whatcanGOwrong

go/pkg/mod/golang.org/x/telemetry@v0.0.0-20240829154258-f29ab539cc98/internal/proxy/proxy.go

@@ -0,0 +1,144 @@
+// Copyright 2023 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 proxy provides functions for writing module data to a directory
+// in proxy format, so that it can be used as a module proxy by setting
+// GOPROXY="file://<dir>".
+// This is copied from golang.org/x/tools/gopls/internal/{proxydir,proxy}.
+package proxy
+
+import (
+	"archive/zip"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"golang.org/x/mod/module"
+)
+
+// WriteProxy creates a new proxy file tree using the provided content,
+// and returns its URL.
+func WriteProxy(tmpdir string, files map[string][]byte) (string, error) {
+	type moduleVersion struct {
+		modulePath, version string
+	}
+	// Transform into the format expected by the proxydir package.
+	filesByModule := make(map[moduleVersion]map[string][]byte)
+	for name, data := range files {
+		modulePath, version, suffix := splitModuleVersionPath(name)
+		mv := moduleVersion{modulePath, version}
+		if _, ok := filesByModule[mv]; !ok {
+			filesByModule[mv] = make(map[string][]byte)
+		}
+		filesByModule[mv][suffix] = data
+	}
+	for mv, files := range filesByModule {
+		if err := writeModuleVersion(tmpdir, mv.modulePath, mv.version, files); err != nil {
+			return "", fmt.Errorf("error writing %s@%s: %v", mv.modulePath, mv.version, err)
+		}
+	}
+	return toURL(tmpdir), nil
+}
+
+// splitModuleVersionPath extracts module information from files stored in the
+// directory structure modulePath@version/suffix.
+// For example:
+//
+//	splitModuleVersionPath("mod.com@v1.2.3/package") = ("mod.com", "v1.2.3", "package")
+func splitModuleVersionPath(path string) (modulePath, version, suffix string) {
+	parts := strings.Split(path, "/")
+	var modulePathParts []string
+	for i, p := range parts {
+		if strings.Contains(p, "@") {
+			mv := strings.SplitN(p, "@", 2)
+			modulePathParts = append(modulePathParts, mv[0])
+			return strings.Join(modulePathParts, "/"), mv[1], strings.Join(parts[i+1:], "/")
+		}
+		modulePathParts = append(modulePathParts, p)
+	}
+	// Default behavior: this is just a module path.
+	return path, "", ""
+}
+
+// writeModuleVersion creates a directory in the proxy dir for a module.
+func writeModuleVersion(rootDir, mod, ver string, files map[string][]byte) (rerr error) {
+	dir := filepath.Join(rootDir, mod, "@v")
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return err
+	}
+
+	// The go command checks for versions by looking at the "list" file.  Since
+	// we are supporting multiple versions, create this file if it does not exist
+	// or append the version number to the preexisting file.
+
+	f, err := os.OpenFile(filepath.Join(dir, "list"), os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		return err
+	}
+	defer checkClose("list file", f, &rerr)
+	if _, err := f.WriteString(ver + "\n"); err != nil {
+		return err
+	}
+
+	// Serve the go.mod file on the <version>.mod url, if it exists. Otherwise,
+	// serve a stub.
+	modContents, ok := files["go.mod"]
+	if !ok {
+		modContents = []byte("module " + mod)
+	}
+	if err := os.WriteFile(filepath.Join(dir, ver+".mod"), modContents, 0644); err != nil {
+		return err
+	}
+
+	// info file, just the bare bones.
+	infoContents := []byte(fmt.Sprintf(`{"Version": "%v", "Time":"2017-12-14T13:08:43Z"}`, ver))
+	if err := os.WriteFile(filepath.Join(dir, ver+".info"), infoContents, 0644); err != nil {
+		return err
+	}
+
+	// zip of all the source files.
+	f, err = os.OpenFile(filepath.Join(dir, ver+".zip"), os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		return err
+	}
+	defer checkClose("zip file", f, &rerr)
+	z := zip.NewWriter(f)
+	defer checkClose("zip writer", z, &rerr)
+	for name, contents := range files {
+		zf, err := z.Create(mod + "@" + ver + "/" + name)
+		if err != nil {
+			return err
+		}
+		if _, err := zf.Write(contents); err != nil {
+			return err
+		}
+	}
+
+	// Populate the /module/path/@latest that is used by @latest query.
+	if module.IsPseudoVersion(ver) {
+		latestFile := filepath.Join(rootDir, mod, "@latest")
+		if err := os.WriteFile(latestFile, infoContents, 0644); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func checkClose(name string, closer io.Closer, err *error) {
+	if cerr := closer.Close(); cerr != nil && *err == nil {
+		*err = fmt.Errorf("closing %s: %v", name, cerr)
+	}
+}
+
+// toURL returns the file uri for a proxy directory.
+func toURL(dir string) string {
+	// file URLs on Windows must start with file:///. See golang.org/issue/6027.
+	path := filepath.ToSlash(dir)
+	if !strings.HasPrefix(path, "/") {
+		path = "/" + path
+	}
+	return "file://" + path
+}

go/pkg/mod/golang.org/x/telemetry@v0.0.0-20240829154258-f29ab539cc98/internal/proxy/proxy_test.go

@@ -0,0 +1,109 @@
+// Copyright 2023 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 proxy
+
+import (
+	"archive/zip"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestWriteModuleVersion(t *testing.T) {
+	tests := []struct {
+		modulePath, version string
+		files               map[string][]byte
+	}{
+		{
+			modulePath: "mod.test/module",
+			version:    "v1.2.3",
+			files: map[string][]byte{
+				"go.mod":   []byte("module mod.com\n\ngo 1.12"),
+				"const.go": []byte("package module\n\nconst Answer = 42"),
+			},
+		},
+		{
+			modulePath: "mod.test/module",
+			version:    "v1.2.4",
+			files: map[string][]byte{
+				"go.mod":   []byte("module mod.com\n\ngo 1.12"),
+				"const.go": []byte("package module\n\nconst Answer = 43"),
+			},
+		},
+		{
+			modulePath: "mod.test/nogomod",
+			version:    "v0.9.0",
+			files: map[string][]byte{
+				"const.go": []byte("package module\n\nconst Other = \"Other\""),
+			},
+		},
+	}
+	dir := t.TempDir()
+	defer os.RemoveAll(dir)
+	for _, test := range tests {
+		// Since we later assert on the contents of /list, don't use subtests.
+		if err := writeModuleVersion(dir, test.modulePath, test.version, test.files); err != nil {
+			t.Fatal(err)
+		}
+		rootDir := filepath.Join(dir, filepath.FromSlash(test.modulePath), "@v")
+		gomod, err := os.ReadFile(filepath.Join(rootDir, test.version+".mod"))
+		if err != nil {
+			t.Fatal(err)
+		}
+		wantMod, ok := test.files["go.mod"]
+		if !ok {
+			wantMod = []byte("module " + test.modulePath)
+		}
+		if got, want := string(gomod), string(wantMod); got != want {
+			t.Errorf("reading %s/@v/%s.mod: got %q, want %q", test.modulePath, test.version, got, want)
+		}
+		zr, err := zip.OpenReader(filepath.Join(rootDir, test.version+".zip"))
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer zr.Close()
+
+		for _, zf := range zr.File {
+			r, err := zf.Open()
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer r.Close()
+			content, err := io.ReadAll(r)
+			if err != nil {
+				t.Fatal(err)
+			}
+			name := strings.TrimPrefix(zf.Name, fmt.Sprintf("%s@%s/", test.modulePath, test.version))
+			if got, want := string(content), string(test.files[name]); got != want {
+				t.Errorf("unzipping %q: got %q, want %q", zf.Name, got, want)
+			}
+			delete(test.files, name)
+		}
+		for name := range test.files {
+			t.Errorf("file %q not present in the module zip", name)
+		}
+	}
+
+	lists := []struct {
+		modulePath, want string
+	}{
+		{"mod.test/module", "v1.2.3\nv1.2.4\n"},
+		{"mod.test/nogomod", "v0.9.0\n"},
+	}
+
+	for _, test := range lists {
+		fp := filepath.Join(dir, filepath.FromSlash(test.modulePath), "@v", "list")
+		list, err := os.ReadFile(fp)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if got := string(list); got != test.want {
+			t.Errorf("%q/@v/list: got %q, want %q", test.modulePath, got, test.want)
+		}
+	}
+}