Add error handling to wildcard selectors

This allows us to: - Better handle extension errors - Leaves the decision of handling to Goja when an element is not found. This is how it's done in the k6-core and other extensions. Updates: #804 Related: #688
grafana · Mar 9, 2023 · 7b5f51f · 7b5f51f
1 parent 07526fb
commit 7b5f51f
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Showing 10 changed files with 145 additions and 94 deletions.
diff --git a/api/element_handle.go b/api/element_handle.go
@@ -27,8 +27,8 @@ type ElementHandle interface {
 	IsVisible() bool
 	OwnerFrame() Frame
 	Press(key string, opts goja.Value)
-	Query(selector string) ElementHandle
-	QueryAll(selector string) []ElementHandle
+	Query(selector string) (ElementHandle, error)
+	QueryAll(selector string) ([]ElementHandle, error)
 	Screenshot(opts goja.Value) goja.ArrayBuffer
 	ScrollIntoViewIfNeeded(opts goja.Value)
 	SelectOption(values goja.Value, opts goja.Value) []string

diff --git a/api/frame.go b/api/frame.go
@@ -35,8 +35,8 @@ type Frame interface {
 	// Locator creates and returns a new locator for this frame.
 	Locator(selector string, opts goja.Value) Locator
 	Name() string
-	Query(selector string) ElementHandle
-	QueryAll(selector string) []ElementHandle
+	Query(selector string) (ElementHandle, error)
+	QueryAll(selector string) ([]ElementHandle, error)
 	Page() Page
 	ParentFrame() Frame
 	Press(selector string, key string, opts goja.Value)

diff --git a/api/page.go b/api/page.go
@@ -51,8 +51,8 @@ type Page interface {
 	Pause()
 	Pdf(opts goja.Value) []byte
 	Press(selector string, key string, opts goja.Value)
-	Query(selector string) ElementHandle
-	QueryAll(selector string) []ElementHandle
+	Query(selector string) (ElementHandle, error)
+	QueryAll(selector string) ([]ElementHandle, error)
 	Reload(opts goja.Value) Response
 	Route(url goja.Value, handler goja.Callable)
 	Screenshot(opts goja.Value) goja.ArrayBuffer

diff --git a/browser/mapping.go b/browser/mapping.go
@@ -245,21 +245,25 @@ func mapElementHandle(vu moduleVU, eh api.ElementHandle) mapping {
 			return rt.ToValue(ehm).ToObject(rt)
 		},
 	}
-	maps["$"] = func(selector string) *goja.Object {
-		eh := eh.Query(selector)
+	maps["$"] = func(selector string) (mapping, error) {
+		eh, err := eh.Query(selector)
+		if err != nil {
+			return nil, err //nolint:wrapcheck
+		}
 		ehm := mapElementHandle(vu, eh)
-		return rt.ToValue(ehm).ToObject(rt)
+		return ehm, nil
 	}
-	maps["$$"] = func(selector string) *goja.Object {
-		var (
-			mehs []mapping
-			ehs  = eh.QueryAll(selector)
-		)
+	maps["$$"] = func(selector string) ([]mapping, error) {
+		ehs, err := eh.QueryAll(selector)
+		if err != nil {
+			return nil, err //nolint:wrapcheck
+		}
+		var mehs []mapping
 		for _, eh := range ehs {
 			ehm := mapElementHandle(vu, eh)
 			mehs = append(mehs, ehm)
 		}
-		return rt.ToValue(mehs).ToObject(rt)
+		return mehs, nil
 	}
 
 	jsHandleMap := mapJSHandle(vu, eh)
@@ -377,21 +381,25 @@ func mapFrame(vu moduleVU, f api.Frame) mapping {
 		},
 		"waitForTimeout": f.WaitForTimeout,
 	}
-	maps["$"] = func(selector string) *goja.Object {
-		eh := f.Query(selector)
+	maps["$"] = func(selector string) (mapping, error) {
+		eh, err := f.Query(selector)
+		if err != nil {
+			return nil, err //nolint:wrapcheck
+		}
 		ehm := mapElementHandle(vu, eh)
-		return rt.ToValue(ehm).ToObject(rt)
+		return ehm, nil
 	}
-	maps["$$"] = func(selector string) *goja.Object {
-		var (
-			mehs []mapping
-			ehs  = f.QueryAll(selector)
-		)
+	maps["$$"] = func(selector string) ([]mapping, error) {
+		ehs, err := f.QueryAll(selector)
+		if err != nil {
+			return nil, err //nolint:wrapcheck
+		}
+		var mehs []mapping
 		for _, eh := range ehs {
 			ehm := mapElementHandle(vu, eh)
 			mehs = append(mehs, ehm)
 		}
-		return rt.ToValue(mehs).ToObject(rt)
+		return mehs, nil
 	}
 
 	return maps
@@ -540,21 +548,25 @@ func mapPage(vu moduleVU, p api.Page) mapping {
 			return rt.ToValue(mws).ToObject(rt)
 		},
 	}
-	maps["$"] = func(selector string) *goja.Object {
-		eh := p.Query(selector)
+	maps["$"] = func(selector string) (mapping, error) {
+		eh, err := p.Query(selector)
+		if err != nil {
+			return nil, err //nolint:wrapcheck
+		}
 		ehm := mapElementHandle(vu, eh)
-		return rt.ToValue(ehm).ToObject(rt)
+		return ehm, nil
 	}
-	maps["$$"] = func(selector string) *goja.Object {
-		var (
-			mehs []mapping
-			ehs  = p.QueryAll(selector)
-		)
+	maps["$$"] = func(selector string) ([]mapping, error) {
+		ehs, err := p.QueryAll(selector)
+		if err != nil {
+			return nil, err //nolint:wrapcheck
+		}
+		var mehs []mapping
 		for _, eh := range ehs {
 			ehm := mapElementHandle(vu, eh)
 			mehs = append(mehs, ehm)
 		}
-		return rt.ToValue(mehs).ToObject(rt)
+		return mehs, nil
 	}
 
 	return maps

diff --git a/common/element_handle.go b/common/element_handle.go
@@ -1023,7 +1023,7 @@ func (h *ElementHandle) Press(key string, opts goja.Value) {
 
 // Query runs "element.querySelector" within the page. If no element matches the selector,
 // the return value resolves to "null".
-func (h *ElementHandle) Query(selector string) api.ElementHandle {
+func (h *ElementHandle) Query(selector string) (api.ElementHandle, error) {
 	parsedSelector, err := NewSelector(selector)
 	if err != nil {
 		k6ext.Panic(h.ctx, "parsing selector %q: %w", selector, err)
@@ -1039,35 +1039,35 @@ func (h *ElementHandle) Query(selector string) api.ElementHandle {
 	}
 	result, err := h.evalWithScript(h.ctx, opts, fn, parsedSelector)
 	if err != nil {
-		k6ext.Panic(h.ctx, "querying selector %q: %w", selector, err)
+		return nil, fmt.Errorf("querying selector %q: %w", selector, err)
 	}
 	if result == nil {
-		return nil
+		return nil, fmt.Errorf("querying selector %q", selector)
 	}
-
-	var (
-		handle  = result.(api.JSHandle)
-		element = handle.AsElement()
-	)
-	applySlowMo(h.ctx)
-	if element != nil {
-		return element
+	handle, ok := result.(api.JSHandle)
+	if !ok {
+		return nil, fmt.Errorf("querying selector %q, wrong type %T", selector, result)
 	}
-	handle.Dispose()
-	return nil
+	element := handle.AsElement()
+	if element == nil {
+		handle.Dispose()
+		return nil, fmt.Errorf("querying selector %q", selector)
+	}
+
+	return element, nil
 }
 
 // QueryAll queries element subtree for matching elements.
 // If no element matches the selector, the return value resolves to "null".
-func (h *ElementHandle) QueryAll(selector string) []api.ElementHandle {
+func (h *ElementHandle) QueryAll(selector string) ([]api.ElementHandle, error) {
 	defer applySlowMo(h.ctx)
 
 	handles, err := h.queryAll(selector, h.evalWithScript)
 	if err != nil {
-		k6ext.Panic(h.ctx, "querying all selector %q: %w", selector, err)
+		return nil, fmt.Errorf("querying all selector %q: %w", selector, err)
 	}
 
-	return handles
+	return handles, err
 }
 
 func (h *ElementHandle) queryAll(selector string, eval evalFunc) ([]api.ElementHandle, error) {

diff --git a/common/frame.go b/common/frame.go
@@ -1304,32 +1304,25 @@ func (f *Frame) Name() string {
 
 // Query runs a selector query against the document tree, returning the first matching element or
 // "null" if no match is found.
-func (f *Frame) Query(selector string) api.ElementHandle {
+func (f *Frame) Query(selector string) (api.ElementHandle, error) {
 	f.log.Debugf("Frame:Query", "fid:%s furl:%q sel:%q", f.ID(), f.URL(), selector)
 
 	document, err := f.document()
 	if err != nil {
 		k6ext.Panic(f.ctx, "getting document: %w", err)
 	}
-	value := document.Query(selector)
-	if value != nil {
-		return value
-	}
-	return nil
+	return document.Query(selector)
 }
 
-func (f *Frame) QueryAll(selector string) []api.ElementHandle {
+// QueryAll runs a selector query against the document tree, returning all matching elements.
+func (f *Frame) QueryAll(selector string) ([]api.ElementHandle, error) {
 	f.log.Debugf("Frame:QueryAll", "fid:%s furl:%q sel:%q", f.ID(), f.URL(), selector)
 
 	document, err := f.document()
 	if err != nil {
 		k6ext.Panic(f.ctx, "getting document: %w", err)
 	}
-	value := document.QueryAll(selector)
-	if value != nil {
-		return value
-	}
-	return nil
+	return document.QueryAll(selector)
 }
 
 // Page returns page that owns frame.

diff --git a/common/page.go b/common/page.go
@@ -675,13 +675,15 @@ func (p *Page) Press(selector string, key string, opts goja.Value) {
 	p.MainFrame().Press(selector, key, opts)
 }
 
-func (p *Page) Query(selector string) api.ElementHandle {
+// Query returns the first element matching the specified selector.
+func (p *Page) Query(selector string) (api.ElementHandle, error) {
 	p.logger.Debugf("Page:Query", "sid:%v selector:%s", p.sessionID(), selector)
 
 	return p.frameManager.MainFrame().Query(selector)
 }
 
-func (p *Page) QueryAll(selector string) []api.ElementHandle {
+// QueryAll returns all elements matching the specified selector.
+func (p *Page) QueryAll(selector string) ([]api.ElementHandle, error) {
 	p.logger.Debugf("Page:QueryAll", "sid:%v selector:%s", p.sessionID(), selector)
 
 	return p.frameManager.MainFrame().QueryAll(selector)