Print preview not showing if default print is invalid.

chrome/renderer/print_web_view_helper_browsertest.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/print_messages.h"
 #include "chrome/renderer/print_web_view_helper.h"
 #include "chrome/test/base/render_view_test.h"
 #include "printing/print_job_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 327 matching lines @@
       EXPECT_NE(0U, preview_param.a.data_size);
     }
   }
 
   void VerifyPrintFailed(bool did_fail) {
     bool print_failed = (render_thread_.sink().GetUniqueMessageMatching(
         PrintHostMsg_PrintingFailed::ID) != NULL);
     EXPECT_EQ(did_fail, print_failed);
   }
 
+  void VerifyPrintPreviewInvalidPrinterSettings(bool settings_invalid) {
+    bool print_preview_invalid_printer_settings =
+        (render_thread_.sink().GetUniqueMessageMatching(
+            PrintHostMsg_PrintPreviewInvalidPrinterSettings::ID) != NULL);
+    EXPECT_EQ(settings_invalid, print_preview_invalid_printer_settings);
+  }
+
   DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelperPreviewTest);
 };
 
 // Tests that print preview work and sending and receiving messages through
 // that channel all works.
 TEST_F(PrintWebViewHelperPreviewTest, OnPrintPreview) {
   LoadHTML(kHelloWorldHTML);
 
   PrintWebViewHelper::Get(view_)->OnInitiatePrintPreview();
   // Fill in some dummy values.
@@ skipping 63 matching lines @@
 TEST_F(PrintWebViewHelperPreviewTest, OnPrintForPrintPreviewFail) {
   LoadHTML(kPrintPreviewHTML);
 
   // An empty dictionary should fail.
   DictionaryValue empty_dict;
   PrintWebViewHelper::Get(view_)->OnPrintForPrintPreview(empty_dict);
 
   VerifyPrintFailed(true);
   VerifyPagesPrinted(false);
 }
+
+// Tests that printing from invalid printer settings fails and receiving error
+// messages through that channel all works.
+TEST_F(PrintWebViewHelperPreviewTest, OnPrintPreviewInvalidSettingsFail) {

[kmadhusu, 2011/08/26 18:50:40]

You also need a separate test to verify "OnPrintForPrintPreview" failure if the
printer has invalid settings. 

[arthurhsu, 2011/08/29 22:53:16]

Done.

+  LoadHTML(kPrintPreviewHTML);
+
+  PrintWebViewHelper::Get(view_)->OnInitiatePrintPreview();
+
+  // Set mock printer to provide invalid settings.

[kmadhusu, 2011/08/26 18:50:40]

The purpose of orig_params and wrong_params is not clear here. 

How about the following test?

TEST_F(PrintWebViewHelperPreviewTest, OnPrintPreviewInvalidSettingsFail) {
  LoadHTML(kPrintPreviewHTML);

  PrintWebViewHelper::Get(view_)->OnInitiatePrintPreview();

  // Set the mock printer to provide invalid settings.
  render_thread_.printer()->UseInvalidPrinterSettings();

  // Fill in some dummy values.
  DictionaryValue dict;
  CreatePrintSettingsDictionary(&dict);
  PrintWebViewHelper::Get(view_)->OnPrintPreview(dict);

  // We should have received invalid printer settings from |printer_|.
  VerifyPrintPreviewInvalidPrinterSettings(true);

  EXPECT_EQ(0, render_thread_.print_preview_pages_reamining());
  VerifyPrintPreviewFailed(true);
  VerifyPrintPreviewGenerated(false);
  VertifyPagesPrinted(false);   
}

[arthurhsu, 2011/08/29 22:53:16]

Done.

+  PrintMsg_Print_Params orig_params, wrong_params;
+
+  render_thread_.printer()->GetDefaultPrintSettings(&orig_params);
+  render_thread_.printer()->SetBadSettings(true);
+  render_thread_.printer()->SetDefaultPrintSettings(wrong_params);
+  render_thread_.printer()->ResetPrinter();
+
+  // Fill in some dummy values.
+  DictionaryValue dict;
+  CreatePrintSettingsDictionary(&dict);
+  PrintWebViewHelper::Get(view_)->OnPrintPreview(dict);
+
+  VerifyPrintPreviewInvalidPrinterSettings(true);
+  VerifyPrintFailed(false);

[kmadhusu, 2011/08/26 18:50:40]

We are verifying that the print preview failed.

[arthurhsu, 2011/08/29 22:53:16]

Done.

+  VerifyPagesPrinted(false);
+
+  render_thread_.printer()->SetBadSettings(false);
+  render_thread_.printer()->SetDefaultPrintSettings(orig_params);
+  render_thread_.printer()->ResetPrinter();
+}
+
 #endif  // !defined(OS_CHROMEOS)