Remove a very literal change-detector test, and move the comment to the production code (which seems more discoverable).

PiperOrigin-RevId: 627693317

Author: graememorgan

annotations/src/main/java/com/google/errorprone/annotations/CompileTimeConstant.java

@@ -130,5 +130,8 @@
  */
 @Documented
 @Retention(CLASS)
+// TODO(xtof): We'd like to eventually support other cases, but I first need to determine with
+// confidence that the checker can ensure all initializations and assignments to such variables are
+// compile-time-constant.
 @Target({ElementType.PARAMETER, ElementType.FIELD})
 public @interface CompileTimeConstant {}

core/src/test/java/com/google/errorprone/matchers/CompileTimeConstantExpressionMatcherTest.java

@@ -16,19 +16,15 @@
 
 package com.google.errorprone.matchers;
 
-import static com.google.common.truth.Truth.assertThat;
 import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
 import static com.google.errorprone.util.ASTHelpers.getSymbol;
 
 import com.google.errorprone.BugPattern;
 import com.google.errorprone.CompilationTestHelper;
 import com.google.errorprone.VisitorState;
-import com.google.errorprone.annotations.CompileTimeConstant;
 import com.google.errorprone.bugpatterns.BugChecker;
 import com.google.errorprone.bugpatterns.BugChecker.VariableTreeMatcher;
 import com.sun.source.tree.VariableTree;
-import java.lang.annotation.ElementType;
-import java.lang.annotation.Target;
 import javax.lang.model.element.ElementKind;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -170,16 +166,6 @@ public void finalCompileTimeConstantConstructorParameters() {
         .doTest();
   }
 
-  // TODO(xtof): We'd like to eventually support other cases, but I first need
-  // to determine with confidence that the checker can ensure all initializations
-  // and assignments to such variables are compile-time-constant.
-  // For now, the annotation's target is restricted to ElementType.PARAMETER.
-  @Test
-  public void compileTimeConstantAnnotationOnlyAllowedOnParameterOrField() {
-    assertThat(CompileTimeConstant.class.getAnnotation(Target.class).value())
-        .isEqualTo(new ElementType[] {ElementType.PARAMETER, ElementType.FIELD});
-  }
-
   @Test
   public void conditionalExpression() {
     testHelper