Ensured that check's required tokens are subset of default tokens, issue #655

src/main/java/com/puppycrawl/tools/checkstyle/TreeWalker.java

@@ -247,6 +247,7 @@ public final class TreeWalker
      */
     private void registerCheck(Check check)
         throws CheckstyleException {
+        validateDefaultTokens(check);
         final int[] tokens;
         final Set<String> checkTokens = check.getTokenNames();
         if (checkTokens.isEmpty()) {
@@ -281,6 +282,24 @@ public final class TreeWalker
         }
     }
 
+    /**
+     * Validates that check's required tokens are subset of default tokens.
+     * @param check to validate
+     * @throws CheckstyleException when validation of default tokens fails
+     */
+    private static void validateDefaultTokens(Check check) throws CheckstyleException {
+        final int[] defaultTokens = check.getDefaultTokens();
+        if (check.getRequiredTokens().length != 0) {
+            Arrays.sort(defaultTokens);
+            for (final int token : check.getRequiredTokens()) {
+                if (Arrays.binarySearch(defaultTokens, token) < 0) {
+                    throw new CheckstyleException("Token \"" + token + "\" from required tokens was"
+                        + " not found in default tokens list in check " + check);
+                }
+            }
+        }
+    }
+
     /**
      * Register a check for a specified token id.
      * @param tokenID the id of the token

src/test/java/com/puppycrawl/tools/checkstyle/TreeWalkerTest.java

@@ -287,7 +287,41 @@ public class TreeWalkerTest extends BaseCheckTestSupport {
         treeWalker.processFiltered(file, lines);
     }
 
-    private static class BadJavaDocCheck extends Check {
+    @Test
+    public void testRequiredTokenIsNotInDefaultTokens() throws Exception {
+        final DefaultConfiguration checkConfig =
+            createCheckConfig(RequiredTokenIsNotInDefaultsCheck.class);
+        final String pathToEmptyFile = temporaryFolder.newFile("file.java").getPath();
+        final String[] expected = {
+        };
+
+        try {
+            verify(checkConfig, pathToEmptyFile, expected);
+            fail();
+        }
+        catch (CheckstyleException ignored) {
+            //expected
+        }
+    }
+
+    @Test
+    public void testRequiredTokenIsEmptyIntArray() throws Exception {
+        final DefaultConfiguration checkConfig =
+            createCheckConfig(RequiredTokenIsEmptyIntArray.class);
+        final String pathToEmptyFile = temporaryFolder.newFile("file.java").getPath();
+        final String[] expected = {
+        };
+
+        try {
+            verify(checkConfig, pathToEmptyFile, expected);
+        }
+        catch (CheckstyleException ignored) {
+            // unexpected
+            fail();
+        }
+    }
+
+    public static class BadJavaDocCheck extends Check {
         @Override
         public int[] getDefaultTokens() {
             return getAcceptableTokens();
@@ -304,4 +338,38 @@ public class TreeWalkerTest extends BaseCheckTestSupport {
         }
     }
 
+    public static class RequiredTokenIsNotInDefaultsCheck extends Check {
+        @Override
+        public int[] getRequiredTokens() {
+            return new int[] {TokenTypes.ASSIGN};
+        }
+
+        @Override
+        public int[] getDefaultTokens() {
+            return new int[] {TokenTypes.ANNOTATION};
+        }
+
+        @Override
+        public int[] getAcceptableTokens() {
+            return ArrayUtils.EMPTY_INT_ARRAY;
+        }
+    }
+
+    public static class RequiredTokenIsEmptyIntArray extends Check {
+        @Override
+        public int[] getRequiredTokens() {
+            return ArrayUtils.EMPTY_INT_ARRAY;
+        }
+
+        @Override
+        public int[] getDefaultTokens() {
+            return new int[] {TokenTypes.ANNOTATION};
+        }
+
+        @Override
+        public int[] getAcceptableTokens() {
+            return ArrayUtils.EMPTY_INT_ARRAY;
+        }
+    }
+
 }