internal/stdlib: fix Zip for master version

An error is fixed when creating the zipfile for std@master, which
prevented the module from being fetched. A test is also added.

For golang/go#44390

Change-Id: I279146aef10311822f47f16259a2223c879140c2
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/294831
Trust: Julie Qiu <[email protected]>
Run-TryBot: Julie Qiu <[email protected]>
Reviewed-by: Jonathan Amsterdam <[email protected]>

Author: julieqiu

internal/fetch/fetch_test.go

@@ -84,6 +84,8 @@ func TestFetchModule(t *testing.T) {
 		// Proxy only as stdlib is not accounted for in local mode
 		{name: "stdlib module", mod: moduleStd, proxyOnly: true},
 		// Proxy only as version is pre specified in local mode
+		{name: "master version of stdlib module", mod: moduleStdMaster, fetchVersion: "master", proxyOnly: true},
+		// Proxy only as version is pre specified in local mode
 		{name: "master version of module", mod: moduleMaster, fetchVersion: "master", proxyOnly: true},
 		// Proxy only as version is pre specified in local mode
 		{name: "latest version of module", mod: moduleLatest, fetchVersion: "latest", proxyOnly: true},

internal/fetch/fetchdata_test.go

@@ -642,6 +642,73 @@ var moduleAlternative = &testModule{
 	},
 }
 
+var moduleStdMaster = &testModule{
+	mod: &proxy.Module{
+		ModulePath: stdlib.ModulePath,
+		Version:    "master",
+		// No files necessary because the internal/stdlib package will read from
+		// internal/stdlib/testdata.
+	},
+	fr: &FetchResult{
+		RequestedVersion: "master",
+		ResolvedVersion:  stdlib.TestVersion,
+		Module: &internal.Module{
+			ModuleInfo: internal.ModuleInfo{
+				ModulePath: stdlib.ModulePath,
+				Version:    stdlib.TestVersion,
+				CommitTime: stdlib.TestCommitTime,
+				HasGoMod:   true,
+				SourceInfo: source.NewStdlibInfo("master"),
+			},
+			Units: []*internal.Unit{
+				{
+					UnitMeta: internal.UnitMeta{
+						Path:              "errors",
+						Name:              "errors",
+						IsRedistributable: true,
+						Version:           stdlib.TestVersion,
+						ModulePath:        stdlib.ModulePath,
+					},
+					Documentation: []*internal.Documentation{
+						{
+							GOOS:     internal.All,
+							GOARCH:   internal.All,
+							Synopsis: "Package errors implements functions to manipulate errors.",
+							API: []*internal.Symbol{
+								{
+									Name:     "New",
+									Synopsis: "func New(text string) error",
+									Section:  "Functions",
+									Kind:     "Function",
+									GOOS:     internal.All,
+									GOARCH:   internal.All,
+								},
+							},
+						},
+					},
+				},
+				{
+					UnitMeta: internal.UnitMeta{
+						Path:              "std",
+						IsRedistributable: true,
+						Version:           stdlib.TestVersion,
+						ModulePath:        "std",
+					},
+					Readme: &internal.Readme{Filepath: "README.md", Contents: "# The Go Programming Language\n"},
+				},
+			},
+		},
+		PackageVersionStates: []*internal.PackageVersionState{
+			{
+				PackagePath: "errors",
+				ModulePath:  "std",
+				Version:     stdlib.TestVersion,
+				Status:      200,
+			},
+		},
+	},
+}
+
 var moduleStd = &testModule{
 	mod: &proxy.Module{
 		ModulePath: stdlib.ModulePath,

internal/proxy/server.go

@@ -115,8 +115,12 @@ func (s *Server) AddModule(m *Module) {
 		s.handleLatest(m.ModulePath, fmt.Sprintf("/%s/@latest", m.ModulePath))
 		// TODO(https://golang.org/issue/39985): Add endpoint for handling
 		// master and main versions.
-		s.handleLatest(m.ModulePath, fmt.Sprintf("/%s/@v/master.info", m.ModulePath))
-		s.handleLatest(m.ModulePath, fmt.Sprintf("/%s/@v/main.info", m.ModulePath))
+		if m.Version != "master" {
+			s.handleLatest(m.ModulePath, fmt.Sprintf("/%s/@v/master.info", m.ModulePath))
+		}
+		if m.Version != "main" {
+			s.handleLatest(m.ModulePath, fmt.Sprintf("/%s/@v/main.info", m.ModulePath))
+		}
 	}
 	s.handleInfo(m.ModulePath, m.Version, m.NotCached)
 	s.handleMod(m)

internal/stdlib/stdlib.go

@@ -92,10 +92,9 @@ func TagForVersion(version string) (_ string, err error) {
 	defer derrors.Wrap(&err, "TagForVersion(%q)", version)
 
 	// Special case: master => master
-	if version == "master" {
-		return version, nil
+	if version == "master" || strings.HasPrefix(version, "v0.0.0") {
+		return "master", nil
 	}
-
 	// Special case: v1.0.0 => go1.
 	if version == "v1.0.0" {
 		return "go1", nil
@@ -110,7 +109,6 @@ func TagForVersion(version string) (_ string, err error) {
 	if patch == "0" {
 		versionWithoutPrerelease = strings.TrimSuffix(versionWithoutPrerelease, ".0")
 	}
-
 	goVersion = fmt.Sprintf("go%s", strings.TrimPrefix(versionWithoutPrerelease, "v"))
 	if prerelease != "" {
 		// Go prereleases look like  "beta1" instead of "beta.1".
@@ -174,7 +172,10 @@ const (
 var UseTestData = false
 
 // TestCommitTime is the time used for all commits when UseTestData is true.
-var TestCommitTime = time.Date(2019, 9, 4, 1, 2, 3, 0, time.UTC)
+var (
+	TestCommitTime = time.Date(2019, 9, 4, 1, 2, 3, 0, time.UTC)
+	TestVersion    = "v0.0.0-20190904010203-89fb59e2e920"
+)
 
 // getGoRepo returns a repo object for the Go repo at version.
 func getGoRepo(version string) (_ *git.Repository, err error) {
@@ -202,6 +203,9 @@ func getGoRepo(version string) (_ *git.Repository, err error) {
 // getTestGoRepo gets a Go repo for testing.
 func getTestGoRepo(version string) (_ *git.Repository, err error) {
 	defer derrors.Wrap(&err, "getTestGoRepo(%q)", version)
+	if strings.HasPrefix(version, "v0.0.0") {
+		version = "master"
+	}
 
 	fs := osfs.New(filepath.Join(testhelper.TestDataPath("testdata"), version))
 	repo, err := git.Init(memory.NewStorage(), fs)
@@ -262,7 +266,8 @@ func Versions() (_ []string, err error) {
 
 // Directory returns the directory of the standard library relative to the repo root.
 func Directory(version string) string {
-	if semver.Compare(version, "v1.4.0-beta.1") >= 0 || version == "master" {
+	if semver.Compare(version, "v1.4.0-beta.1") >= 0 ||
+		version == "master" || strings.HasPrefix(version, "v0.0.0") {
 		return "src"
 	}
 	// For versions older than v1.4.0-beta.1, the stdlib is in src/pkg.
@@ -322,6 +327,9 @@ func Zip(resolvedVersion string) (_ *zip.Reader, resolvedVersion2 string, commit
 	if err != nil {
 		return nil, "", time.Time{}, err
 	}
+	if resolvedVersion == "master" {
+		resolvedVersion = newPseudoVersion("v0.0.0", commit.Committer.When, commit.Hash)
+	}
 	root, err := repo.TreeObject(commit.TreeHash)
 	if err != nil {
 		return nil, "", time.Time{}, err
@@ -350,9 +358,6 @@ func Zip(resolvedVersion string) (_ *zip.Reader, resolvedVersion2 string, commit
 	if err != nil {
 		return nil, "", time.Time{}, err
 	}
-	if resolvedVersion == "master" {
-		resolvedVersion = newPseudoVersion("v0.0.0", commit.Committer.When, commit.Hash)
-	}
 	return zr, resolvedVersion, commit.Committer.When, nil
 }
 
@@ -368,7 +373,7 @@ func semanticVersion(requestedVersion string) (_ string, err error) {
 	defer derrors.Wrap(&err, "semanticVersion(%q)", requestedVersion)
 
 	if requestedVersion == "master" {
-		return requestedVersion, nil
+		return "master", nil
 	}
 
 	knownVersions, err := Versions()

internal/stdlib/stdlib_test.go

@@ -61,6 +61,11 @@ func TestTagForVersion(t *testing.T) {
 			version: "master",
 			want:    "master",
 		},
+		{
+			name:    "master version",
+			version: TestVersion,
+			want:    "master",
+		},
 		{
 			name:    "bad std semver",
 			version: "v1.x",
@@ -120,7 +125,7 @@ func TestMajorVersionForVersion(t *testing.T) {
 func TestZip(t *testing.T) {
 	UseTestData = true
 	defer func() { UseTestData = false }()
-	for _, resolvedVersion := range []string{"v1.14.6", "v1.12.5", "v1.3.2", "master"} {
+	for _, resolvedVersion := range []string{"v1.14.6", "v1.12.5", "v1.3.2", TestVersion} {
 		t.Run(resolvedVersion, func(t *testing.T) {
 			zr, gotResolvedVersion, gotTime, err := Zip(resolvedVersion)
 			if err != nil {
@@ -141,12 +146,12 @@ func TestZip(t *testing.T) {
 				"errors/errors.go":      true,
 				"errors/errors_test.go": true,
 			}
-			if semver.Compare(resolvedVersion, "v1.4.0") > 0 || resolvedVersion == "master" {
+			if semver.Compare(resolvedVersion, "v1.4.0") > 0 || resolvedVersion == TestVersion {
 				wantFiles["README.md"] = true
 			} else {
 				wantFiles["README"] = true
 			}
-			if semver.Compare(resolvedVersion, "v1.13.0") > 0 || resolvedVersion == "master" {
+			if semver.Compare(resolvedVersion, "v1.13.0") > 0 || resolvedVersion == TestVersion {
 				wantFiles["cmd/README.vendor"] = true
 			}