Add Matchers.methodHasNoParameters to disambiguate methodHasParameters()

I'll make methodHasParameters(M, M...) after a JB release.

PiperOrigin-RevId: 438833949

Author: graememorgan

check_api/src/main/java/com/google/errorprone/matchers/JUnitMatchers.java

@@ -29,7 +29,7 @@
 import static com.google.errorprone.matchers.Matchers.hasMethod;
 import static com.google.errorprone.matchers.Matchers.hasModifier;
 import static com.google.errorprone.matchers.Matchers.isSubtypeOf;
-import static com.google.errorprone.matchers.Matchers.methodHasParameters;
+import static com.google.errorprone.matchers.Matchers.methodHasNoParameters;
 import static com.google.errorprone.matchers.Matchers.methodHasVisibility;
 import static com.google.errorprone.matchers.Matchers.methodIsNamed;
 import static com.google.errorprone.matchers.Matchers.methodNameStartsWith;
@@ -144,14 +144,14 @@ private static boolean hasJUnitAttr(MethodSymbol methodSym) {
   public static final Matcher<MethodTree> isJunit3TestCase =
       allOf(
           methodNameStartsWith("test"),
-          methodHasParameters(),
+          methodHasNoParameters(),
           Matchers.<MethodTree>hasModifier(Modifier.PUBLIC),
           methodReturns(VOID_TYPE));
 
   /** Common matcher for possible JUnit setUp/tearDown methods. */
   private static final Matcher<MethodTree> looksLikeJUnitSetUpOrTearDown =
       allOf(
-          methodHasParameters(),
+          methodHasNoParameters(),
           anyOf(
               methodHasVisibility(MethodVisibility.Visibility.PUBLIC),
               methodHasVisibility(MethodVisibility.Visibility.PROTECTED)),

check_api/src/main/java/com/google/errorprone/matchers/Matchers.java

@@ -887,6 +887,11 @@ public static Matcher<MethodTree> methodHasParameters(Matcher<VariableTree>... v
     return methodHasParameters(ImmutableList.copyOf(variableMatcher));
   }
 
+  /** Matches an AST node that represents a method declaration with no parameters. */
+  public static Matcher<MethodTree> methodHasNoParameters() {
+    return methodHasParameters(ImmutableList.of());
+  }
+
   /**
    * Matches an AST node that represents a method declaration, based on the list of
    * variableMatchers. Applies the variableMatcher at index n to the parameter at index n and
@@ -1482,7 +1487,7 @@ public static Matcher<MethodTree> equalsMethodDeclaration() {
       allOf(
           methodIsNamed("toString"),
           methodHasVisibility(Visibility.PUBLIC),
-          methodHasParameters(),
+          methodHasNoParameters(),
           methodReturns(STRING_TYPE));
 
   /** Matches {@link Object#toString} method declaration. */
@@ -1494,7 +1499,7 @@ public static Matcher<MethodTree> toStringMethodDeclaration() {
       allOf(
           methodIsNamed("hashCode"),
           methodHasVisibility(Visibility.PUBLIC),
-          methodHasParameters(),
+          methodHasNoParameters(),
           methodReturns(INT_TYPE));
 
   /** Matches {@code hashCode} method declaration. */

core/src/main/java/com/google/errorprone/bugpatterns/JUnit3TestNotRun.java

@@ -27,7 +27,7 @@
 import static com.google.errorprone.matchers.JUnitMatchers.wouldRunInJUnit4;
 import static com.google.errorprone.matchers.Matchers.allOf;
 import static com.google.errorprone.matchers.Matchers.enclosingClass;
-import static com.google.errorprone.matchers.Matchers.methodHasParameters;
+import static com.google.errorprone.matchers.Matchers.methodHasNoParameters;
 import static com.google.errorprone.matchers.Matchers.methodReturns;
 import static com.google.errorprone.matchers.Matchers.not;
 import static com.google.errorprone.suppliers.Suppliers.VOID_TYPE;
@@ -77,7 +77,7 @@ public final class JUnit3TestNotRun extends BugChecker implements MethodTreeMatc
           enclosingClass(isJUnit3TestClass),
           not(isJunit3TestCase),
           methodReturns(VOID_TYPE),
-          methodHasParameters());
+          methodHasNoParameters());
 
   /**
    * Matches iff: