Avoid stack overflow error for root_package (guacsec#404)

* Remove stack overflow error

I realized that there could be a stack overflow error in `getCompHelper()` from the file `pkg/components/root_package/root_package.go`.  The reason for this being that there is a recusive call to `getCompHelper()`. Because of this I edited `getCompHelper()` and wrote a test. After figuring out that there was a stack overflow error I created a `vistited` map to solve the issue.

I edited `getCompHelper()` to make it easier for me to test whether there would be a stack overflow error.

``` go
func getCompHelper(ctx context.Context, client graphdb.Client, parentPurl string, dependencies []interface{}, visited map[int64]bool) ([]*PackageComponent, error) {
	//dependencies, err := graphdb.ReadQuery(client, "MATCH (p:Package) WHERE p.purl = $rootPurl WITH p MATCH (p)-[:DependsOn]->(p2:Package) return p2",
	//	map[string]any{"rootPurl": parentPurl})
	//if err != nil {
	//	return nil, err
	//}
	depPackages := []*PackageComponent{}
	for _, dep := range dependencies {
		foundDep, ok := dep.(dbtype.Node)
		if !ok {
			return nil, errors.New("failed to cast to node type")
		}
		if _, ok := visited[foundDep.Id]; ok {
			continue
		}
		visited[foundDep.Id] = true
		foundDepPack := assembler.PackageNode{}
		foundDepPack.Purl, ok = foundDep.Props["purl"].(string)
		if !ok {
			return nil, errors.New("failed to cast purl property to string type")
		}
		deps, err := getCompHelper(ctx, client, foundDepPack.Purl, dependencies, visited)
		if err != nil {
			return nil, err
		}
		depPackages = append(depPackages, &PackageComponent{
			Package:     foundDepPack,
			DepPackages: deps,
		})
	}
	return depPackages, nil
}
```

``` go
func TestGetCompHelperForStackOverflow(t *testing.T) {
	ctx := context.Background()
	ctrl := gomock.NewController(t)
	driver := mocks.NewMockDriver(ctrl)
	client := driver
	parentPurl := "testPurl"
	dependencies := []interface{}{}
	// create a circular dependency to cause stack overflow
	for i := 0; i < 10000; i++ {
		dependencies = append(dependencies, dbtype.Node{
			Id:     int64(i),
			Labels: []string{"Package"},
			Props:  map[string]interface{}{"purl": parentPurl},
		})
	}

	_, err := getCompHelper(ctx, client, parentPurl, dependencies, map[int]bool{})
	if err != nil {
		t.Error(err)
	}
}
```

Signed-off-by: nathannaveen <[email protected]>

* Updated based on code reivew

Signed-off-by: nathannaveen <[email protected]>

---------

Signed-off-by: nathannaveen <[email protected]>

pkg/certifier/components/root_package/root_package.go

@@ -58,12 +58,13 @@ func (q *packageQuery) GetComponents(ctx context.Context, compChan chan<- interf
 		if !ok {
 			return errors.New("failed to cast to node type")
 		}
+		visited := map[int64]bool{foundNode.Id: true}
 		rootPackage := assembler.PackageNode{}
 		rootPackage.Purl, ok = foundNode.Props["purl"].(string)
 		if !ok {
 			return errors.New("failed to cast purl property to string type")
 		}
-		deps, err := getCompHelper(ctx, q.client, rootPackage.Purl)
+		deps, err := getCompHelper(ctx, q.client, rootPackage.Purl, visited)
 		if err != nil {
 			return err
 		}
@@ -76,7 +77,7 @@ func (q *packageQuery) GetComponents(ctx context.Context, compChan chan<- interf
 	return nil
 }
 
-func getCompHelper(ctx context.Context, client graphdb.Client, parentPurl string) ([]*PackageComponent, error) {
+func getCompHelper(ctx context.Context, client graphdb.Client, parentPurl string, visited map[int64]bool) ([]*PackageComponent, error) {
 	dependencies, err := graphdb.ReadQuery(client, "MATCH (p:Package) WHERE p.purl = $rootPurl WITH p MATCH (p)-[:DependsOn]->(p2:Package) return p2",
 		map[string]any{"rootPurl": parentPurl})
 	if err != nil {
@@ -88,12 +89,17 @@ func getCompHelper(ctx context.Context, client graphdb.Client, parentPurl string
 		if !ok {
 			return nil, errors.New("failed to cast to node type")
 		}
+		if visited[foundDep.Id] {
+			continue
+		}
+		visited[foundDep.Id] = true
+
 		foundDepPack := assembler.PackageNode{}
 		foundDepPack.Purl, ok = foundDep.Props["purl"].(string)
 		if !ok {
 			return nil, errors.New("failed to cast purl property to string type")
 		}
-		deps, err := getCompHelper(ctx, client, foundDepPack.Purl)
+		deps, err := getCompHelper(ctx, client, foundDepPack.Purl, visited)
 		if err != nil {
 			return nil, err
 		}