Throw exception clicking on file upload elements in IE

The WebDriver W3C Specification states that if a user attempts to click a
file upload element (<input type="file">), an error should be returned.
This is consistent with the intended behavior of WebDriver from the start,
which is that to upload a file, one should use sendKeys, not click() on
the input element. This now codifies that behavior with returning an
error. Note that if users have erroneously been using click() with file
upload elements, then using some external library (Robot Framework,
Sikuli, etc.) to handle the resulting file selection dialog, their
code will now break, in that the click() method will throw an exception,
and the element will not be clicked. Those users should update their code
accordingly.

Author: jimevans

cpp/iedriver/CommandHandlers/ClickElementCommandHandler.cpp

@@ -18,6 +18,7 @@
 
 #include "ClickElementCommandHandler.h"
 #include "errorcodes.h"
+#include "logging.h"
 #include "../Browser.h"
 #include "../Element.h"
 #include "../Generated/atoms.h"
@@ -55,6 +56,10 @@ void ClickElementCommandHandler::ExecuteInternal(const IECommandExecutor& execut
     ElementHandle element_wrapper;
     status_code = this->GetElement(executor, element_id, &element_wrapper);
     if (status_code == WD_SUCCESS) {
+      if (this->IsFileUploadElement(element_wrapper)) {
+        response->SetErrorResponse(ERROR_INVALID_ARGUMENT, "Cannot call click on an <input type='file'> element. Use sendKeys to upload files.");
+        return;
+      }
       if (executor.input_manager()->enable_native_events()) {
         if (this->IsOptionElement(element_wrapper)) {
           std::string option_click_error = "";
@@ -238,4 +243,22 @@ int ClickElementCommandHandler::ExecuteAtom(
   return status_code;
 }
 
+bool ClickElementCommandHandler::IsFileUploadElement(ElementHandle element) {
+  CComPtr<IHTMLInputFileElement> file;
+  element->element()->QueryInterface<IHTMLInputFileElement>(&file);
+  CComPtr<IHTMLInputElement> input;
+  element->element()->QueryInterface<IHTMLInputElement>(&input);
+  CComBSTR element_type;
+  if (input) {
+    input->get_type(&element_type);
+    HRESULT hr = element_type.ToLower();
+    if (FAILED(hr)) {
+      LOGHR(WARN, hr) << "Failed converting type attribute of <input> element to lowercase using ToLower() method of BSTR";
+    }
+  }
+  bool is_file_element = (file != NULL) ||
+                         (input != NULL && element_type == L"file");
+  return is_file_element;
+}
+
 } // namespace webdriver

cpp/iedriver/CommandHandlers/ClickElementCommandHandler.h

@@ -36,6 +36,7 @@ class ClickElementCommandHandler : public IECommandHandler {
                        Response* response);
 
  private:
+  bool IsFileUploadElement(ElementHandle element_wrapper);
   bool IsOptionElement(ElementHandle element_wrapper);
   std::wstring GetSyntheticClickAtom();
   std::wstring GetClickAtom();