initial test coverage for Store.Select functions

1 files changed, 222 insertions, 0 deletions

diff --git a/select_test.go b/select_test.go
new file mode 100644
index 0000000..d678aa2
--- /dev/null
+++ b/select_test.go
@@ -0,0 +1,222 @@
+// SPDX-FileCopyrightText: 2026 Stefan Majewsky <majewsky@gmx.net>
+// SPDX-License-Identifier: Apache-2.0
+
+package oblast_test
+
+import (
+	"database/sql"
+	"testing"
+	"time"
+
+	"go.xyrillian.de/oblast"
+	"go.xyrillian.de/oblast/internal/assert"
+	"go.xyrillian.de/oblast/internal/mock"
+	"go.xyrillian.de/oblast/internal/must"
+)
+
+func TestSelectReturningSomeRecords(t *testing.T) {
+	md := mock.NewDriver()
+	db := sql.OpenDB(md)
+
+	type basicRecord struct {
+		ID   int64  `db:"id"`
+		Name string `db:"name"`
+	}
+	store := must.Return(oblast.NewStore[basicRecord](
+		oblast.SqliteDialect(),
+		oblast.TableNameIs("basic_records"),
+		oblast.PrimaryKeyIs("id"),
+	))(t)
+
+	t.Run("using Store.Select", func(t *testing.T) {
+		md.ForQuery(`SELECT * FROM basic_records WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("name", "id").
+			WithRow("foo", 1).
+			WithRow("bar", 2)
+		records := must.Return(store.Select(db, `SELECT * FROM basic_records WHERE id < ?`, 3))(t)
+		assert.SliceEqual(t, records,
+			basicRecord{1, "foo"},
+			basicRecord{2, "bar"},
+		)
+	})
+
+	t.Run("using Store.SelectWhere", func(t *testing.T) {
+		md.ForQuery(`SELECT "id", "name" FROM "basic_records" WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("id", "name").
+			WithRow(1, "ffoo").
+			WithRow(2, "bbar")
+		records := must.Return(store.SelectWhere(db, `id < ?`, 3))(t)
+		assert.SliceEqual(t, records,
+			basicRecord{1, "ffoo"},
+			basicRecord{2, "bbar"},
+		)
+	})
+
+	t.Run("using Store.SelectOne", func(t *testing.T) {
+		md.ForQuery(`SELECT * FROM basic_records WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("name", "id").
+			WithRow("fffoo", 1).
+			WithRow("bbbar", 2)
+		record := must.Return(store.SelectOne(db, `SELECT * FROM basic_records WHERE id < ?`, 3))(t)
+		assert.Equal(t, record, basicRecord{1, "fffoo"})
+	})
+
+	t.Run("using Store.SelectOneWhere", func(t *testing.T) {
+		md.ForQuery(`SELECT "id", "name" FROM "basic_records" WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("id", "name").
+			WithRow(1, "ffffoo").
+			WithRow(2, "bbbbar")
+		record := must.Return(store.SelectOneWhere(db, `id < ?`, 3))(t)
+		assert.Equal(t, record, basicRecord{1, "ffffoo"})
+	})
+}
+
+func TestSelectReturningNoRecords(t *testing.T) {
+	md := mock.NewDriver()
+	db := sql.OpenDB(md)
+
+	type basicRecord struct {
+		ID   int64  `db:"id"`
+		Name string `db:"name"`
+	}
+	store := must.Return(oblast.NewStore[basicRecord](
+		oblast.SqliteDialect(),
+		oblast.TableNameIs("basic_records"),
+		oblast.PrimaryKeyIs("id"),
+	))(t)
+
+	t.Run("using Store.Select", func(t *testing.T) {
+		md.ForQuery(`SELECT * FROM basic_records WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("name", "id")
+		records := must.Return(store.Select(db, `SELECT * FROM basic_records WHERE id < ?`, 3))(t)
+		assert.SliceEqual(t, records, nil...)
+	})
+
+	t.Run("using Store.SelectWhere", func(t *testing.T) {
+		md.ForQuery(`SELECT "id", "name" FROM "basic_records" WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("id", "name")
+		records := must.Return(store.SelectWhere(db, `id < ?`, 3))(t)
+		assert.SliceEqual(t, records, nil...)
+	})
+
+	t.Run("using Store.SelectOne", func(t *testing.T) {
+		md.ForQuery(`SELECT * FROM basic_records WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("name", "id")
+		_, err := store.SelectOne(db, `SELECT * FROM basic_records WHERE id < ?`, 3)
+		assert.Equal(t, err.Error(), sql.ErrNoRows.Error())
+	})
+
+	t.Run("using Store.SelectOneWhere", func(t *testing.T) {
+		md.ForQuery(`SELECT "id", "name" FROM "basic_records" WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("id", "name")
+		_, err := store.SelectOneWhere(db, `id < ?`, 3)
+		assert.Equal(t, err.Error(), sql.ErrNoRows.Error())
+	})
+}
+
+func TestSelectIntoUnexpectedField(t *testing.T) {
+	md := mock.NewDriver()
+	db := sql.OpenDB(md)
+
+	type basicRecord struct {
+		ID          int64  `db:"id"`
+		Description string `db:"desc"` // but DB knows only the field "name"!
+	}
+	store := must.Return(oblast.NewStore[basicRecord](
+		oblast.SqliteDialect(),
+		oblast.TableNameIs("basic_records"),
+		oblast.PrimaryKeyIs("id"),
+	))(t)
+
+	expectedError := "result has column \"name\" in position 0, but no field in type basicRecord has `db:\"name\"`"
+
+	// NOTE: This problem cannot occur with SelectWhere() and SelectOneWhere() because of their use of query generation.
+
+	t.Run("using Store.Select", func(t *testing.T) {
+		md.ForQuery(`SELECT * FROM basic_records WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("name", "id").
+			WithRow("foo", 1).
+			WithRow("bar", 2)
+		_, err := store.Select(db, `SELECT * FROM basic_records WHERE id < ?`, 3)
+		assert.Equal(t, err.Error(), expectedError)
+	})
+
+	t.Run("using Store.SelectOne", func(t *testing.T) {
+		md.ForQuery(`SELECT * FROM basic_records WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("name", "id").
+			WithRow("ffoo", 1).
+			WithRow("bbar", 2)
+		_, err := store.SelectOne(db, `SELECT * FROM basic_records WHERE id < ?`, 3)
+		assert.Equal(t, err.Error(), expectedError)
+	})
+}
+
+func TestSelectWithScanError(t *testing.T) {
+	md := mock.NewDriver()
+	db := sql.OpenDB(md)
+
+	type basicRecord struct {
+		ID        int64     `db:"id"`
+		CreatedAt time.Time `db:"created_at"` // but the DB will give us strings that are not timestamps
+	}
+	store := must.Return(oblast.NewStore[basicRecord](
+		oblast.SqliteDialect(),
+		oblast.TableNameIs("basic_records"),
+		oblast.PrimaryKeyIs("id"),
+	))(t)
+
+	expectedError := `sql: Scan error on column index 1, name "created_at": unsupported Scan, storing driver.Value type string into type *time.Time`
+
+	t.Run("using Store.Select", func(t *testing.T) {
+		md.ForQuery(`SELECT * FROM basic_records WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("id", "created_at").
+			WithRow(1, "foo").
+			WithRow(2, "bar")
+		_, err := store.Select(db, `SELECT * FROM basic_records WHERE id < ?`, 3)
+		assert.Equal(t, err.Error(), expectedError)
+	})
+
+	t.Run("using Store.SelectWhere", func(t *testing.T) {
+		md.ForQuery(`SELECT "id", "created_at" FROM "basic_records" WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("id", "created_at").
+			WithRow(1, "ffoo").
+			WithRow(2, "bbar")
+		_, err := store.SelectWhere(db, `id < ?`, 3)
+		assert.Equal(t, err.Error(), expectedError)
+	})
+
+	t.Run("using Store.SelectOne", func(t *testing.T) {
+		md.ForQuery(`SELECT * FROM basic_records WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("id", "created_at").
+			WithRow(1, "fffoo").
+			WithRow(2, "bbbar")
+		_, err := store.SelectOne(db, `SELECT * FROM basic_records WHERE id < ?`, 3)
+		assert.Equal(t, err.Error(), expectedError)
+	})
+
+	t.Run("using Store.SelectOneWhere", func(t *testing.T) {
+		md.ForQuery(`SELECT "id", "created_at" FROM "basic_records" WHERE id < ?`).
+			ExpectQueryWithArgs(3).
+			AndReturnColumns("id", "created_at").
+			WithRow(1, "ffffoo").
+			WithRow(2, "bbbbar")
+		_, err := store.SelectOneWhere(db, `id < ?`, 3)
+		assert.Equal(t, err.Error(), expectedError)
+	})
+}
+
+// TODO: test error capture during Rows.Close()
+// TODO: check for maximum test coverage in select.go