Remove potential Go module versions from shortened names (#571)

* Expand shortened name if package name appears to be a module version

* Correct version regexp, use more generic names in tests, remove an empty line

* 80 character columns

* Remove first matching Go module version from path

* Test and fix multi-version case

Co-authored-by: Maggie Nolan <nolanmar@google.com>

internal/graph/graph.go

@@ -34,6 +34,8 @@ var (
 	// Removes package name and method arugments for Go function names.
 	// See tests for examples.
 	goRegExp = regexp.MustCompile(`^(?:[\w\-\.]+\/)+(.+)`)
+	// Removes potential module versions in a package path.
+	goVerRegExp = regexp.MustCompile(`^(.*?)/v(?:[2-9]|[1-9][0-9]+)([./].*)$`)
 	// Strips C++ namespace prefix from a C++ function / method name.
 	// NOTE: Make sure to keep the template parameters in the name. Normally,
 	// template parameters are stripped from the C++ names but when
@@ -440,6 +442,7 @@ func newTree(prof *profile.Profile, o *Options) (g *Graph) {
 // ShortenFunctionName returns a shortened version of a function's name.
 func ShortenFunctionName(f string) string {
 	f = cppAnonymousPrefixRegExp.ReplaceAllString(f, "")
+	f = goVerRegExp.ReplaceAllString(f, `${1}${2}`)
 	for _, re := range []*regexp.Regexp{goRegExp, javaRegExp, cppRegExp} {
 		if matches := re.FindStringSubmatch(f); len(matches) >= 2 {
 			return strings.Join(matches[1:], "")

internal/graph/graph_test.go

@@ -451,6 +451,38 @@ func TestShortenFunctionName(t *testing.T) {
 			"github.com/blah/blah/vendor/gopkg.in/redis.v3.(*baseClient).(github.com/blah/blah/vendor/gopkg.in/redis.v3.process)-fm",
 			"redis.v3.(*baseClient).(github.com/blah/blah/vendor/gopkg.in/redis.v3.process)-fm",
 		},
+		{
+			"github.com/foo/bar/v4.(*Foo).Bar",
+			"bar.(*Foo).Bar",
+		},
+		{
+			"github.com/foo/bar/v4/baz.Foo.Bar",
+			"baz.Foo.Bar",
+		},
+		{
+			"github.com/foo/bar/v123.(*Foo).Bar",
+			"bar.(*Foo).Bar",
+		},
+		{
+			"github.com/foobar/v0.(*Foo).Bar",
+			"v0.(*Foo).Bar",
+		},
+		{
+			"github.com/foobar/v1.(*Foo).Bar",
+			"v1.(*Foo).Bar",
+		},
+		{
+			"example.org/v2xyz.Foo",
+			"v2xyz.Foo",
+		},
+		{
+			"github.com/foo/bar/v4/v4.(*Foo).Bar",
+			"v4.(*Foo).Bar",
+		},
+		{
+			"github.com/foo/bar/v4/foo/bar/v4.(*Foo).Bar",
+			"v4.(*Foo).Bar",
+		},
 		{
 			"java.util.concurrent.ThreadPoolExecutor$Worker.run",
 			"ThreadPoolExecutor$Worker.run",