feat(db): SQLite 连接与迁移框架（embed 迁移/事务校验/PG 预留 M4）

internal/db/db_test.go

@@ -0,0 +1,136 @@
+package db
+
+import (
+	"context"
+	"errors"
+	"io"
+	"log/slog"
+	"path/filepath"
+	"testing"
+)
+
+// testLogger returns a logger that writes nowhere, keeping test output clean.
+func testLogger() *slog.Logger {
+	return slog.New(slog.NewTextHandler(io.Discard, nil))
+}
+
+func TestOpen_InMemory_正常(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+
+	db, err := Open(ctx, ":memory:", testLogger())
+	if err != nil {
+		t.Fatalf("Open(:memory:) error: %v", err)
+	}
+	defer db.Close()
+
+	if err := db.PingContext(ctx); err != nil {
+		t.Fatalf("ping in-memory db: %v", err)
+	}
+
+	var n int
+	if err := db.QueryRowContext(ctx, "SELECT count(*) FROM sqlite_master WHERE type='table'").Scan(&n); err != nil {
+		t.Fatalf("query sqlite_master: %v", err)
+	}
+	if n != 0 {
+		t.Fatalf("expected no tables before migrations, got %d", n)
+	}
+}
+
+func TestOpen_InMemory_NilLogger_正常(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+
+	// A nil logger must not panic and must produce a usable connection.
+	db, err := Open(ctx, ":memory:", nil)
+	if err != nil {
+		t.Fatalf("Open with nil logger error: %v", err)
+	}
+	defer db.Close()
+	if err := db.PingContext(ctx); err != nil {
+		t.Fatalf("ping with nil logger: %v", err)
+	}
+}
+
+func TestOpen_InMemory_Isolation_并发(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+
+	db1, err := Open(ctx, ":memory:", testLogger())
+	if err != nil {
+		t.Fatalf("open db1: %v", err)
+	}
+	defer db1.Close()
+	db2, err := Open(ctx, ":memory:", testLogger())
+	if err != nil {
+		t.Fatalf("open db2: %v", err)
+	}
+	defer db2.Close()
+
+	if _, err := db1.ExecContext(ctx, "CREATE TABLE t1(x)"); err != nil {
+		t.Fatalf("create table in db1: %v", err)
+	}
+
+	var n int
+	if err := db2.QueryRowContext(ctx, "SELECT count(*) FROM sqlite_master WHERE name='t1'").Scan(&n); err != nil {
+		t.Fatalf("query db2: %v", err)
+	}
+	if n != 0 {
+		t.Fatalf("db2 must not see db1's table (isolation broken), count=%d", n)
+	}
+}
+
+func TestOpen_File_正常(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+
+	path := filepath.Join(t.TempDir(), "cyrene.db")
+	db, err := Open(ctx, path, testLogger())
+	if err != nil {
+		t.Fatalf("Open(file) error: %v", err)
+	}
+	defer db.Close()
+
+	if err := db.PingContext(ctx); err != nil {
+		t.Fatalf("ping file db: %v", err)
+	}
+
+	// Persistence across a reopen with the same DSN.
+	db.ExecContext(ctx, "CREATE TABLE p(x)")
+	db.Close()
+
+	db2, err := Open(ctx, path, testLogger())
+	if err != nil {
+		t.Fatalf("reopen(file) error: %v", err)
+	}
+	defer db2.Close()
+	var n int
+	if err := db2.QueryRowContext(ctx, "SELECT count(*) FROM sqlite_master WHERE name='p'").Scan(&n); err != nil {
+		t.Fatalf("query reopened db: %v", err)
+	}
+	if n != 1 {
+		t.Fatalf("expected table p to persist across reopen, count=%d", n)
+	}
+}
+
+func TestOpen_BlankPath_异常(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+
+	for _, path := range []string{"", "   "} {
+		if _, err := Open(ctx, path, testLogger()); !errors.Is(err, ErrInvalidPath) {
+			t.Fatalf("Open(%q) err = %v, want wrap of ErrInvalidPath", path, err)
+		}
+	}
+}
+
+func TestOpen_MissingParentDir_异常(t *testing.T) {
+	t.Parallel()
+	ctx := context.Background()
+
+	// Parent directory does not exist, so the connection cannot be established.
+	path := filepath.Join(t.TempDir(), "does-not-exist", "cyrene.db")
+	if _, err := Open(ctx, path, testLogger()); err == nil {
+		t.Fatalf("Open(%q) expected error for missing parent dir, got nil", path)
+	}
+}