Handle cases where dependencies do not have a specific version associated with them

Author: steiza

main.go

@@ -111,7 +111,12 @@ func (p Purl) String() string {
 		}
 	}
 
-	return prefix + url.QueryEscape(p.Name) + "@" + url.QueryEscape(p.Version)
+	suffix := ""
+	if p.Version != "" {
+		suffix = "@" + url.QueryEscape(p.Version)
+	}
+
+	return prefix + url.QueryEscape(p.Name) + suffix
 }
 
 func getLicense(p *Purl) (string, string, error) {

pkg/dependency-graph/client.go

@@ -83,7 +83,10 @@ func makeQuery(client api.GQLClient, repoOwner, repoName string, manifestCursor,
 		for _, eachDependencyNode := range eachManifestNode.Dependencies.Nodes {
 			packageManager := strings.ToLower(eachDependencyNode.PackageManager)
 			packageName := strings.ToLower(eachDependencyNode.PackageName)
-			packageVersion := eachDependencyNode.Requirements[2:]
+			packageVersion := ""
+			if len(eachDependencyNode.Requirements) > 2 {
+				packageVersion = eachDependencyNode.Requirements[2:]
+			}
 			if strings.HasPrefix(packageVersion, "v") {
 				packageVersion = packageVersion[1:]
 			}