Refactor for unit testing

cmd/internal/planetscale_edge_mysql.go

@@ -136,7 +136,7 @@ func (p planetScaleEdgeMySQLAccess) GetTableNames(ctx context.Context, psc Plane
 		}
 
 		// skip any that are Vitess's GC tables.
-		if !gcTableNameRegexp.MatchString(name) && !vreplRegex.MatchString(name) {
+		if !filterTable(name) {
 			tables = append(tables, name)
 		}
 	}
@@ -148,6 +148,10 @@ func (p planetScaleEdgeMySQLAccess) GetTableNames(ctx context.Context, psc Plane
 	return tables, err
 }
 
+func filterTable(name string) bool {
+	return gcTableNameRegexp.MatchString(name) || vreplRegex.MatchString(name)
+}
+
 func (p planetScaleEdgeMySQLAccess) GetTableSchema(ctx context.Context, psc PlanetScaleSource, tableName string) (map[string]PropertyType, error) {
 	properties := map[string]PropertyType{}
 

cmd/internal/planetscale_edge_mysql_test.go

@@ -0,0 +1,53 @@
+package internal
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFilterNames_CanFilterInternalVitessTables(t *testing.T) {
+	var tests = []struct {
+		name      string
+		tableName string
+		filtered  bool
+	}{
+		{
+			name:      "filters_vrepl_tables",
+			tableName: "_750a3e1f_e6f3_5249_82af_82f5d325ecab_20240528153135_vrepl",
+			filtered:  true,
+		},
+		{
+			name:      "filters_vt_DROP_tables",
+			tableName: "_vt_DROP_6ace8bcef73211ea87e9f875a4d24e90_20200915120410",
+			filtered:  true,
+		},
+		{
+			name:      "filters_vt_HOLD_tables",
+			tableName: "_vt_HOLD_6ace8bcef73211ea87e9f875a4d24e90_20200915120410",
+			filtered:  true,
+		},
+		{
+			name:      "filters_vt_EVAC_tables",
+			tableName: "_vt_EVAC_6ace8bcef73211ea87e9f875a4d24e90_20200915120410",
+			filtered:  true,
+		},
+		{
+			name:      "filters_vt_PURGE_tables",
+			tableName: "_vt_PURGE_6ace8bcef73211ea87e9f875a4d24e90_20200915120410",
+			filtered:  true,
+		},
+		{
+			name:      "does_not_filter_regular_table",
+			tableName: "customers",
+			filtered:  false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			filteredResult := filterTable(tt.tableName)
+			assert.Equal(t, tt.filtered, filteredResult)
+		})
+	}
+}