(Oracles) Testing of Copy/Paste in Office Suites



We can do a quick evaluation of the capabilities of Open Office by comparing its behaviors to Microsoft Office. In doing so, we find a critical difference in how the products handle cutting and pasting text. In MS Office's word processor, users can create huge files by pasting large amounts of text. In OO Writer, you cannot create a file larger than 65,535 characters.

Application Description

OpenOffice.org is a free office suite that includes a word processor, a spreadsheet creator, and a presentation creator. Writer is the word processor component of OpenOffice.org and is used to write and edit text documents.

Microsoft Office 2003 is the most widely used office suite. Word is the word processor component of Office 2003 and can be used to perform the same tasks as Writer.

OpenOffice.org's Writer Microsoft Office 2003 Word


Test Design

In Oracle-based testing, we compare the behavior of the program under test to the behavior of a source we consider accurate (an oracle).

One of the common early tasks when testing a program is a survey of the program's capabilities. You walk through then entire product, trying out each feature to see what the product can do, what it does well, what seems awkward, and what seems obviously unstable.

The tester doing the survey has to constantly evaluate the program: Is this behavior reasonable? Correct? In line with user expectations? A tester who is expert with this type of product will have no problem making these evaluations, but a newcomer needs a reference for guidance. An oracle is one such reference.

Open Office (OO) is an office productivity suite that was designed to compete with Microsoft Office. It makes sense to us to use Office as the reference point when surveying Open Office.

Performing the Test

A survey involves rapid testing of many different features. We focus here on just one part of the survey, evaluation of cutting and pasting.

  1. We use Open OpenOffice.org Writer and Microsoft Word.
  2. In Writer, type a few lines of the character 'a'.
  3. Highlight the characters and use Ctrl-C (Copy) and Ctrl-V (Paste) to fill the document with text.
  4. Repeat step 3 to paste in as many characters as possible:

    This picture shows that Writer has stopped accepting characters on Page 18.

  5. In Word, type a few lines of the character 'a'.
  6. Highlight the characters and use Ctrl-C (Copy) and Ctrl-V (Paste) to fill the document with text.
  7. Repeat step 6 to paste in as many characters as possible:

    We stopped that at page 891. Word will still accept characters.



Writer's character count statistics Word's character count statistics

OpenOffice.org Writer stopped accepting text at 65,535 characters (about 18 pages with size 12 Times New Roman font with standard margins). At the 65,535 character limit, we are unable to add characters by pasting or by typing. We can edit the text already in the document.

Even if the character limit for Writer documents is supposed to be 65,535 characters, this test reveals a separate problem. When pasting text that fills the document, the overflow text was cut off without a warning. The user has thus lost data, without necessarily realizing it.

In Word, we saw a completely different situation. After 890 pages, it was still accepting characters. In fact, we could have kept pasting until the system ran out of memory. There is apparently no limit on the amount of characters that Word will accept.

How is this relevant to oracle-based testing? People often write about oracles as test automation support tools. They can be. But as we see here, even in a simple exploration, an oracle can be a useful supplement to specifications and documentation, or a surrogate for these documents if they are unavailable.

Similar Tests/Additional Notes

The same approach is appropriate for any feature in Writer.

Configuration Notes

Testing OpenOffice.org's Writer v1.1.1 on:



Created 16 July 2004 for the CSTER. Updated December 2004.

All images and written material ©Copyright Sam Oswald 2004

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