cmd/go: move repository resolution from internal/get to internal/vcs

This is a refactoring intended to break the dependency from
internal/modfetch to internal/get. No change in functionality is intended.

Change-Id: If51aba7139cc0b62ecc9ba454c055c99e8f36f0f
Reviewed-on: https://go-review.googlesource.com/c/go/+/254364
Run-TryBot: Jay Conrod <[email protected]>
Reviewed-by: Bryan C. Mills <[email protected]>
Reviewed-by: Michael Matloob <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>

Author: Jay Conrod

src/cmd/go/internal/get/get.go

@@ -18,6 +18,7 @@ import (
 	"cmd/go/internal/load"
 	"cmd/go/internal/search"
 	"cmd/go/internal/str"
+	"cmd/go/internal/vcs"
 	"cmd/go/internal/web"
 	"cmd/go/internal/work"
 
@@ -406,7 +407,7 @@ func download(arg string, parent *load.Package, stk *load.ImportStack, mode int)
 // to make the first copy of or update a copy of the given package.
 func downloadPackage(p *load.Package) error {
 	var (
-		vcs            *vcsCmd
+		vcsCmd         *vcs.Cmd
 		repo, rootPath string
 		err            error
 		blindRepo      bool // set if the repo has unusual configuration
@@ -435,27 +436,27 @@ func downloadPackage(p *load.Package) error {
 
 	if p.Internal.Build.SrcRoot != "" {
 		// Directory exists. Look for checkout along path to src.
-		vcs, rootPath, err = vcsFromDir(p.Dir, p.Internal.Build.SrcRoot)
+		vcsCmd, rootPath, err = vcs.FromDir(p.Dir, p.Internal.Build.SrcRoot)
 		if err != nil {
 			return err
 		}
 		repo = "<local>" // should be unused; make distinctive
 
 		// Double-check where it came from.
-		if *getU && vcs.remoteRepo != nil {
+		if *getU && vcsCmd.RemoteRepo != nil {
 			dir := filepath.Join(p.Internal.Build.SrcRoot, filepath.FromSlash(rootPath))
-			remote, err := vcs.remoteRepo(vcs, dir)
+			remote, err := vcsCmd.RemoteRepo(vcsCmd, dir)
 			if err != nil {
 				// Proceed anyway. The package is present; we likely just don't understand
 				// the repo configuration (e.g. unusual remote protocol).
 				blindRepo = true
 			}
 			repo = remote
 			if !*getF && err == nil {
-				if rr, err := RepoRootForImportPath(importPrefix, IgnoreMod, security); err == nil {
+				if rr, err := vcs.RepoRootForImportPath(importPrefix, vcs.IgnoreMod, security); err == nil {
 					repo := rr.Repo
-					if rr.vcs.resolveRepo != nil {
-						resolved, err := rr.vcs.resolveRepo(rr.vcs, dir, repo)
+					if rr.VCS.ResolveRepo != nil {
+						resolved, err := rr.VCS.ResolveRepo(rr.VCS, dir, repo)
 						if err == nil {
 							repo = resolved
 						}
@@ -469,13 +470,13 @@ func downloadPackage(p *load.Package) error {
 	} else {
 		// Analyze the import path to determine the version control system,
 		// repository, and the import path for the root of the repository.
-		rr, err := RepoRootForImportPath(importPrefix, IgnoreMod, security)
+		rr, err := vcs.RepoRootForImportPath(importPrefix, vcs.IgnoreMod, security)
 		if err != nil {
 			return err
 		}
-		vcs, repo, rootPath = rr.vcs, rr.Repo, rr.Root
+		vcsCmd, repo, rootPath = rr.VCS, rr.Repo, rr.Root
 	}
-	if !blindRepo && !vcs.isSecure(repo) && security != web.Insecure {
+	if !blindRepo && !vcsCmd.IsSecure(repo) && security != web.Insecure {
 		return fmt.Errorf("cannot download, %v uses insecure protocol", repo)
 	}
 
@@ -498,7 +499,7 @@ func downloadPackage(p *load.Package) error {
 	}
 	root := filepath.Join(p.Internal.Build.SrcRoot, filepath.FromSlash(rootPath))
 
-	if err := checkNestedVCS(vcs, root, p.Internal.Build.SrcRoot); err != nil {
+	if err := vcs.CheckNested(vcsCmd, root, p.Internal.Build.SrcRoot); err != nil {
 		return err
 	}
 
@@ -514,7 +515,7 @@ func downloadPackage(p *load.Package) error {
 
 	// Check that this is an appropriate place for the repo to be checked out.
 	// The target directory must either not exist or have a repo checked out already.
-	meta := filepath.Join(root, "."+vcs.cmd)
+	meta := filepath.Join(root, "."+vcsCmd.Cmd)
 	if _, err := os.Stat(meta); err != nil {
 		// Metadata file or directory does not exist. Prepare to checkout new copy.
 		// Some version control tools require the target directory not to exist.
@@ -535,12 +536,12 @@ func downloadPackage(p *load.Package) error {
 			fmt.Fprintf(os.Stderr, "created GOPATH=%s; see 'go help gopath'\n", p.Internal.Build.Root)
 		}
 
-		if err = vcs.create(root, repo); err != nil {
+		if err = vcsCmd.Create(root, repo); err != nil {
 			return err
 		}
 	} else {
 		// Metadata directory does exist; download incremental updates.
-		if err = vcs.download(root); err != nil {
+		if err = vcsCmd.Download(root); err != nil {
 			return err
 		}
 	}
@@ -549,20 +550,20 @@ func downloadPackage(p *load.Package) error {
 		// Do not show tag sync in -n; it's noise more than anything,
 		// and since we're not running commands, no tag will be found.
 		// But avoid printing nothing.
-		fmt.Fprintf(os.Stderr, "# cd %s; %s sync/update\n", root, vcs.cmd)
+		fmt.Fprintf(os.Stderr, "# cd %s; %s sync/update\n", root, vcsCmd.Cmd)
 		return nil
 	}
 
 	// Select and sync to appropriate version of the repository.
-	tags, err := vcs.tags(root)
+	tags, err := vcsCmd.Tags(root)
 	if err != nil {
 		return err
 	}
 	vers := runtime.Version()
 	if i := strings.Index(vers, " "); i >= 0 {
 		vers = vers[:i]
 	}
-	if err := vcs.tagSync(root, selectTag(vers, tags)); err != nil {
+	if err := vcsCmd.TagSync(root, selectTag(vers, tags)); err != nil {
 		return err
 	}
 

src/cmd/go/internal/modfetch/repo.go

@@ -13,9 +13,9 @@ import (
 	"time"
 
 	"cmd/go/internal/cfg"
-	"cmd/go/internal/get"
 	"cmd/go/internal/modfetch/codehost"
 	"cmd/go/internal/par"
+	"cmd/go/internal/vcs"
 	web "cmd/go/internal/web"
 
 	"golang.org/x/mod/module"
@@ -261,13 +261,13 @@ func lookupDirect(path string) (Repo, error) {
 	if allowInsecure(path) {
 		security = web.Insecure
 	}
-	rr, err := get.RepoRootForImportPath(path, get.PreferMod, security)
+	rr, err := vcs.RepoRootForImportPath(path, vcs.PreferMod, security)
 	if err != nil {
 		// We don't know where to find code for a module with this path.
 		return nil, notExistError{err: err}
 	}
 
-	if rr.VCS == "mod" {
+	if rr.VCS.Name == "mod" {
 		// Fetch module from proxy with base URL rr.Repo.
 		return newProxyRepo(rr.Repo, path)
 	}
@@ -279,8 +279,8 @@ func lookupDirect(path string) (Repo, error) {
 	return newCodeRepo(code, rr.Root, path)
 }
 
-func lookupCodeRepo(rr *get.RepoRoot) (codehost.Repo, error) {
-	code, err := codehost.NewRepo(rr.VCS, rr.Repo)
+func lookupCodeRepo(rr *vcs.RepoRoot) (codehost.Repo, error) {
+	code, err := codehost.NewRepo(rr.VCS.Cmd, rr.Repo)
 	if err != nil {
 		if _, ok := err.(*codehost.VCSError); ok {
 			return nil, err
@@ -306,7 +306,7 @@ func ImportRepoRev(path, rev string) (Repo, *RevInfo, error) {
 	if allowInsecure(path) {
 		security = web.Insecure
 	}
-	rr, err := get.RepoRootForImportPath(path, get.IgnoreMod, security)
+	rr, err := vcs.RepoRootForImportPath(path, vcs.IgnoreMod, security)
 	if err != nil {
 		return nil, nil, err
 	}

src/cmd/go/internal/str/str_test.go

@@ -0,0 +1,27 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package str
+
+import "testing"
+
+var foldDupTests = []struct {
+	list   []string
+	f1, f2 string
+}{
+	{StringList("math/rand", "math/big"), "", ""},
+	{StringList("math", "strings"), "", ""},
+	{StringList("strings"), "", ""},
+	{StringList("strings", "strings"), "strings", "strings"},
+	{StringList("Rand", "rand", "math", "math/rand", "math/Rand"), "Rand", "rand"},
+}
+
+func TestFoldDup(t *testing.T) {
+	for _, tt := range foldDupTests {
+		f1, f2 := FoldDup(tt.list)
+		if f1 != tt.f1 || f2 != tt.f2 {
+			t.Errorf("foldDup(%q) = %q, %q, want %q, %q", tt.list, f1, f2, tt.f1, tt.f2)
+		}
+	}
+}

src/cmd/go/internal/get/discovery.go renamed to src/cmd/go/internal/vcs/discovery.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package get
+package vcs
 
 import (
 	"encoding/xml"

src/cmd/go/internal/get/pkg_test.go renamed to src/cmd/go/internal/vcs/discovery_test.go

@@ -2,35 +2,14 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package get
+package vcs
 
 import (
-	"cmd/go/internal/str"
 	"reflect"
 	"strings"
 	"testing"
 )
 
-var foldDupTests = []struct {
-	list   []string
-	f1, f2 string
-}{
-	{str.StringList("math/rand", "math/big"), "", ""},
-	{str.StringList("math", "strings"), "", ""},
-	{str.StringList("strings"), "", ""},
-	{str.StringList("strings", "strings"), "strings", "strings"},
-	{str.StringList("Rand", "rand", "math", "math/rand", "math/Rand"), "Rand", "rand"},
-}
-
-func TestFoldDup(t *testing.T) {
-	for _, tt := range foldDupTests {
-		f1, f2 := str.FoldDup(tt.list)
-		if f1 != tt.f1 || f2 != tt.f2 {
-			t.Errorf("foldDup(%q) = %q, %q, want %q, %q", tt.list, f1, f2, tt.f1, tt.f2)
-		}
-	}
-}
-
 var parseMetaGoImportsTests = []struct {
 	in  string
 	mod ModuleMode