Fix apiviewgo download paths (#8856) (#8883)

* apiviewgo downloads to os.TempDir instead of os.UserHomeDir

Author: praveenkuttappan

src/go/cmd/download.go

@@ -139,13 +139,14 @@ func mustEscape(modPath string) string {
 // downloadDir creates a directory to store downloaded module zips and source.
 // Callers are responsible for removing the directory when they're done with it.
 func downloadDir() (string, error) {
-	root, err := os.UserHomeDir()
+	root := os.TempDir()
+	err := os.MkdirAll(root, 0700)
 	if err != nil {
-		root = os.TempDir()
+		return "", fmt.Errorf("failed to create root directory %q for downloads: %w", root, err)
 	}
 	d, err := os.MkdirTemp(root, "apiviewgo")
 	if err != nil {
-		err = fmt.Errorf("failed to create download directory: %w", err)
+		err = fmt.Errorf("failed to create download directory %q: %w", d, err)
 	}
 	return d, err
 }

src/go/cmd/module.go

@@ -89,7 +89,7 @@ func NewModule(dir string) (*Module, error) {
 					return filepath.SkipDir
 				}
 			}
-			p, err := NewPkg(path, m.ModFile.Module.Mod.Path)
+			p, err := NewPkg(path, m.ModFile.Module.Mod.Path, dir)
 			if err == nil {
 				m.Packages[baseImportPath+p.Name()] = p
 			} else if !errors.Is(err, ErrNoPackages) {

src/go/cmd/pkg.go

@@ -51,8 +51,11 @@ type Pkg struct {
 }
 
 // NewPkg loads the package in the specified directory.
-// It's required there is only one package in the directory.
-func NewPkg(dir, modulePath string) (*Pkg, error) {
+//
+//   - dir is the directory containing the package
+//   - modulePath is the import path of the module containing the package
+//   - moduleRoot is the root directory of the module on disk i.e., the directory containing its go.mod
+func NewPkg(dir, modulePath, moduleRoot string) (*Pkg, error) {
 	pk := &Pkg{
 		modulePath:  modulePath,
 		c:           newContent(),
@@ -61,12 +64,8 @@ func NewPkg(dir, modulePath string) (*Pkg, error) {
 	}
 	modulePathWithoutVersion := strings.TrimSuffix(versionReg.ReplaceAllString(modulePath, "/"), "/")
 	moduleName := filepath.Base(modulePathWithoutVersion)
-	if _, after, found := strings.Cut(dir, moduleName); found {
-		pk.relName = moduleName
-		if after != "" && after[0] != '@' {
-			pk.relName += after
-		}
-		pk.relName = strings.ReplaceAll(pk.relName, "\\", "/")
+	if _, after, found := strings.Cut(dir, moduleRoot); found {
+		pk.relName = strings.ReplaceAll(moduleName+after, "\\", "/")
 	} else {
 		return nil, errors.New(dir + " isn't part of module " + moduleName)
 	}

src/go/cmd/pkg_test.go

@@ -0,0 +1,48 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package cmd
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestName(t *testing.T) {
+	for _, test := range []struct {
+		modulePath, moduleRoot, pkgPath, want string
+	}{
+		{
+			modulePath: "test_package_name",
+			moduleRoot: "testdata/test_package_name/test_package_name@v1.0.0",
+			want:       "test_package_name",
+		},
+		{
+			modulePath: "test_package_name",
+			moduleRoot: "testdata/test_package_name/test_package_name@v1.0.0",
+			pkgPath:    "subpackage",
+			want:       "test_package_name/subpackage",
+		},
+		{
+			modulePath: "test_subpackage",
+			moduleRoot: "testdata/test_subpackage",
+			want:       "test_subpackage",
+		},
+		{
+			modulePath: "test_subpackage",
+			moduleRoot: "testdata/test_subpackage",
+			pkgPath:    "subpackage",
+			want:       "test_subpackage/subpackage",
+		},
+	} {
+		t.Run("", func(t *testing.T) {
+			d, err := filepath.Abs(test.moduleRoot)
+			require.NoError(t, err)
+			p, err := NewPkg(filepath.Join(d, test.pkgPath), test.modulePath, d)
+			require.NoError(t, err)
+			require.Equal(t, test.want, p.Name())
+		})
+	}
+}

src/go/cmd/testdata/test_package_name/test_package_name@v1.0.0/go.mod

@@ -0,0 +1,3 @@
+module test_package_name
+
+go 1.18

src/go/cmd/testdata/test_package_name/test_package_name@v1.0.0/subpackage/test.go

@@ -0,0 +1,3 @@
+package subpackage
+
+type S string

src/go/cmd/testdata/test_package_name/test_package_name@v1.0.0/test.go

@@ -0,0 +1,3 @@
+package test_package_name
+
+type S string