chore: add tests for parser registration

Signed-off-by: Frederick F. Kautz IV <frederick@testifysec.com>

pkg/metadatastorage/attestationcollection/parser_registry_test.go

@@ -0,0 +1,26 @@
+package attestationcollection
+
+import (
+	"context"
+	"encoding/json"
+	"testing"
+
+	"github.com/in-toto/archivista/ent"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRegister(t *testing.T) {
+	// Define a mock parser function
+	mockParser := func(ctx context.Context, tx *ent.Tx, attestation *ent.Attestation, attestationType string, message json.RawMessage) error {
+		return nil
+	}
+
+	// Register the mock parser
+	Register("mockType", mockParser)
+
+	// Check if the parser is registered
+	registeredParser, exists := registeredParsers["mockType"]
+	var typedParser AttestationParser = mockParser
+	assert.True(t, exists, "Parser should be registered")
+	assert.IsType(t, typedParser, registeredParser, "Registered parser should match the mock parser")
+}