eth/tracers: add onlyTopCall option to callTracer #25430 (#1291)

eth/tracers/js/goja.go

@@ -124,7 +124,7 @@ type jsTracer struct {
 // The methods `result` and `fault` are required to be present.
 // The methods `step`, `enter`, and `exit` are optional, but note that
 // `enter` and `exit` always go together.
-func newJsTracer(code string, ctx *tracers.Context, _ json.RawMessage) (tracers.Tracer, error) {
+func newJsTracer(code string, ctx *tracers.Context, cfg json.RawMessage) (tracers.Tracer, error) {
 	if c, ok := assetTracers[code]; ok {
 		code = c
 	}
@@ -176,6 +176,17 @@ func newJsTracer(code string, ctx *tracers.Context, _ json.RawMessage) (tracers.
 	t.exit = exit
 	t.result = result
 	t.fault = fault
+
+	// Pass in config
+	if setup, ok := goja.AssertFunction(obj.Get("setup")); ok {
+		cfgStr := "{}"
+		if cfg != nil {
+			cfgStr = string(cfg)
+		}
+		if _, err := setup(obj, vm.ToValue(cfgStr)); err != nil {
+			return nil, err
+		}
+	}
 	// Setup objects carrying data to JS. These are created once and re-used.
 	t.log = &steplog{
 		vm:       vm,

eth/tracers/js/tracer_test.go

@@ -292,3 +292,33 @@ func TestEnterExit(t *testing.T) {
 		t.Errorf("Number of invocations of enter() and exit() is wrong. Have %s, want %s\n", have, want)
 	}
 }
+
+func TestSetup(t *testing.T) {
+	// Test empty config
+	_, err := newJsTracer(`{setup: function(cfg) { if (cfg !== "{}") { throw("invalid empty config") } }, fault: function() {}, result: function() {}}`, new(tracers.Context), nil)
+	if err != nil {
+		t.Error(err)
+	}
+
+	cfg, err := json.Marshal(map[string]string{"foo": "bar"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Test no setup func
+	_, err = newJsTracer(`{fault: function() {}, result: function() {}}`, new(tracers.Context), cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Test config value
+	tracer, err := newJsTracer("{config: null, setup: function(cfg) { this.config = JSON.parse(cfg) }, step: function() {}, fault: function() {}, result: function() { return this.config.foo }}", new(tracers.Context), cfg)
+	if err != nil {
+		t.Fatal(err)
+	}
+	have, err := tracer.GetResult()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(have) != `"bar"` {
+		t.Errorf("tracer returned wrong result. have: %s, want: \"bar\"\n", string(have))
+	}
+}