNote: Due to a limitation of Viper, the configuration loader used by golangci-lint, variable names will always be provided as lowercase to the template.",
+                  "type": "object",
+                  "additionalProperties": false,
+                  "patternProperties": {
+                    "^[a-z\\-]+$": {
+                      "type": "object",
+                      "additionalProperties": false,
+                      "properties": {
+                        "value": {
+                          "description": "Variable value",
+                          "type": "string"
+                        },
+                        "regexp": {
+                          "description": "Variable matcher regexp",
+                          "type": "string"
+                        }
+                      }
+                    }
+                  }
+                },
+                "year-mode": {
+                  "description": "Copyright year formatting mode.\nhttps://github.com/joshuasing/golicenser#year-modes",
+                  "type": "string",
+                  "enum": ["preserve", "preserve-this-year-range", "preserve-modified-range", "this-year", "last-modified", "git-range", "git-modified-list"],
+                  "default": "preserve"
+                },
+                "comment-style": {
+                  "description": "Style of comment to use in license headers.\nhttps://github.com/joshuasing/golicenser#comment-styles",
+                  "type": "string",
+                  "enum": ["line", "block"],
+                  "default": "line"
+                }
+              },
+              "oneOf": [
+                { "required": ["template", "author"] },
+                { "required": ["template-path", "author"] }
+              ]
+            }
+          },
+          "required": ["header"]
+        },
         "goimportsSettings": {
           "type": "object",
           "additionalProperties": false,
@@ -4399,6 +4490,9 @@
             "goheader": {
               "$ref": "#/definitions/settings/definitions/goheaderSettings"
             },
+            "golicenser": {
+              "$ref": "#/definitions/settings/definitions/golicenserSettings"
+            },
             "gomoddirectives": {
               "$ref": "#/definitions/settings/definitions/gomoddirectivesSettings"
             },

pkg/config/linters_settings.go

@@ -232,6 +232,7 @@ type LintersSettings struct {
 	Godot           GodotSettings           `mapstructure:"godot"`
 	Godox           GodoxSettings           `mapstructure:"godox"`
 	Goheader        GoHeaderSettings        `mapstructure:"goheader"`
+	Golicenser      GoLicenserSettings      `mapstructure:"golicenser"`
 	GoModDirectives GoModDirectivesSettings `mapstructure:"gomoddirectives"`
 	Gomodguard      GoModGuardSettings      `mapstructure:"gomodguard"`
 	Gosec           GoSecSettings           `mapstructure:"gosec"`
@@ -510,6 +511,28 @@ type GoHeaderSettings struct {
 	TemplatePath string                       `mapstructure:"template-path"`
 }
 
+type GoLicenserSettings struct {
+	Header                 GoLicenserHeaderSettings `mapstructure:"header"`
+	CopyrightHeaderMatcher string                   `mapstructure:"copyright-header-matcher"`
+}
+
+type GoLicenserHeaderSettings struct {
+	Template      string                   `mapstructure:"template"`
+	TemplatePath  string                   `mapstructure:"template-path"`
+	Matcher       string                   `mapstructure:"matcher"`
+	MatcherEscape bool                     `mapstructure:"matcher-escape"`
+	Author        string                   `mapstructure:"author"`
+	AuthorRegexp  string                   `mapstructure:"author-regexp"`
+	Variables     map[string]GoLicenserVar `mapstructure:"variables"`
+	YearMode      string                   `mapstructure:"year-mode"`
+	CommentStyle  string                   `mapstructure:"comment-style"`
+}
+
+type GoLicenserVar struct {
+	Value  string `mapstructure:"value"`
+	Regexp string `mapstructure:"regexp"`
+}
+
 type GoModDirectivesSettings struct {
 	ReplaceAllowList          []string `mapstructure:"replace-allow-list"`
 	ReplaceLocal              bool     `mapstructure:"replace-local"`

pkg/golinters/golicenser/golicenser.go

@@ -0,0 +1,94 @@
+package golicenser
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/joshuasing/golicenser"
+	"golang.org/x/tools/go/analysis"
+
+	"github.com/golangci/golangci-lint/v2/pkg/config"
+	"github.com/golangci/golangci-lint/v2/pkg/goanalysis"
+	"github.com/golangci/golangci-lint/v2/pkg/golinters/internal"
+)
+
+const linterName = "golicenser"
+
+func New(settings *config.GoLicenserSettings, replacer *strings.Replacer) *goanalysis.Linter {
+	conf, err := createConfig(settings, replacer)
+	if err != nil {
+		internal.LinterLogger.Fatalf("%s: parse year mode: %v", linterName, err)
+	}
+
+	analyzer, err := golicenser.NewAnalyzer(conf)
+	if err != nil {
+		internal.LinterLogger.Fatalf("%s: create analyzer: %v", linterName, err)
+	}
+
+	return goanalysis.NewLinter(
+		linterName,
+		"Powerful license header linter",
+		[]*analysis.Analyzer{analyzer},
+		nil,
+	).WithLoadMode(goanalysis.LoadModeSyntax)
+}
+
+func createConfig(settings *config.GoLicenserSettings, replacer *strings.Replacer) (golicenser.Config, error) {
+	if settings == nil {
+		return golicenser.Config{}, nil
+	}
+
+	header := golicenser.HeaderOpts{
+		Matcher:       settings.Header.Matcher,
+		MatcherEscape: settings.Header.MatcherEscape,
+		Author:        settings.Header.Author,
+		AuthorRegexp:  settings.Header.AuthorRegexp,
+		Template:      settings.Header.Template,
+		Variables:     make(map[string]*golicenser.Var, len(settings.Header.Variables)),
+	}
+
+	// Template from config takes priority over template from 'template-path'.
+	if header.Template == "" && settings.Header.TemplatePath != "" {
+		b, err := os.ReadFile(replacer.Replace(settings.Header.TemplatePath))
+		if err != nil {
+			return golicenser.Config{}, fmt.Errorf("read the template file: %w", err)
+		}
+
+		// Use template from a file (trim newline from the end of file)
+		header.Template = strings.TrimSuffix(strings.TrimSuffix(string(b), "\n"), "\r")
+	}
+
+	var err error
+	if settings.Header.YearMode != "" {
+		header.YearMode, err = golicenser.ParseYearMode(settings.Header.YearMode)
+		if err != nil {
+			return golicenser.Config{}, fmt.Errorf("parse year mode: %w", err)
+		}
+	}
+
+	if settings.Header.CommentStyle != "" {
+		header.CommentStyle, err = golicenser.ParseCommentStyle(settings.Header.CommentStyle)
+		if err != nil {
+			return golicenser.Config{}, fmt.Errorf("parse comment style: %w", err)
+		}
+	}
+
+	for k, v := range settings.Header.Variables {
+		header.Variables[k] = &golicenser.Var{
+			Value:  v.Value,
+			Regexp: v.Regexp,
+		}
+	}
+
+	return golicenser.Config{
+		Header:                 header,
+		CopyrightHeaderMatcher: settings.CopyrightHeaderMatcher,
+
+		// NOTE(ldez): not wanted for now.
+		// And an empty slice is used because of a wrong default inside the linter.
+		Exclude: []string{},
+		// NOTE(ldez): golangci-lint already handles concurrency.
+		MaxConcurrent: 1,
+	}, nil
+}

pkg/golinters/golicenser/golicenser_integration_test.go

@@ -0,0 +1,19 @@
+package golicenser
+
+import (
+	"testing"
+
+	"github.com/golangci/golangci-lint/v2/test/testshared/integration"
+)
+
+func TestFromTestdata(t *testing.T) {
+	integration.RunTestdata(t)
+}
+
+func TestFix(t *testing.T) {
+	integration.RunFix(t)
+}
+
+func TestFixPathPrefix(t *testing.T) {
+	integration.RunFixPathPrefix(t)
+}