add test coverage

1 files changed, 183 insertions, 0 deletions

diff --git a/interface_test.go b/interface_test.go
new file mode 100644
index 0000000..68f1dc2
--- /dev/null
+++ b/interface_test.go
@@ -0,0 +1,183 @@
+// SPDX-FileCopyrightText: 2026 Stefan Majewsky <majewsky@gmx.net>
+// SPDX-License-Identifier: Apache-2.0
+
+package gg_pgx_test
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"testing"
+
+	"go.xyrillian.de/gg/assert"
+	"go.xyrillian.de/gg/errext"
+	"go.xyrillian.de/gg/gsql"
+	"go.xyrillian.de/gg/pgruntime"
+
+	gg_pgx "go.xyrillian.de/gg-pgx"
+)
+
+// NOTE: There is not a lot of test coverage for the methods in `interface.go`, which is intentional:
+// These are just boilerplate implementations where, if it compiles at all, it is all but guaranteed to work as intended.
+
+var defaultBehavior pgruntime.ConnectionBehavior
+
+func TestMain(m *testing.M) {
+	pgruntime.WithTestDB(m, m.Run)
+}
+
+func TestConn(t *testing.T) {
+	conn, _ := gg_pgx.SingleConnector().ConnectForTest(t, defaultBehavior)
+	testConnectionHandle(t, conn)
+}
+
+func TestPool(t *testing.T) {
+	pool, _ := gg_pgx.PoolConnector().ConnectForTest(t, defaultBehavior)
+	testConnectionHandle(t, pool)
+}
+
+func TestPoolConn(t *testing.T) {
+	pool, _ := gg_pgx.PoolConnector().ConnectForTest(t, defaultBehavior)
+	t.Cleanup(pool.Close)
+
+	conn, err := pool.Acquire(t.Context())
+	if assert.ErrEqual(t, err, nil) {
+		testConnectionHandle(t, conn)
+	}
+}
+
+func testConnectionHandle[H gsql.ConnectionHandle](t *testing.T, conn H) {
+	ctx := t.Context()
+	t.Cleanup(func() {
+		assert.ErrEqual(t, conn.GSQLClose(ctx), nil)
+	})
+
+	// test GSQLPrepare() + Exec()
+	_, err := execQuery(ctx, conn, `CREATE TABLE people (id BIGSERIAL PRIMARY KEY, name TEXT NOT NULL)`, nil)
+	if !assert.ErrEqual(t, err, nil) {
+		t.FailNow()
+	}
+	for _, name := range []string{"Alice", "Bob", "Carol"} {
+		_, err = execQuery(ctx, conn, `INSERT INTO people (name) VALUES ($1)`, []any{name})
+		if !assert.ErrEqual(t, err, nil) {
+			t.FailNow()
+		}
+	}
+
+	// test GSQLPrepare() + QueryRow()
+	var id int64
+	err = queryRow(ctx, conn, `SELECT id FROM people WHERE name = $1`, []any{"Bob"}, []any{&id})
+	if !assert.ErrEqual(t, err, nil) {
+		t.FailNow()
+	}
+	assert.Equal(t, id, 2)
+
+	// test GSQLQuery()
+	type person struct {
+		ID   int64
+		Name string
+	}
+	var people []person
+	err = foreachRow(t, ctx, conn, `SELECT id, name FROM people ORDER BY id`, nil, []string{"id", "name"}, func(scan func(slots ...any) error) error {
+		var p person
+		err := scan(&p.ID, &p.Name)
+		if err != nil {
+			return err
+		}
+		people = append(people, p)
+		return nil
+	})
+	if !assert.ErrEqual(t, err, nil) {
+		t.FailNow()
+	}
+	assert.Equal(t, people, []person{
+		{1, "Alice"},
+		{2, "Bob"},
+		{3, "Carol"},
+	})
+
+	// test GSQLTransact() + success
+	err = conn.GSQLTransact(ctx, func(tx gsql.Handle) error {
+		_, err := execQuery(ctx, tx, `UPDATE people SET name = $1 WHERE id = $2`, []any{"Carolin", 3})
+		return err
+	})
+	if !assert.ErrEqual(t, err, nil) {
+		t.FailNow()
+	}
+
+	// check that the transaction was committed
+	var name string
+	err = queryRow(ctx, conn, `SELECT name FROM people WHERE id = $1`, []any{3}, []any{&name})
+	if !assert.ErrEqual(t, err, nil) {
+		t.FailNow()
+	}
+	assert.Equal(t, name, "Carolin")
+
+	// test GSQLTransact() + error
+	err = conn.GSQLTransact(ctx, func(tx gsql.Handle) error {
+		_, err := execQuery(ctx, tx, `UPDATE people SET name = $1 WHERE id = $2`, []any{"Allen", 1})
+		if err != nil {
+			return err
+		}
+
+		// check that the change is visible within the transaction
+		var name string
+		err = queryRow(ctx, tx, `SELECT name FROM people WHERE id = $1`, []any{1}, []any{&name})
+		if !assert.ErrEqual(t, err, nil) {
+			t.FailNow()
+		}
+		assert.Equal(t, name, "Allen")
+
+		return errors.New("this was a bad idea")
+	})
+	if !assert.ErrEqual(t, err, "this was a bad idea") {
+		t.FailNow()
+	}
+
+	// check that the transaction was *not* committed
+	err = queryRow(ctx, conn, `SELECT name FROM people WHERE id = $1`, []any{1}, []any{&name})
+	if !assert.ErrEqual(t, err, nil) {
+		t.FailNow()
+	}
+	assert.Equal(t, name, "Alice")
+}
+
+// Convenience function for executing a one-off SQL query returning no rows.
+func execQuery(ctx context.Context, db gsql.Handle, query string, args []any) (sql.Result, error) {
+	stmt, err := db.GSQLPrepare(ctx, query, false)
+	if err != nil {
+		return nil, err
+	}
+	result, err := stmt.Exec(ctx, args)
+	return result, errext.WithCleanup(err, "stmt.Close", stmt.Close())
+}
+
+// Convenience function for executing a one-off SQL query returning one row.
+func queryRow(ctx context.Context, db gsql.Handle, query string, args, slots []any) error {
+	stmt, err := db.GSQLPrepare(ctx, query, true) // repeated=true does not technically make sense, but provides code coverage
+	if err != nil {
+		return err
+	}
+	err = stmt.QueryRow(ctx, args, slots)
+	return errext.WithCleanup(err, "stmt.Close", stmt.Close())
+}
+
+// Convenience function for executing a one-off SQL query returning several rows.
+func foreachRow(t *testing.T, ctx context.Context, db gsql.Handle, query string, args []any, expectedColumnNames []string, action func(scan func(slots ...any) error) error) error {
+	t.Helper()
+	rows, err := db.GSQLQuery(ctx, query, args)
+	if err != nil {
+		return err
+	}
+	columns, err := rows.Columns()
+	if assert.ErrEqual(t, err, nil) {
+		assert.Equal(t, columns, expectedColumnNames)
+	}
+	for rows.Next() {
+		err := action(rows.Scan)
+		if err != nil {
+			return errext.WithCleanup(err, "rows.Close", rows.Close())
+		}
+	}
+	return rows.Close()
+}