JUnit4to5Migration removes junit:junit without adding Jupiter when tests extend junit.framework.TestCase

Hi! Thanks for all the work on these recipes — migrating a 20-year-old codebase with them was genuinely impressive, and this was the one place I got stuck.

org.openrewrite.java.testing.junit5.JUnit4to5Migration removes junit:junit but never adds JUnit Jupiter when a project's tests extend junit.framework.TestCase, leaving a project that no longer compiles. The recipe reports BUILD SUCCESS.

This is squarely within the recipe's own scope: JUnit4to5Migration includes
org.openrewrite.java.testing.junit5.MigrateJUnitTestCase, whose own display name is
"Migrate JUnit 4 TestCase to JUnit Jupiter" and which operates on
junit.framework.TestCase / junit.framework.Assert. Those classes ship inside the
junit:junit 4.x artifact, so this is an ordinary JUnit 4 codebase — no JUnit 3
support is being requested here.

There's also a nasty second-order effect: rewrite:run binds after
process-test-classes, so once the project stops compiling, OpenRewrite can no longer
be run to fix it.

Reproduction — a JUnit 4 project

pom.xml:

<dependencies>
  <dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13.2</version>
    <scope>test</scope>
  </dependency>
</dependencies>

src/test/java/com/example/LegacyTest.java:

package com.example;

import junit.framework.TestCase;

public class LegacyTest extends TestCase {
    public void testAddition() {
        assertEquals(4, 2 + 2);
    }
}

Run:

mvn org.openrewrite.maven:rewrite-maven-plugin:6.46.1:run \
  -Drewrite.recipeArtifactCoordinates=org.openrewrite.recipe:rewrite-testing-frameworks:3.44.0 \
  -Drewrite.activeRecipes=org.openrewrite.java.testing.junit5.JUnit4to5Migration

Actual

[WARNING] Changes have been made to pom.xml by:
[WARNING]     org.openrewrite.java.dependencies.RemoveDependency: {groupId=junit, artifactId=junit}
[WARNING] Changes have been made to src/test/java/com/example/LegacyTest.java by:
[INFO] BUILD SUCCESS

pom.xml afterwards has zero <dependency> elements, while the test source now
imports org.junit.jupiter.api. mvn test-compile:

[ERROR] LegacyTest.java:[3,29] package org.junit.jupiter.api does not exist
[ERROR] LegacyTest.java:[5,1]  static import only from classes and interfaces
[ERROR] LegacyTest.java:[8,6]  cannot find symbol
[ERROR] LegacyTest.java:[10,9] cannot find symbol

A project declaring junit:junit:3.8.2 behaves identically — the dependency version is
not the trigger.

Expected

The composite should leave the project compilable: junit-jupiter added in test scope
when junit:junit is removed and no JUnit 5 dependency is present.

Root cause

AddJupiterDependencies builds its internal AddDependency with
onlyIfUsing = org.junit..*:

$ javap -p -c org.openrewrite.java.testing.junit5.AddJupiterDependencies | grep 'ldc.*String'
...
11: ldc  #37   // String org.junit..*
 4: ldc  #31   // String org.junit.jupiter
 6: ldc  #33   // String junit-jupiter
 8: ldc  #35   // String 5.x

A test that only extends junit.framework.TestCase uses no org.junit.* type, so the
guard never fires. The sibling RemoveDependency: junit:junit in the same recipe list
has no such guard and always runs.

Because AddDependency is a ScanningRecipe, its scanner evaluates the pre-edit LST,
so the fact that MigrateJUnitTestCase / UpdateTestAnnotation later rewrite the
sources to org.junit.jupiter.api.Test doesn't help. Tests annotated with
org.junit.Test match the guard and are unaffected — which is why this only shows up
on the junit.framework.TestCase style.

Suggested fix

Broaden the guard in AddJupiterDependencies so it also matches junit.framework..*
alongside org.junit..*. Happy to open a PR with that plus a test case next to the
existing ones if you think that's the right shape — didn't want to presume, since
making the RemoveDependency conditional instead is also defensible.

Not a duplicate of

I looked for existing reports first:

• #506 — a JUnit 4 project where Jupiter wasn't added; the log there shows
  AddDependency firing correctly with onlyIfUsing=org.junit..*, so the cause was
  different and specific to that project.
• #457 — Mockito / mockito-all ordering, partially addressed in 216983b. Related
  in being another onlyIfUsing sensitivity, different path.
• #1103, #1097, #1110 — same family of "JUnit4to5 leaves X behind",
  different X.
• #1108 — the retained TestCase(String) constructor. Directly adjacent: on this
  repro, adding the dependency by hand then exposes #1108, so a
  junit.framework.TestCase codebase currently needs two manual interventions to get
  through what looks like a single-command migration.

Environment

• rewrite-maven-plugin 6.46.1, rewrite-testing-frameworks 3.44.0 (both from Maven Central)
• JDK 21.0.12.1, Maven 3.9.16, surefire 3.5.4

Found while reviving a 2006 Swing/JDBC desktop application (a German Kindergarten
card-index app recovered from SourceForge CVS) and migrating it from Java 8 to Java 21.
Thanks again for the recipes — the rest of that migration was almost entirely automated.

Start with org.openrewrite.java.testing.junit5.AddJupiterDependencies and the JUnit4to5Migration composition, then inspect the existing tests for this recipe. Reproduce the junit:junit project described in the issue and run mvn test-compile; done means a junit.framework.TestCase migration adds junit-jupiter in test scope and the project remains compilable.