Remove unused local variables despite potential side effects after re…

…moving feature flag (#35) * feat(test): added failing test for RemoveUnusedLocalVariables * Enable removal of local variables with side effects * Repeat removal of unused local variables if needed --------- Co-authored-by: Shannon Pamperl <[email protected]> Co-authored-by: Tim te Beek <[email protected]>
openrewrite · Oct 23, 2024 · e481645 · e481645
1 parent 91d1862
commit e481645
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Showing 3 changed files with 83 additions and 2 deletions.
diff --git a/src/main/java/org/openrewrite/featureflags/RemoveBooleanFlag.java b/src/main/java/org/openrewrite/featureflags/RemoveBooleanFlag.java
@@ -70,7 +70,7 @@ public J visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx)
                 J.MethodInvocation mi = (J.MethodInvocation) super.visitMethodInvocation(method, ctx);
                 if (methodMatcher.matches(mi) && isFeatureKey(mi.getArguments().get(0))) {
                     doAfterVisit(new SimplifyConstantIfBranchExecution().getVisitor());
-                    doAfterVisit(new RemoveUnusedLocalVariables(null, null).getVisitor());
+                    doAfterVisit(Repeat.repeatUntilStable(new RemoveUnusedLocalVariables(null, true).getVisitor(), 3));
                     doAfterVisit(new RemoveUnusedPrivateFields().getVisitor());
                     J.Literal literal = new J.Literal(Tree.randomId(), Space.SINGLE_SPACE, Markers.EMPTY, replacementValue, String.valueOf(replacementValue), null, JavaType.Primitive.Boolean);
                     return literal.withPrefix(mi.getPrefix());

diff --git a/src/main/java/org/openrewrite/featureflags/RemoveStringFlag.java b/src/main/java/org/openrewrite/featureflags/RemoveStringFlag.java
@@ -70,7 +70,7 @@ public J visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx)
                 J.MethodInvocation mi = (J.MethodInvocation) super.visitMethodInvocation(method, ctx);
                 if (methodMatcher.matches(mi) && isFeatureKey(mi.getArguments().get(0))) {
                     doAfterVisit(new SimplifyConstantIfBranchExecution().getVisitor());
-                    doAfterVisit(new RemoveUnusedLocalVariables(null, null).getVisitor());
+                    doAfterVisit(Repeat.repeatUntilStable(new RemoveUnusedLocalVariables(null, true).getVisitor(), 3));
                     doAfterVisit(new RemoveUnusedPrivateFields().getVisitor());
                     J.Literal literal = new J.Literal(Tree.randomId(), Space.SINGLE_SPACE, Markers.EMPTY, replacementValue, '"' + replacementValue + '"', null, JavaType.Primitive.String);
                     return literal.withPrefix(mi.getPrefix());

diff --git a/src/test/java/org/openrewrite/featureflags/launchdarkly/RemoveBoolVariationTest.java b/src/test/java/org/openrewrite/featureflags/launchdarkly/RemoveBoolVariationTest.java
@@ -178,6 +178,87 @@ void bar() {
         );
     }
 
+    @Test
+    void removeUnusedLDContextWithBuilder() {
+        rewriteRun(
+          // language=java
+          java(
+            """
+              import com.launchdarkly.sdk.*;
+              import com.launchdarkly.sdk.server.*;
+              class Foo {
+                  LDClient client = new LDClient("sdk-key-123abc");
+                  void bar() {
+                      LDContext context = LDContext.builder("context-key-123abc")
+                        .name("Sandy")
+                        .build();
+                      if (client.boolVariation("flag-key-123abc", context, false)) {
+                          // Application code to show the feature
+                          System.out.println("Feature is on");
+                      }
+                      else {
+                        // The code to run if the feature is off
+                          System.out.println("Feature is off");
+                      }
+                  }
+              }
+              """,
+            """
+              import com.launchdarkly.sdk.server.*;
+              class Foo {
+                  LDClient client = new LDClient("sdk-key-123abc");
+                  void bar() {
+                      // Application code to show the feature
+                      System.out.println("Feature is on");
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void removeUnusedLDContextWithBuilderContext() {
+        rewriteRun(
+          // language=java
+          java(
+            """
+              import com.launchdarkly.sdk.*;
+              import com.launchdarkly.sdk.server.*;
+              class Foo {
+                  LDClient client = new LDClient("sdk-key-123abc");
+                  void bar() {
+                      LDContext ldContext = LDContext.create("newValue");
+                      LDContext context = LDContext.builderFromContext(ldContext)
+                                .anonymous(false)
+                                .name("name")
+                                .set("email", "[email protected]")
+                                .build();
+                      if (client.boolVariation("flag-key-123abc", context, false)) {
+                          // Application code to show the feature
+                          System.out.println("Feature is on");
+                      }
+                      else {
+                        // The code to run if the feature is off
+                          System.out.println("Feature is off");
+                      }
+                  }
+              }
+              """,
+            """
+              import com.launchdarkly.sdk.server.*;
+              class Foo {
+                  LDClient client = new LDClient("sdk-key-123abc");
+                  void bar() {
+                      // Application code to show the feature
+                      System.out.println("Feature is on");
+                  }
+              }
+              """
+          )
+        );
+    }
+
     @Test
     void enablePermanentlyWithParameters() {
         rewriteRun(