精简后的项目：仅保留 api/ui 源码、文档、构建依赖

api/log/context.go

@@ -0,0 +1,41 @@
+package log
+
+import (
+	"context"
+	"log/slog"
+)
+
+var defaultLogger *slog.Logger
+
+func init() {
+	defaultLogger = slog.Default()
+}
+
+type loggerKeyType string
+
+const loggerKey loggerKeyType = "logger"
+
+func getLogger(ctx context.Context) *slog.Logger {
+	if ctx == nil {
+		return defaultLogger
+	}
+
+	logger := ctx.Value(loggerKey)
+	if logger == nil {
+		return defaultLogger
+	}
+
+	ret, ok := logger.(*slog.Logger)
+	if !ok {
+		return defaultLogger
+	}
+
+	return ret
+}
+
+// WithAttrs creates a new context containing a new logger with [args] as logging attributes.
+func WithAttrs(ctx context.Context, args ...any) context.Context {
+	old := getLogger(ctx)
+	new := old.With(args...)
+	return context.WithValue(ctx, loggerKey, new)
+}

api/log/context_test.go

@@ -0,0 +1,93 @@
+package log
+
+import (
+	"bytes"
+	"context"
+	"log/slog"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	_ "github.com/photoview/photoview/api/test_utils/flags"
+)
+
+func mockDefaultLogger(t *testing.T) *bytes.Buffer {
+	t.Helper()
+
+	var output bytes.Buffer
+	handler := slog.NewJSONHandler(&output, &slog.HandlerOptions{
+		AddSource: false,
+		Level:     slog.LevelInfo,
+		ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr {
+			// Remove time from the output for predictable test output.
+			if a.Key == slog.TimeKey {
+				return slog.Attr{}
+			}
+			return a
+		},
+	})
+
+	logger := slog.New(handler)
+	oldLogger := defaultLogger
+	defaultLogger = logger
+
+	t.Cleanup(func() {
+		defaultLogger = oldLogger
+	})
+
+	return &output
+}
+
+func TestLogger(t *testing.T) {
+	output := mockDefaultLogger(t)
+
+	Debug(nil, "no_context")
+	Info(nil, "no_context")
+	Warn(nil, "no_context")
+	Error(nil, "no_context")
+
+	bg := context.Background()
+
+	Debug(bg, "bg_context")
+	Info(bg, "bg_context")
+	Warn(bg, "bg_context")
+	Error(bg, "bg_context")
+
+	ctx1 := WithAttrs(context.Background(), "arg1", "value")
+	Debug(ctx1, "with_context_1")
+	Info(ctx1, "with_context_1")
+	Warn(ctx1, "with_context_1")
+	Error(ctx1, "with_context_1")
+
+	ctx2 := WithAttrs(ctx1, "arg2", "value")
+	Debug(ctx2, "with_context_2")
+	Info(ctx2, "with_context_2")
+	Warn(ctx2, "with_context_2")
+	Error(ctx2, "with_context_2")
+
+	Debug(ctx1, "with_context_1")
+	Info(ctx1, "with_context_1")
+	Warn(ctx1, "with_context_1")
+	Error(ctx1, "with_context_1")
+
+	// Debug messages are filtered out due to slog.LevelInfo in mock logger
+	want := `{"level":"INFO","msg":"no_context"}
+{"level":"WARN","msg":"no_context"}
+{"level":"ERROR","msg":"no_context"}
+{"level":"INFO","msg":"bg_context"}
+{"level":"WARN","msg":"bg_context"}
+{"level":"ERROR","msg":"bg_context"}
+{"level":"INFO","msg":"with_context_1","arg1":"value"}
+{"level":"WARN","msg":"with_context_1","arg1":"value"}
+{"level":"ERROR","msg":"with_context_1","arg1":"value"}
+{"level":"INFO","msg":"with_context_2","arg1":"value","arg2":"value"}
+{"level":"WARN","msg":"with_context_2","arg1":"value","arg2":"value"}
+{"level":"ERROR","msg":"with_context_2","arg1":"value","arg2":"value"}
+{"level":"INFO","msg":"with_context_1","arg1":"value"}
+{"level":"WARN","msg":"with_context_1","arg1":"value"}
+{"level":"ERROR","msg":"with_context_1","arg1":"value"}
+`
+	if diff := cmp.Diff(output.String(), want); diff != "" {
+		t.Errorf("diff: (-got, +want)\n%s", diff)
+	}
+
+}

api/log/default.go

@@ -0,0 +1,25 @@
+package log
+
+import (
+	"context"
+)
+
+// Debug logs debug messages.
+func Debug(ctx context.Context, msg string, args ...any) {
+	getLogger(ctx).DebugContext(ctx, msg, args...)
+}
+
+// Info logs info messages.
+func Info(ctx context.Context, msg string, args ...any) {
+	getLogger(ctx).InfoContext(ctx, msg, args...)
+}
+
+// Warn logs warning messages.
+func Warn(ctx context.Context, msg string, args ...any) {
+	getLogger(ctx).WarnContext(ctx, msg, args...)
+}
+
+// Error logs error messages.
+func Error(ctx context.Context, msg string, args ...any) {
+	getLogger(ctx).ErrorContext(ctx, msg, args...)
+}