% Creating a Rename Refactoring Test Case

JUnit tests for the Rename refactoring are located in the
\texttt{org.eclipse.photran.refactoring.tests} plug-in project. A Rename test
has two components:

\begin{enumerate}

\item one or more Fortran files, which contain the code to be refactored, and

\item a JUnit test suite class, which creates tests attempting to rename the
identifiers in that file.

\end{enumerate}

The Fortran files are stored as .f90 files in the \emph{rename-test-code}
folder. The JUnit tests are similarly-named Java classes in the
\texttt{org.eclipse.photran.refactoring.tests.rename} package.

A sample JUnit test suite is the following. The more complex tests follow a
similar structure. Here, the \texttt{vars} array records all of the identifiers
and the line/column positions on which they occur. The test suite constructor
attempts to rename each identifier to \texttt{z} and also to
\texttt{a\_really\_really\_long\_name}.

\shabox{Because our strategy for testing requires the \emph{exact} line and
column position, using tabs instead of spaces for indenting could interfere with
the positioning. Therefore, for testing purposes, test cases (the Fortran test
files) should be indented with \textbf{spaces only}. However, when an actual
Fortran programmer invokes a refactoring through the Eclipse UI, the indentation
with tabs or spaces is not a problem because the Eclipse editor is smart enough
to provide the correct position (based on expanding tabs into spaces
internally). } \\

\begin{lstlisting}[frame=lines]
public class Rename2 extends RenameTestSuite
{
	/////////////////////////////////////////////////////////////////////////
	//
	// RECORD POSITIONS OF ALL IDENTIFIERS IN RENAME2.F90, AND
	// GROUP THEM ACCORDING TO WHICH ONES SHOULD BE RENAMED TOGETHER
	//
	/////////////////////////////////////////////////////////////////////////

	private String filename = "rename2.f90";

	private Ident[] vars = new Ident[]
	{
	    var(filename, "Main", new LineCol[] { lc(2,9), lc(27,13) }),
	    var(filename, "one", new LineCol[] { lc(4,16), lc(12,14), 
		                                       lc(16,11), lc(20,11) }),
	    var(filename, "two", new LineCol[] { lc(5,27), lc(10,13),
		                                       lc(13,14), lc(17,14) }),
	    var(filename, "three", new LineCol[] { lc(6,16), lc(14,9), 
		                                         lc(18,9) }),
	    var(filename, "four", new LineCol[] { lc(10,21), lc(15,14),
		                                        lc(19,14) })
	};

	/////////////////////////////////////////////////////////////////////////
	//
	// TEST CASES
	//
	/////////////////////////////////////////////////////////////////////////

	public static Test suite() throws Exception
	{
	    return new Rename2();
	}

	public Rename2() throws Exception
	{
	    startTests("Renaming program with comments and line continuations");
	    for (String name : new String[] { "z", "a_really_really_long_name" })
	        for (Ident var : vars)
	            addSuccessTests(var, name);
	    endTests();
	}
}
\end{lstlisting}

The \texttt{addSuccessTests} method adds several test cases to the suite: it
simulates the user clicking on each occurrence of the identifier and asking to
rename that instance. (Of course, no matter which occurrence is clicked on, all
instances should be renamed\ldots but this has occasionally not happened.)

If the rename should not have succeeded--that is, a precondition would not be
met--\texttt{addPreconditionTests} should have been called rather than
\texttt{addSuccessTests}. A good testing strategy ensures that a program behaves
correctly: it should do \textbf{only} what it is supposed to do and nothing
more. In our case, it should rename only the identifiers that are affected and
ensure that the other identifiers are left untouched.

\texttt{Rename3} is a slightly more complicated example, which renames
identifiers spanning multiple files. In this case, a large boolean matrix is
used to record which identifiers should be renamable to which other identifiers:

\begin{code}
\begin{lstlisting}
private boolean[][] expectSuccess = new boolean[][]
{
    
/* vvv can be renamed to >>>    myProgram, aRenamed3, bRenamed3, contained, 
/* myProgram */ new boolean[] { false,     true,      true,      true,  ...      
/* aRenamed3 */ new boolean[] { true,      false,     false,     false, ...    
/* bRenamed3 */ new boolean[] { true,      false,     false,     false, ...    
/* contained */ new boolean[] { true,      false,     false,     false, ...    
/* external  */ new boolean[] { false,     false,     false,     false, ...    
/* moduleA   */ new boolean[] { false,     false,     false,     false, ...    
/* aSub1of3  */ new boolean[] { true,      false,     false,     false, ...    
/* aSub2of3  */ new boolean[] { true,      false,     false,     false, ...    
/* aSub3of3  */ new boolean[] { true,      true,      true,      true,  ...    
/* moduleB   */ new boolean[] { false,     false,     false,     false, ...    
/* bSub1of3  */ new boolean[] { true,      true,      true,      true,  ...    
/* bSub2of3  */ new boolean[] { true,      false,     false,     false, ...    
/* bSub3of3  */ new boolean[] { true,      true,      true,      true,  ...    
/* moduleC   */ new boolean[] { false,     false,     false,     false, ...    
/* cSub      */ new boolean[] { true,      true,      true,      true,  ...    
};
\end{lstlisting}
\caption{Partial representation of the boolean matrix in \texttt{Rename3}}
\end{code}