backend: WASM 向けのブラウザロガー

Changes

3 changed files (+151/-3)

• go.work.sum
  • @@ -10,6 +10,8 @@ golang.org/x/mod v0.24.0 h1:ZfthKaKaT4NrhGVZHO1/WDTwGES4De8KtWO0SIbNJMU=
    golang.org/x/mod v0.24.0/go.mod h1:IXM97Txy2VM4PJ3gI61r1YEk/gAj6zAHN3AdZt6S9Ww= golang.org/x/sync v0.12.0 h1:MHc5BpPuC30uJk597Ri8TV3CNZcTLu6B6z4lJy+g6Jw= golang.org/x/sync v0.12.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA= + golang.org/x/sync v0.13.0 h1:AauUjRAJ9OSnvULf/ARrrVywoJDy0YS2AwQ98I37610= + golang.org/x/sync v0.13.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA= golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA= golang.org/x/term v0.18.0/go.mod h1:ILwASektA3OnRv7amZ1xhE/KTR+u50pbXfZ03+6Nx58= golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
• packages/backend/wasm/log.go (new)
  • @@ -0,0 +1,147 @@
    + // SPDX-FileCopyrightText: 2025 Shota FUJI <pockawoooh@gmail.com> + // SPDX-License-Identifier: AGPL-3.0-only + + //go:build js && wasm + + package main + + import ( + "context" + "log/slog" + "syscall/js" + ) + + type BrowserConsoleLogHandler struct { + attrs []slog.Attr + group string + parent *BrowserConsoleLogHandler + } + + func NewBrowserConsoleLogHandler() *BrowserConsoleLogHandler { + return &BrowserConsoleLogHandler{ + attrs: nil, + group: "", + parent: nil, + } + } + + func (*BrowserConsoleLogHandler) Enabled(_ context.Context, _ slog.Level) bool { + return true + } + + func newObject() js.Value { + obj := js.Global().Get("Object").Call("create", js.Null()) + return obj + } + + func safeJsValueOf(x slog.Value) js.Value { + switch x.Kind() { + case slog.KindBool: + return js.ValueOf(x.Bool()) + case slog.KindInt64: + return js.ValueOf(x.Int64()) + case slog.KindUint64: + return js.ValueOf(x.Uint64()) + case slog.KindFloat64: + return js.ValueOf(x.Float64()) + case slog.KindGroup: + group := newObject() + for _, g := range x.Group() { + group.Set(g.Key, safeJsValueOf(g.Value)) + } + return group + default: + return js.ValueOf(x.String()) + } + } + + func (h *BrowserConsoleLogHandler) getAttrsObject() (js.Value, js.Value) { + var obj js.Value + var root js.Value + + if h.parent == nil { + root = newObject() + + obj = root + if h.group != "" { + child := newObject() + root.Set(h.group, child) + obj = child + } + + } else { + var parent js.Value + parent, root = h.parent.getAttrsObject() + + obj = parent + if h.group != "" { + child := newObject() + parent.Set(h.group, child) + obj = child + } + } + + if len(h.attrs) == 0 { + return obj, root + } + + for _, attr := range h.attrs { + obj.Set(attr.Key, safeJsValueOf(attr.Value)) + } + + return obj, root + } + + func (h *BrowserConsoleLogHandler) Handle(ctx context.Context, record slog.Record) error { + console := js.Global().Get("console") + + var method string + switch record.Level { + case slog.LevelDebug: + method = "debug" + case slog.LevelInfo: + method = "info" + case slog.LevelWarn: + method = "warn" + case slog.LevelError: + method = "error" + } + + message := record.Message + "\n" + + attrs, attrsRoot := h.getAttrsObject() + + record.Attrs(func(attr slog.Attr) bool { + attrs.Set(attr.Key, safeJsValueOf(attr.Value)) + return true + }) + + properties := js.Global().Get("Object").Call("keys", attrsRoot).Get("length") + if properties.Equal(js.ValueOf(0)) { + console.Call(method, message) + } else { + console.Call(method, message, attrsRoot) + } + + return nil + } + + func (h *BrowserConsoleLogHandler) WithAttrs(attrs []slog.Attr) slog.Handler { + return &BrowserConsoleLogHandler{ + attrs: attrs, + group: "", + parent: h, + } + } + + func (h *BrowserConsoleLogHandler) WithGroup(name string) slog.Handler { + if name == "" { + return h + } + + return &BrowserConsoleLogHandler{ + attrs: nil, + group: name, + parent: h, + } + }
• packages/backend/wasm/wasm.go
  • @@ -18,9 +18,8 @@
    _ "github.com/matrix-org/go-sqlite3-js" ) - // TODO: console のメソッドを使ったロガーを実装する func main() { - logger := slog.Default() + logger := slog.New(NewBrowserConsoleLogHandler()) db, err := sql.Open("sqlite3", "yamori.wasm") if err != nil {
  • @@ -28,7 +27,7 @@ logger.Error("Failed to open database", "error", err)
    os.Exit(2) } - core, err := core.New(db, slog.Default()) + core, err := core.New(db, logger) if err != nil { logger.Error("Failed to create core instance", "error", err) os.Exit(3)