test: add data-fix runner characterization tests

internal/database/data_fixes_test.go

@@ -0,0 +1,142 @@
+package database
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"reflect"
+	"testing"
+
+	dbfixes "mal/internal/database/fixes"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func TestRunDataFixListRunsUnappliedFixesAndRecordsSuccesses(t *testing.T) {
+	sqlDB := newEmptyTestDB(t)
+	defer closeTestDB(t, sqlDB)
+
+	var applied []string
+	fixes := []dbfixes.Fix{
+		{
+			ID: "first",
+			Apply: func(ctx context.Context, sqlDB *sql.DB, deps dbfixes.Dependencies) error {
+				applied = append(applied, "first")
+				return nil
+			},
+		},
+		{
+			ID: "second",
+			Apply: func(ctx context.Context, sqlDB *sql.DB, deps dbfixes.Dependencies) error {
+				applied = append(applied, "second")
+				return nil
+			},
+		},
+	}
+
+	if err := runDataFixList(sqlDB, dbfixes.Dependencies{}, fixes); err != nil {
+		t.Fatalf("runDataFixList: %v", err)
+	}
+
+	if !reflect.DeepEqual(applied, []string{"first", "second"}) {
+		t.Fatalf("applied fixes = %v, want [first second]", applied)
+	}
+	assertAppliedDataFixes(context.Background(), t, sqlDB, []string{"first", "second"})
+}
+
+func TestRunDataFixListSkipsAlreadyAppliedFixes(t *testing.T) {
+	sqlDB := newEmptyTestDB(t)
+	defer closeTestDB(t, sqlDB)
+
+	ctx := context.Background()
+	if _, err := sqlDB.ExecContext(ctx, `CREATE TABLE data_fixes (id TEXT PRIMARY KEY, applied_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP)`); err != nil {
+		t.Fatalf("create data_fixes: %v", err)
+	}
+	if _, err := sqlDB.ExecContext(ctx, `INSERT INTO data_fixes (id) VALUES ('already-applied')`); err != nil {
+		t.Fatalf("insert applied fix: %v", err)
+	}
+
+	var ran bool
+	fixes := []dbfixes.Fix{
+		{
+			ID: "already-applied",
+			Apply: func(ctx context.Context, sqlDB *sql.DB, deps dbfixes.Dependencies) error {
+				ran = true
+				return nil
+			},
+		},
+	}
+
+	if err := runDataFixList(sqlDB, dbfixes.Dependencies{}, fixes); err != nil {
+		t.Fatalf("runDataFixList: %v", err)
+	}
+
+	if ran {
+		t.Fatal("already applied fix ran")
+	}
+	assertAppliedDataFixes(context.Background(), t, sqlDB, []string{"already-applied"})
+}
+
+func TestRunDataFixListDoesNotRecordFailedFix(t *testing.T) {
+	sqlDB := newEmptyTestDB(t)
+	defer closeTestDB(t, sqlDB)
+
+	fixErr := errors.New("boom")
+	fixes := []dbfixes.Fix{
+		{
+			ID: "fails",
+			Apply: func(ctx context.Context, sqlDB *sql.DB, deps dbfixes.Dependencies) error {
+				return fixErr
+			},
+		},
+	}
+
+	err := runDataFixList(sqlDB, dbfixes.Dependencies{}, fixes)
+	if !errors.Is(err, fixErr) {
+		t.Fatalf("runDataFixList error = %v, want wrapped %v", err, fixErr)
+	}
+
+	assertAppliedDataFixes(context.Background(), t, sqlDB, nil)
+}
+
+func newEmptyTestDB(t *testing.T) *sql.DB {
+	t.Helper()
+
+	sqlDB, err := sql.Open("sqlite3", ":memory:")
+	if err != nil {
+		t.Fatalf("open sqlite: %v", err)
+	}
+	sqlDB.SetMaxOpenConns(1)
+
+	return sqlDB
+}
+
+func assertAppliedDataFixes(ctx context.Context, t *testing.T, sqlDB *sql.DB, want []string) {
+	t.Helper()
+
+	rows, err := sqlDB.QueryContext(ctx, `SELECT id FROM data_fixes ORDER BY id`)
+	if err != nil {
+		t.Fatalf("query data_fixes: %v", err)
+	}
+	defer func() {
+		if err := rows.Close(); err != nil {
+			t.Errorf("close rows: %v", err)
+		}
+	}()
+
+	var got []string
+	for rows.Next() {
+		var id string
+		if err := rows.Scan(&id); err != nil {
+			t.Fatalf("scan data_fix id: %v", err)
+		}
+		got = append(got, id)
+	}
+	if err := rows.Err(); err != nil {
+		t.Fatalf("iterate data_fixes: %v", err)
+	}
+
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("applied data fixes = %v, want %v", got, want)
+	}
+}