fix(wda): reject missing and invalid element bounds

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+- WDA rejects missing or invalid element bounds and retries selector lookup, preventing stale elements from producing successful taps at `(0, 0)`.
+
 ## [1.1.27] - 2026-09-11
 
 Mostly about **flows that already work on Maestro working the same way here**. One of 1.1.26's selector fixes woke up a parsing bug that had been dormant for months: any `inputText` that named an `id:` stopped finding its field, and because that step usually lives in a shared login sub-flow, whole suites went red on their first command. That is fixed, and so are three places where a Maestro flow was read differently here without a word — `speed:` on scrolls, the `value:` spelling of airplane and dark mode, and an element-relative `point:` on swipes. `addMedia` now takes documents, so a flow can seed a PDF and pick it in the system file picker, and a password passed through a variable no longer ends up in the report. There are no behaviour changes: nothing that passes on 1.1.26 should start failing.

pkg/driver/wda/driver.go

@@ -909,12 +909,17 @@ func (d *Driver) getElementInfo(elemID string) (*core.ElementInfo, error) {
 	}()
 	wg.Wait()
 
+	if rectErr != nil {
+		return nil, fmt.Errorf("element bounds unavailable: %w", rectErr)
+	}
+	if w <= 0 || h <= 0 {
+		return nil, fmt.Errorf("element has invalid bounds: %dx%d", w, h)
+	}
+	info.Bounds = core.Bounds{X: x, Y: y, Width: w, Height: h}
+
 	if textErr == nil {
 		info.Text = text
 	}
-	if rectErr == nil {
-		info.Bounds = core.Bounds{X: x, Y: y, Width: w, Height: h}
-	}
 	if nameErr == nil {
 		info.Class = elemName
 	}
@@ -924,9 +929,6 @@ func (d *Driver) getElementInfo(elemID string) (*core.ElementInfo, error) {
 		// XCUITest says off-screen. Check bounds geometrically — if they're
 		// inside the viewport, override XCUITest and accept the element with
 		// a MatchNote so the report records the override.
-		if rectErr != nil {
-			return nil, fmt.Errorf("element exists but is not visible on screen (no bounds)")
-		}
 		screenW, screenH, sErr := d.screenSize()
 		if sErr != nil {
 			return nil, fmt.Errorf("element exists but is not visible on screen (screen size unavailable)")

pkg/driver/wda/stale_element_test.go

@@ -0,0 +1,110 @@
+package wda
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync/atomic"
+	"testing"
+
+	"github.com/devicelab-dev/maestro-runner/pkg/flow"
+)
+
+func TestTapOnStaleElementRecovery(t *testing.T) {
+	for _, present := range []bool{true, false} {
+		name := "element disappeared"
+		if present {
+			name = "element remains in page source"
+		}
+		t.Run(name, func(t *testing.T) {
+			var reads atomic.Int32
+			taps := make(chan [2]float64, 8)
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.Header().Set("Content-Type", "application/json")
+				switch {
+				case strings.HasSuffix(r.URL.Path, "/element"):
+					jsonResponse(w, map[string]any{"value": map[string]string{"ELEMENT": "stale"}})
+				case strings.Contains(r.URL.Path, "/element/stale/"):
+					w.WriteHeader(http.StatusNotFound)
+					jsonResponse(w, map[string]any{"value": map[string]string{
+						"error": "stale element reference", "message": "element is no longer attached",
+					}})
+				case strings.HasSuffix(r.URL.Path, "/source"):
+					reads.Add(1)
+					source := `<AppiumAUT/>`
+					if present {
+						source = `<AppiumAUT><XCUIElementTypeButton type="XCUIElementTypeButton" label="Cancel" enabled="true" visible="true" x="20" y="60" width="44" height="44"/></AppiumAUT>`
+					}
+					jsonResponse(w, map[string]any{"value": source})
+				case strings.HasSuffix(r.URL.Path, "/wda/tap"):
+					var point struct{ X, Y float64 }
+					if err := json.NewDecoder(r.Body).Decode(&point); err != nil {
+						t.Error(err)
+					}
+					taps <- [2]float64{point.X, point.Y}
+					jsonResponse(w, map[string]any{"value": nil})
+				case strings.HasSuffix(r.URL.Path, "/window/size"):
+					jsonResponse(w, map[string]any{"value": map[string]int{"width": 390, "height": 844}})
+				default:
+					t.Errorf("unexpected request: %s", r.URL.Path)
+					w.WriteHeader(http.StatusNotFound)
+				}
+			}))
+			defer server.Close()
+
+			result := createTestDriver(server).tapOn(&flow.TapOnStep{
+				Selector: flow.Selector{Text: "Cancel"},
+				BaseStep: flow.BaseStep{TimeoutMs: 100},
+			})
+			if result.Success != present {
+				t.Fatalf("success = %v, want %v: %s", result.Success, present, result.Message)
+			}
+			if reads.Load() == 0 {
+				t.Error("stale element must be resolved from a fresh page source")
+			}
+			select {
+			case point := <-taps:
+				if !present || point != [2]float64{42, 82} {
+					t.Errorf("unexpected tap at %v", point)
+				}
+			default:
+				if present {
+					t.Error("expected a tap on the recovered element")
+				}
+			}
+		})
+	}
+}
+
+func TestGetElementInfoRejectsInvalidBounds(t *testing.T) {
+	for _, bounds := range []struct {
+		name          string
+		width, height int
+	}{
+		{"zero width", 0, 44},
+		{"zero height", 44, 0},
+		{"negative width", -1, 44},
+		{"negative height", 44, -1},
+	} {
+		t.Run(bounds.name, func(t *testing.T) {
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.Header().Set("Content-Type", "application/json")
+				switch {
+				case strings.HasSuffix(r.URL.Path, "/rect"):
+					jsonResponse(w, map[string]any{"value": map[string]int{
+						"x": 20, "y": 60, "width": bounds.width, "height": bounds.height,
+					}})
+				case strings.HasSuffix(r.URL.Path, "/displayed"):
+					jsonResponse(w, map[string]any{"value": true})
+				default:
+					jsonResponse(w, map[string]any{"value": "Cancel"})
+				}
+			}))
+			defer server.Close()
+			if _, err := createTestDriver(server).getElementInfo("cancel"); err == nil {
+				t.Error("expected invalid element bounds to be rejected")
+			}
+		})
+	}
+}