Minor fixes and add test boilerplate, tests have to come later after

mocking library.

internal/output/reporter.go

@@ -3,6 +3,7 @@ package output
 import (
 	"fmt"
 	"io"
+	"strings"
 
 	"github.com/google/osv-scanner/pkg/models"
 )
@@ -21,6 +22,13 @@ func NewReporter(stdout io.Writer, stderr io.Writer, outputAsJSON bool) *Reporte
 	}
 }
 
+// NewVoidReporter creates a reporter that doesn't report to anywhere
+func NewVoidReporter() *Reporter {
+	stdout := new(strings.Builder)
+	stderr := new(strings.Builder)
+	return NewReporter(stdout, stderr, false)
+}
+
 // PrintError writes the given message to stderr, regardless of if the reporter
 // is outputting as JSON or not
 func (r *Reporter) PrintError(msg string) {

pkg/osvscanner/osvscanner.go

@@ -258,9 +258,7 @@ func filterResponse(r *output.Reporter, query osv.BatchedQuery, resp *osv.Batche
 // Perform osv scanner action, with optional reporter to output information
 func DoScan(actions ScannerActions, r *output.Reporter) (models.VulnerabilityResults, error) {
 	if r == nil {
-		stdout := new(strings.Builder)
-		stderr := new(strings.Builder)
-		r = output.NewReporter(stdout, stderr, false)
+		r = output.NewVoidReporter()
 	}
 
 	configManager := config.ConfigManager{
@@ -341,5 +339,5 @@ func DoScan(actions ScannerActions, r *output.Reporter) (models.VulnerabilityRes
 		return models.VulnerabilityResults{}, fmt.Errorf("Failed to hydrate OSV response: %v", err)
 	}
 
-	return groupResponse(r, query, hydratedResp, &configManager), nil
+	return groupResponseBySource(r, query, hydratedResp), nil
 }

pkg/osvscanner/vulnerability_result.go

@@ -6,12 +6,12 @@ import (
 	"github.com/google/osv-scanner/internal/grouper"
 	"github.com/google/osv-scanner/internal/osv"
 	"github.com/google/osv-scanner/internal/output"
-	"github.com/google/osv-scanner/pkg/config"
 	"github.com/google/osv-scanner/pkg/models"
 )
 
-// Convert raw OSV API response into structured vulnerability information.
-func groupResponse(r *output.Reporter, query osv.BatchedQuery, resp *osv.HydratedBatchedResponse, configManager *config.ConfigManager) models.VulnerabilityResults {
+// groupResponseBySource converts raw OSV API response into structured vulnerability information
+// grouped by source location.
+func groupResponseBySource(r *output.Reporter, query osv.BatchedQuery, resp *osv.HydratedBatchedResponse) models.VulnerabilityResults {
 	output := models.VulnerabilityResults{
 		Results: []models.PackageSource{},
 	}

pkg/osvscanner/vulnerability_result_test.go

@@ -0,0 +1,32 @@
+package osvscanner
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/google/osv-scanner/internal/osv"
+	"github.com/google/osv-scanner/internal/output"
+	"github.com/google/osv-scanner/pkg/config"
+	"github.com/google/osv-scanner/pkg/models"
+)
+
+func Test_groupResponseBySource(t *testing.T) {
+	type args struct {
+		r             *output.Reporter
+		query         osv.BatchedQuery
+		resp          *osv.HydratedBatchedResponse
+		configManager *config.ConfigManager
+	}
+	tests := []struct {
+		name string
+		args args
+		want models.VulnerabilityResults
+	}{}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := groupResponseBySource(tt.args.r, tt.args.query, tt.args.resp); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("groupResponse() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}