walletdk: browser (js/wasm) wallet bindings

Makefile

@@ -3,7 +3,7 @@
 .PHONY: ast-lint ast-grep-fix
 .PHONY: unit unit-cover unit-race unit-swapruntime check-go-version build install clean release
 .PHONY: build build-swapruntime build-swapclient build-walletdkrpc rpc install install-swapruntime install-walletdkrpc help clean-networks
-.PHONY: mobile mobile-android mobile-ios
+.PHONY: mobile mobile-android mobile-ios wasm-wallet
 .PHONY: systest systest-verbose
 .PHONY: commitmsg-lint commitmsg-fmt commitmsg-reword
 
@@ -449,6 +449,29 @@ mobile-ios: #? Build the iOS .xcframework for sdk/walletdk
 	@$(call print, "Building iOS .xcframework for walletdk.")
 	./sdk/walletdk/mobile/gen_bindings.sh ios
 
+WASM_WALLET_OUT := bin/wasm
+WASMSQLITE_DIR := $(shell $(GOCC) list -m -f '{{.Dir}}' github.com/lightninglabs/go-wasmsqlite 2>/dev/null)
+
+wasm-wallet: #? Build the walletdk browser wasm blob + runtime assets into bin/wasm
+	@$(call print, "Building walletdk browser wasm blob.")
+	$(RM) -r $(WASM_WALLET_OUT)
+	mkdir -p $(WASM_WALLET_OUT)
+	GOOS=js GOARCH=wasm $(GOBUILD) -trimpath -ldflags="-s -w" \
+		-tags="mobile walletdkrpc swapruntime" \
+		-o $(WASM_WALLET_OUT)/walletdk.wasm ./cmd/walletdk-wasm
+	gzip -9 -c $(WASM_WALLET_OUT)/walletdk.wasm \
+		> $(WASM_WALLET_OUT)/walletdk.wasm.gz
+	cp "$$($(GOCC) env GOROOT)/lib/wasm/wasm_exec.js" $(WASM_WALLET_OUT)/
+	cp $(WASMSQLITE_DIR)/assets/sqlite3.js $(WASM_WALLET_OUT)/
+	cp $(WASMSQLITE_DIR)/assets/sqlite3.wasm $(WASM_WALLET_OUT)/
+	cp $(WASMSQLITE_DIR)/assets/sqlite3-opfs-async-proxy.js $(WASM_WALLET_OUT)/
+	cp $(WASMSQLITE_DIR)/bridge/sqlite-bridge.js $(WASM_WALLET_OUT)/
+	cp $(WASMSQLITE_DIR)/bridge/sqlite-worker.js $(WASM_WALLET_OUT)/
+	# The go-wasmsqlite assets are read-only in the module cache; make the
+	# copies writable so re-runs (and callers staging the bundle) aren't
+	# blocked by a read-only destination.
+	chmod -R u+w $(WASM_WALLET_OUT)
+
 install: #? Build and install binaries to GOPATH/bin
 	@$(call print, "Installing binaries.")
 	$(GOINSTALL) -trimpath -tags="$(DEV_TAGS)" $(DEV_LDFLAGS) ./cmd/merge-sql-schemas

btcwbackend/boarding_backend.go

@@ -1,3 +1,5 @@
+//go:build !js || !wasm
+
 package btcwbackend
 
 import (

btcwbackend/chain_backend.go

@@ -1,3 +1,5 @@
+//go:build !js || !wasm
+
 package btcwbackend
 
 import (

btcwbackend/config.go

@@ -1,3 +1,5 @@
+//go:build !js || !wasm
+
 package btcwbackend
 
 import (

btcwbackend/doc.go

@@ -1,3 +1,5 @@
+//go:build !js || !wasm
+
 // Package btcwbackend provides a lightweight in-process Bitcoin wallet backed
 // by LND's btcwallet and a neutrino (BIP 157/158) chain backend. It wraps
 // lnwallet/btcwallet.BtcWallet with a neutrino-based chain.Interface,

btcwbackend/log.go

@@ -1,3 +1,5 @@
+//go:build !js || !wasm
+
 package btcwbackend
 
 // Subsystem defines the logging code for this subsystem.

btcwbackend/neutrino.go

@@ -1,3 +1,5 @@
+//go:build !js || !wasm
+
 package btcwbackend
 
 import (

btcwbackend/wallet.go

@@ -1,3 +1,5 @@
+//go:build !js || !wasm
+
 package btcwbackend
 
 import (

btcwbackend/wasm_stub.go

@@ -0,0 +1,129 @@
+//go:build js && wasm
+
+// Package btcwbackend is unavailable in browser WASM builds.
+package btcwbackend
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/btcsuite/btclog/v2"
+	"github.com/lightninglabs/darepo-client/chainbackends"
+	"github.com/lightninglabs/darepo-client/chainsource"
+	"github.com/lightninglabs/darepo-client/wallet"
+	"github.com/lightninglabs/darepo-client/walletcore"
+	fn "github.com/lightningnetwork/lnd/fn/v2"
+	"github.com/lightningnetwork/lnd/keychain"
+)
+
+const (
+	// Subsystem defines the logging code for this subsystem.
+	Subsystem = "BTCW"
+
+	// DefaultFeeMinUpdateTimeout is the default minimum interval between
+	// fee estimation API queries.
+	DefaultFeeMinUpdateTimeout = 5 * time.Minute
+
+	// DefaultFeeMaxUpdateTimeout is the default maximum interval between
+	// fee estimation API queries.
+	DefaultFeeMaxUpdateTimeout = 20 * time.Minute
+)
+
+// Config holds the configuration for the native neutrino-backed wallet.
+type Config struct {
+	walletcore.Config
+
+	NeutrinoDataDir      string
+	ConnectPeers         []string
+	AddPeers             []string
+	BlockHeadersSource   string
+	FilterHeadersSource  string
+	FeeURL               string
+	FeeMinUpdateTimeout  time.Duration
+	FeeMaxUpdateTimeout  time.Duration
+	PackageSubmitter     chainbackends.PackageSubmitter
+	PersistFilters       bool
+	DisableGlobalLoggers bool
+}
+
+// WithLogger returns a new config with the given logger set.
+func (c Config) WithLogger(log btclog.Logger) Config {
+	c.Log = fn.Some(log)
+
+	return c
+}
+
+// NeutrinoServiceOption configures a NeutrinoService.
+type NeutrinoServiceOption func(*NeutrinoService)
+
+// NeutrinoService is a browser stub for the native neutrino service.
+type NeutrinoService struct{}
+
+// WithoutGlobalDependencyLoggers disables native package-global loggers.
+func WithoutGlobalDependencyLoggers() NeutrinoServiceOption {
+	return func(*NeutrinoService) {}
+}
+
+// NewNeutrinoService reports that neutrino is unavailable in browser builds.
+func NewNeutrinoService(string, *chaincfg.Params, []string, []string, bool,
+	string, string, btclog.Logger,
+	...NeutrinoServiceOption) (*NeutrinoService, error) {
+
+	return nil, fmt.Errorf("btcwallet backend is not available in wasm")
+}
+
+// Start reports that neutrino is unavailable in browser builds.
+func (n *NeutrinoService) Start(context.Context) error {
+	return fmt.Errorf("btcwallet backend is not available in wasm")
+}
+
+// Stop is a no-op for the browser stub.
+func (n *NeutrinoService) Stop() error {
+	return nil
+}
+
+// Wallet is a browser stub for the native neutrino-backed wallet.
+type Wallet struct {
+	walletcore.Wallet
+}
+
+// New reports that btcwallet is unavailable in browser builds.
+func New(Config) (*Wallet, error) {
+	return nil, fmt.Errorf("btcwallet backend is not available in wasm")
+}
+
+// NewWithNeutrino reports that btcwallet is unavailable in browser builds.
+func NewWithNeutrino(Config, *NeutrinoService) (*Wallet, error) {
+	return nil, fmt.Errorf("btcwallet backend is not available in wasm")
+}
+
+// Start reports that btcwallet is unavailable in browser builds.
+func (w *Wallet) Start() error {
+	return fmt.Errorf("btcwallet backend is not available in wasm")
+}
+
+// Stop is a no-op for the browser stub.
+func (w *Wallet) Stop() {}
+
+// BoardingBackend reports that no btcwallet boarding backend exists in WASM.
+func (w *Wallet) BoardingBackend() wallet.BoardingBackend {
+	return nil
+}
+
+// ChainBackend reports that no btcwallet chain backend exists in WASM.
+func (w *Wallet) ChainBackend() chainsource.ChainBackend {
+	return nil
+}
+
+// KeyRing returns the embedded walletcore key ring, if one was set by tests.
+func (w *Wallet) KeyRing() keychain.SecretKeyRing {
+	return w.Wallet.KeyRing
+}
+
+// IsSynced reports that the unavailable browser stub is not synced.
+func (w *Wallet) IsSynced() (bool, int64, error) {
+	return false, 0, fmt.Errorf("btcwallet backend is not available in " +
+		"wasm")
+}