refactor: drop golang.org/x/tools/go/vcs dependency (elastic#40016)

* refactor: drop golang.org/x/tools/go/vcs dependency

golang.org/x/tools/go/vcs is deprecated and was initially developed before module
support was added.
However we are not using vcs.Cmd at all, we're using one method to retrieve the
vcs being used. As a quick fix, we can copy the method since it's short and
self-contained and we don't need the whole package.

* notice: regenerate notice file

* lint: replace deprecated ioutil package

* lint: preallocate srcDirs

* lint: replace deprecated strings.Title

* lint: more obvious preallocation to solve linting errors

* docs: add comment about fromDir origin

* fix: use cases.Title correctly to resolve template errors

* fix: run caser with NoLower option to maintain the same behaviour

NOTICE.txt

@@ -24826,43 +24826,6 @@ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
---------------------------------------------------------------------------------
-Dependency : golang.org/x/tools/go/vcs
-Version: v0.1.0-deprecated
-Licence type (autodetected): BSD-3-Clause
---------------------------------------------------------------------------------
-
-Contents of probable licence file $GOMODCACHE/golang.org/x/tools/go/[email protected]/LICENSE:
-
-Copyright (c) 2009 The Go Authors. All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are
-met:
-
-   * Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
-   * Redistributions in binary form must reproduce the above
-copyright notice, this list of conditions and the following disclaimer
-in the documentation and/or other materials provided with the
-distribution.
-   * Neither the name of Google Inc. nor the names of its
-contributors may be used to endorse or promote products derived from
-this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
 --------------------------------------------------------------------------------
 Dependency : google.golang.org/api
 Version: v0.128.0

dev-tools/mage/settings.go

@@ -21,7 +21,6 @@ import (
 	"errors"
 	"fmt"
 	"go/build"
-	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
@@ -32,7 +31,8 @@ import (
 	"time"
 
 	"github.com/magefile/mage/sh"
-	"golang.org/x/tools/go/vcs"
+	"golang.org/x/text/cases"
+	"golang.org/x/text/language"
 
 	"github.com/elastic/beats/v7/dev-tools/mage/gotool"
 )
@@ -85,6 +85,8 @@ var (
 	versionQualified bool
 	versionQualifier string
 
+	caser = cases.Title(language.English, cases.NoLower)
+
 	FuncMap = map[string]interface{}{
 		"beat_doc_branch":   BeatDocBranch,
 		"beat_version":      BeatQualifiedVersion,
@@ -94,7 +96,7 @@ var (
 		"elastic_beats_dir": ElasticBeatsDir,
 		"go_version":        GoVersion,
 		"repo":              GetProjectRepoInfo,
-		"title":             strings.Title,
+		"title":             caser.String,
 		"tolower":           strings.ToLower,
 		"contains":          strings.Contains,
 	}
@@ -491,7 +493,7 @@ func (s *BuildVariableSources) GetBeatVersion() (string, error) {
 		return "", err
 	}
 
-	data, err := ioutil.ReadFile(file)
+	data, err := os.ReadFile(file)
 	if err != nil {
 		return "", fmt.Errorf("failed to read beat version file=%v: %w", file, err)
 	}
@@ -509,7 +511,7 @@ func (s *BuildVariableSources) GetGoVersion() (string, error) {
 		return "", err
 	}
 
-	data, err := ioutil.ReadFile(file)
+	data, err := os.ReadFile(file)
 	if err != nil {
 		return "", fmt.Errorf("failed to read go version file=%v: %w", file, err)
 	}
@@ -527,7 +529,7 @@ func (s *BuildVariableSources) GetDocBranch() (string, error) {
 		return "", err
 	}
 
-	data, err := ioutil.ReadFile(file)
+	data, err := os.ReadFile(file)
 	if err != nil {
 		return "", fmt.Errorf("failed to read doc branch file=%v: %w", file, err)
 	}
@@ -688,7 +690,7 @@ func getProjectRepoInfoUnderGopath() (*ProjectRepoInfo, error) {
 	}
 
 	for _, srcDir := range srcDirs {
-		_, root, err := vcs.FromDir(cwd, srcDir)
+		root, err := fromDir(cwd, srcDir)
 		if err != nil {
 			// Try the next gopath.
 			errs = append(errs, err.Error())
@@ -721,6 +723,66 @@ func getProjectRepoInfoUnderGopath() (*ProjectRepoInfo, error) {
 	}, nil
 }
 
+var vcsList = []string{
+	"hg",
+	"git",
+	"svn",
+	"bzr",
+}
+
+// this method has been adapted from vcs.FromDir from golang.org/x/tools/go/vcs
+//
+// the body of the method was kept as is but the extra return value
+// has been removed since it was unused.
+func fromDir(dir, srcRoot string) (root string, err error) {
+	// Clean and double-check that dir is in (a subdirectory of) srcRoot.
+	dir = filepath.Clean(dir)
+	srcRoot = filepath.Clean(srcRoot)
+	if len(dir) <= len(srcRoot) || dir[len(srcRoot)] != filepath.Separator {
+		return "", fmt.Errorf("directory %q is outside source root %q", dir, srcRoot)
+	}
+
+	var vcsRet string
+	var rootRet string
+
+	origDir := dir
+	for len(dir) > len(srcRoot) {
+		for _, vcs := range vcsList {
+			if _, err := os.Stat(filepath.Join(dir, "."+vcs)); err == nil {
+				root := filepath.ToSlash(dir[len(srcRoot)+1:])
+				// Record first VCS we find, but keep looking,
+				// to detect mistakes like one kind of VCS inside another.
+				if vcsRet == "" {
+					vcsRet = vcs
+					rootRet = root
+					continue
+				}
+				// Allow .git inside .git, which can arise due to submodules.
+				if vcsRet == vcs && vcs == "git" {
+					continue
+				}
+				// Otherwise, we have one VCS inside a different VCS.
+				return "", fmt.Errorf("directory %q uses %s, but parent %q uses %s",
+					filepath.Join(srcRoot, rootRet), vcsRet, filepath.Join(srcRoot, root), vcs)
+			}
+		}
+
+		// Move to parent.
+		ndir := filepath.Dir(dir)
+		if len(ndir) >= len(dir) {
+			// Shouldn't happen, but just in case, stop.
+			break
+		}
+		dir = ndir
+	}
+
+	if vcsRet != "" {
+		return rootRet, nil
+	}
+
+	return "", fmt.Errorf("directory %q is not using a known version control system", origDir)
+}
+
 func extractCanonicalRootImportPath(rootImportPath string) string {
 	// In order to be compatible with go modules, the root import
 	// path of any module at major version v2 or higher must include
@@ -734,12 +796,14 @@ func extractCanonicalRootImportPath(rootImportPath string) string {
 }
 
 func listSrcGOPATHs() ([]string, error) {
+	gopaths := filepath.SplitList(build.Default.GOPATH)
+
 	var (
-		cwd     = CWD()
-		errs    []string
-		srcDirs []string
+		cwd  = CWD()
+		errs []string
 	)
-	for _, gopath := range filepath.SplitList(build.Default.GOPATH) {
+	srcDirs := make([]string, 0, len(gopaths))
+	for _, gopath := range gopaths {
 		gopath = filepath.Clean(gopath)
 
 		if !strings.HasPrefix(cwd, gopath) {

go.mod

@@ -226,7 +226,6 @@ require (
 	go.elastic.co/apm/module/apmhttp/v2 v2.6.0
 	go.elastic.co/apm/v2 v2.6.0
 	go.mongodb.org/mongo-driver v1.5.1
-	golang.org/x/tools/go/vcs v0.1.0-deprecated
 	google.golang.org/genproto/googleapis/api v0.0.0-20230913181813-007df8e322eb
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0
 )

go.sum

@@ -2223,8 +2223,6 @@ golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
 golang.org/x/tools v0.13.0/go.mod h1:HvlwmtVNQAhOuCjW7xxvovg8wbNq7LwfXh/k7wXUl58=
 golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d h1:vU5i/LfpvrRCpgM/VPfJLg5KjxD3E+hfT1SH+d9zLwg=
 golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d/go.mod h1:aiJjzUbINMkxbQROHiO6hDPo2LHcIPhhQsa9DLh0yGk=
-golang.org/x/tools/go/vcs v0.1.0-deprecated h1:cOIJqWBl99H1dH5LWizPa+0ImeeJq3t3cJjaeOWUAL4=
-golang.org/x/tools/go/vcs v0.1.0-deprecated/go.mod h1:zUrvATBAvEI9535oC0yWYsLsHIV4Z7g63sNPVMtuBy8=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=