Matching declared method name to regex - rascal

Question

I am trying to match a Java method name to a regex, but I'm not sure how to do it in Rascal. I want to match a method whose name starts with test (such as JUnit 3 test cases) and transform it to a JUnit 4 test case, with the #Test annotation and removing the test prefix. My code looks like this:
public tuple[int, CompilationUnit] refactorJUnitTestCaseDeclaration(CompilationUnit cu) {
int total = 0;
println(cu);
CompilationUnit unit = visit(cu) {
case(MethodDeclaration)`public void <Identifier name>() <MethodBody body>`: {
if(/test[A-Z]*/ := name) {
total += 1;
newName = name[4..];
insert (MethodDeclaration)`#Test public void <Identifier newName>() <MethodBody body>`;
};
}
};
return <total, unit>;
}
This code results in the following error:
Expected str, but got Identifier
Is there any way to access the name method identifier as a String, so I can try to match it? If not, whats the best way to accomplish this task?

Answer 1

The regex pattern operator wants to match against strings only, so you have to map the parse tree of name (which is of type Identifier) to a string like so: "<name>".
Similarly, to splice back the new name string into the location of an Identifier you have to map it back to Identifier like so: [Identifier] newName.
The end result looks like this:
public tuple[int, CompilationUnit] refactorJUnitTestCaseDeclaration(CompilationUnit cu) {
int total = 0;
println(cu);
CompilationUnit unit = visit(cu) {
case(MethodDeclaration)`public void <Identifier name>() <MethodBody body>`: {
if(/test[A-Z]*/ := "<name>") {
total += 1;
newName = [Identifier] "<name>"[4..];
insert (MethodDeclaration)`#Test public void <Identifier newName>() <MethodBody body>`;
};
}
};
return <total, unit>;
}
You can also directly match the tail out with a named group:
public tuple[int, CompilationUnit] refactorJUnitTestCaseDeclaration(CompilationUnit cu) {
int total = 0;
println(cu);
CompilationUnit unit = visit(cu) {
case(MethodDeclaration)`public void <Identifier name>() <MethodBody body>`: {
if(/test<rest:[A-Z]*>/ := "<name>") {
total += 1;
newName = [Identifier] rest;
insert (MethodDeclaration)`#Test public void <Identifier newName>() <MethodBody body>`;
};
}
};
return <total, unit>;
}