test: add CatalogDB/CatalogTx interface contract tests

Author: retran

mdl/catalog/catalogdb_test.go

@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build !js
+
+package catalog
+
+import (
+	"database/sql"
+	"testing"
+)
+
+// TestCatalogDBContract verifies that SqliteCatalogDB satisfies the CatalogDB
+// interface contract: basic CRUD, transactions, and cleanup.
+func TestCatalogDBContract(t *testing.T) {
+	db, err := NewSqliteCatalogDB()
+	if err != nil {
+		t.Fatalf("NewSqliteCatalogDB: %v", err)
+	}
+	defer db.Close()
+
+	// Exec — create a table.
+	_, err = db.Exec("CREATE TABLE test_contract (id INTEGER PRIMARY KEY, name TEXT)")
+	if err != nil {
+		t.Fatalf("Exec CREATE TABLE: %v", err)
+	}
+
+	// Exec — insert a row.
+	res, err := db.Exec("INSERT INTO test_contract (id, name) VALUES (?, ?)", 1, "alpha")
+	if err != nil {
+		t.Fatalf("Exec INSERT: %v", err)
+	}
+	n, err := res.RowsAffected()
+	if err != nil {
+		t.Fatalf("RowsAffected: %v", err)
+	}
+	if n != 1 {
+		t.Errorf("expected 1 row affected, got %d", n)
+	}
+
+	// QueryRow — read it back.
+	var name string
+	row := db.QueryRow("SELECT name FROM test_contract WHERE id = ?", 1)
+	if err := row.Scan(&name); err != nil {
+		t.Fatalf("QueryRow Scan: %v", err)
+	}
+	if name != "alpha" {
+		t.Errorf("expected alpha, got %q", name)
+	}
+
+	// Query — list rows.
+	rows, err := db.Query("SELECT id, name FROM test_contract ORDER BY id")
+	if err != nil {
+		t.Fatalf("Query: %v", err)
+	}
+	defer rows.Close()
+	count := 0
+	for rows.Next() {
+		var id int
+		var n string
+		if err := rows.Scan(&id, &n); err != nil {
+			t.Fatalf("rows.Scan: %v", err)
+		}
+		count++
+	}
+	if err := rows.Err(); err != nil {
+		t.Fatalf("rows.Err: %v", err)
+	}
+	if count != 1 {
+		t.Errorf("expected 1 row, got %d", count)
+	}
+}
+
+func TestCatalogTxContract(t *testing.T) {
+	db, err := NewSqliteCatalogDB()
+	if err != nil {
+		t.Fatalf("NewSqliteCatalogDB: %v", err)
+	}
+	defer db.Close()
+
+	_, err = db.Exec("CREATE TABLE test_tx (id INTEGER PRIMARY KEY, val TEXT)")
+	if err != nil {
+		t.Fatalf("Exec CREATE TABLE: %v", err)
+	}
+
+	// Begin + Prepare + Exec + Commit.
+	tx, err := db.Begin()
+	if err != nil {
+		t.Fatalf("Begin: %v", err)
+	}
+	stmt, err := tx.Prepare("INSERT INTO test_tx (id, val) VALUES (?, ?)")
+	if err != nil {
+		t.Fatalf("Prepare: %v", err)
+	}
+	for i := 1; i <= 3; i++ {
+		if _, err := stmt.Exec(i, "row"); err != nil {
+			t.Fatalf("stmt.Exec(%d): %v", i, err)
+		}
+	}
+	stmt.Close()
+	if err := tx.Commit(); err != nil {
+		t.Fatalf("Commit: %v", err)
+	}
+
+	// Verify rows persisted.
+	var count int
+	if err := db.QueryRow("SELECT COUNT(*) FROM test_tx").Scan(&count); err != nil {
+		t.Fatalf("QueryRow after commit: %v", err)
+	}
+	if count != 3 {
+		t.Errorf("expected 3 rows after commit, got %d", count)
+	}
+
+	// Begin + Rollback — rows should not persist.
+	tx2, err := db.Begin()
+	if err != nil {
+		t.Fatalf("Begin (rollback): %v", err)
+	}
+	if _, err := tx2.Exec("INSERT INTO test_tx (id, val) VALUES (4, 'gone')"); err != nil {
+		t.Fatalf("Exec in rollback tx: %v", err)
+	}
+	if err := tx2.Rollback(); err != nil {
+		t.Fatalf("Rollback: %v", err)
+	}
+
+	if err := db.QueryRow("SELECT COUNT(*) FROM test_tx").Scan(&count); err != nil {
+		t.Fatalf("QueryRow after rollback: %v", err)
+	}
+	if count != 3 {
+		t.Errorf("expected 3 rows after rollback, got %d", count)
+	}
+}
+
+// TestInterfaceSatisfaction verifies compile-time interface compliance.
+func TestInterfaceSatisfaction(t *testing.T) {
+	var _ CatalogDB = (*SqliteCatalogDB)(nil)
+	var _ CatalogTx = (*sql.Tx)(nil)
+}