Make EffectivelyPrivate an error

Twelve members of private nested classes were public or protected,
which reaches no further than the file a private class is in. They
have no access modifier now:
- the constructors of Obs's two nodes, of ReferenceScanner, and of the
  test's DelegatingFormatter;
- the IntelliJ formatting task's constructor and applyReplacements;
- SnippetWrapper's three methods and StringWrapper's
  getReflowReplacements;
- TypeNameClassifier's TyParseState.isSingleUnit and next(), with the
  five overrides of next() in its constants.

Author: abashev

buildSrc/src/main/groovy/open-java-format.error-prone-conventions.gradle

@@ -28,6 +28,7 @@ tasks.withType(JavaCompile).configureEach {
         error('CanonicalAnnotationSyntax')
         error('CollectorMutability')
         error('DirectReturn')
+        error('EffectivelyPrivate')
         error('FormatStringConcatenation')
         error('JUnitClassModifiers')
         error('JUnitMethodDeclaration')

open-java-format-eclipse-plugin/src/main/java/com/palantir/javaformat/java/SnippetFormatter.java

@@ -42,18 +42,18 @@ private final class SnippetWrapper {
         int offset;
         final StringBuilder contents = new StringBuilder();
 
-        public SnippetWrapper append(String str) {
+        SnippetWrapper append(String str) {
             contents.append(str);
             return this;
         }
 
-        public SnippetWrapper appendSource(String source) {
+        SnippetWrapper appendSource(String source) {
             this.offset = contents.length();
             contents.append(source);
             return this;
         }
 
-        public void closeBraces(int initialIndent) {
+        void closeBraces(int initialIndent) {
             for (int i = initialIndent; --i >= 0; ) {
                 contents.append("\n").append(createIndentationString(i)).append("}");
             }

open-java-format-idea-plugin/src/main/java/com/palantir/javaformat/intellij/PalantirJavaFormatFormattingService.java

@@ -108,8 +108,7 @@ private static final class PalantirJavaFormatFormattingTask implements Formattin
         private final AsyncFormattingRequest request;
         private final Optional<FormatterService> formatterService;
 
-        public PalantirJavaFormatFormattingTask(
-                AsyncFormattingRequest request, Optional<FormatterService> formatterService) {
+        PalantirJavaFormatFormattingTask(AsyncFormattingRequest request, Optional<FormatterService> formatterService) {
             this.request = request;
             this.formatterService = formatterService;
         }
@@ -174,7 +173,7 @@ public void run() {
             }
         }
 
-        public static String applyReplacements(String input, Collection<Replacement> replacementsCollection) {
+        static String applyReplacements(String input, Collection<Replacement> replacementsCollection) {
             List<Replacement> replacements = new ArrayList<>(replacementsCollection);
             replacements.sort(comparing((Replacement r) -> r.getReplaceRange().lowerEndpoint())
                     .reversed());

open-java-format-idea-plugin/src/test/java/com/palantir/javaformat/intellij/PalantirJavaFormatFormattingServiceTest.java

@@ -126,7 +126,7 @@ private PsiFile createPsiFile(String path, String... contents) throws IOExceptio
     }
 
     private static final class DelegatingFormatter extends PalantirJavaFormatFormattingService {
-        public DelegatingFormatter() {
+        DelegatingFormatter() {
             this.setPluginDescriptor(
                     requireNonNull(FormattingService.EP_NAME.findExtension(PalantirJavaFormatFormattingService.class))
                             .getPluginDescriptor()

open-java-format/src/main/java/com/palantir/javaformat/doc/Obs.java

@@ -95,7 +95,7 @@ private static class LevelNodeImpl extends HasUniqueId implements LevelNode {
         private final FinishLevelNode finisher;
         private final int startColumn;
 
-        public LevelNodeImpl(Level level, State incomingState, int parentExplorationId, Sink sink) {
+        LevelNodeImpl(Level level, State incomingState, int parentExplorationId, Sink sink) {
             this.level = level;
             this.sink = sink;
             this.finisher = sink.writeLevelNode(id(), parentExplorationId, incomingState, level);
@@ -170,7 +170,7 @@ private static class ExplorationNodeImpl extends HasUniqueId implements Explorat
         private final FinishExplorationNode finishExplorationNode;
         private final Optional<Level> parentLevel;
 
-        public ExplorationNodeImpl(
+        ExplorationNodeImpl(
                 @Nullable LevelNodeImpl parent,
                 String humanDescription,
                 Sink sink,

open-java-format/src/main/java/com/palantir/javaformat/java/RemoveUnusedImports.java

@@ -181,7 +181,7 @@ public Void visitReference(ReferenceTree referenceTree, Void unused) {
             private class ReferenceScanner extends TreeScanner<Void, Void> {
                 private final long basePos;
 
-                public ReferenceScanner(long basePos) {
+                ReferenceScanner(long basePos) {
                     this.basePos = basePos;
                 }
 

open-java-format/src/main/java/com/palantir/javaformat/java/StringWrapper.java

@@ -173,7 +173,7 @@ private static class Reflower {
             this.lineMap = unit.getLineMap();
         }
 
-        protected TreeRangeMap<Integer, String> getReflowReplacements() {
+        TreeRangeMap<Integer, String> getReflowReplacements() {
             // Paths to string literals that extend past the column limit.
             List<TreePath> longStringLiterals = new ArrayList<>();
             // Paths to text blocks to be re-indented.

open-java-format/src/main/java/com/palantir/javaformat/java/TypeNameClassifier.java

@@ -29,7 +29,7 @@ private enum TyParseState {
         /** The start state. */
         START(false) {
             @Override
-            public TyParseState next(JavaCaseFormat n) {
+            TyParseState next(JavaCaseFormat n) {
                 return switch (n) {
                     case UPPERCASE ->
                         // if we see an UpperCamel later, assume this was a class
@@ -47,7 +47,7 @@ public TyParseState next(JavaCaseFormat n) {
         /** The current prefix is a type. */
         TYPE(true) {
             @Override
-            public TyParseState next(JavaCaseFormat n) {
+            TyParseState next(JavaCaseFormat n) {
                 return switch (n) {
                     case UPPERCASE, LOWER_CAMEL, LOWERCASE -> TyParseState.FIRST_STATIC_MEMBER;
                     case UPPER_CAMEL -> TyParseState.TYPE;
@@ -58,23 +58,23 @@ public TyParseState next(JavaCaseFormat n) {
         /** The current prefix is a type, followed by a single static member access. */
         FIRST_STATIC_MEMBER(true) {
             @Override
-            public TyParseState next(JavaCaseFormat n) {
+            TyParseState next(JavaCaseFormat n) {
                 return TyParseState.REJECT;
             }
         },
 
         /** Anything not represented by one of the other states. */
         REJECT(false) {
             @Override
-            public TyParseState next(JavaCaseFormat n) {
+            TyParseState next(JavaCaseFormat n) {
                 return TyParseState.REJECT;
             }
         },
 
         /** An ambiguous type prefix. */
         AMBIGUOUS(false) {
             @Override
-            public TyParseState next(JavaCaseFormat n) {
+            TyParseState next(JavaCaseFormat n) {
                 return switch (n) {
                     case UPPERCASE -> AMBIGUOUS;
                     case LOWER_CAMEL, LOWERCASE -> TyParseState.REJECT;
@@ -89,12 +89,12 @@ public TyParseState next(JavaCaseFormat n) {
             this.isSingleUnit = isSingleUnit;
         }
 
-        public boolean isSingleUnit() {
+        boolean isSingleUnit() {
             return isSingleUnit;
         }
 
         /** Transition function. */
-        public abstract TyParseState next(JavaCaseFormat n);
+        abstract TyParseState next(JavaCaseFormat n);
     }
 
     /**