Java: improve inspection messages and fix replacement with tab character

in "Unnecessary Unicode escape sequence" inspection

GitOrigin-RevId: 53cd08d56aba3aa23ab4580ebbaf0c3807a7047b

java/java-analysis-impl/resources/messages/InspectionGadgetsBundle.properties

@@ -1955,7 +1955,7 @@ boolean.parameters.problem.descriptor='public' method <code>#ref()</code> with '
 boolean.parameter.constructor.problem.descriptor='public' constructor <code>#ref()</code> with 'boolean' parameter #loc
 boolean.parameters.constructor.problem.descriptor='public' constructor <code>#ref()</code> with 'boolean' parameters #loc
 boolean.parameter.only.report.multiple.option=Only report methods with multiple boolean parameters
-unnecessary.unicode.escape.display.name=Unnecessary unicode escape sequence
+unnecessary.unicode.escape.display.name=Unnecessary Unicode escape sequence
 unnecessary.unicode.escape.problem.descriptor=Unicode escape sequence <code>#ref</code> can be replaced with ''{0}'' #loc
 unnecessary.unicode.escape.problem.newline.descriptor=Unicode escape sequence <code>#ref</code> can be replaced with a line feed character #loc
 missing.package.info.display.name=Missing 'package-info.java'
@@ -2397,7 +2397,7 @@ swap.equals.fix.family.name=Flip method call
 remove.modifier.fix.family.name=Remove modifier
 shift.out.of.range.fix.family.name=Fix shift value
 unnecessary.unicode.escape.fix.family.name=Replace with character
-unnecessary.unicode.escape.fix.text=Replace with line feed character
+unnecessary.unicode.escape.fix.text=Replace with {0, choice, 1#new line|2#tab|3#space} character
 absolute.alignment.in.user.interface.fix.family.name=Replace with constant
 static.inheritance.fix.family.name=Replace inheritance with qualified reference
 suspicious.to.array.call.fix.family.name=Replace with proper array

java/java-analysis-impl/src/com/siyeh/ig/internationalization/UnnecessaryUnicodeEscapeInspection.java

@@ -16,6 +16,8 @@ import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.PsiDocumentManager;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
+import com.intellij.psi.impl.source.tree.ElementType;
+import com.intellij.psi.util.PsiUtil;
 import com.siyeh.InspectionGadgetsBundle;
 import com.siyeh.ig.BaseInspection;
 import com.siyeh.ig.BaseInspectionVisitor;
@@ -64,10 +66,12 @@ public final class UnnecessaryUnicodeEscapeInspection extends BaseInspection {
 
     @Override
     public @NotNull String getName() {
-      if (c == '\n') {
-        return InspectionGadgetsBundle.message("unnecessary.unicode.escape.fix.text");
-      }
-      return CommonQuickFixBundle.message("fix.replace.with.x", (c == '\t') ? "\\t" : c);
+      return switch (c) {
+        case '\n' -> InspectionGadgetsBundle.message("unnecessary.unicode.escape.fix.text", 1);
+        case '\t' -> InspectionGadgetsBundle.message("unnecessary.unicode.escape.fix.text", 2);
+        case ' ' -> InspectionGadgetsBundle.message("unnecessary.unicode.escape.fix.text", 3);
+        default -> CommonQuickFixBundle.message("fix.replace.with.x", c);
+      };
     }
 
     @Override
@@ -78,7 +82,7 @@ public final class UnnecessaryUnicodeEscapeInspection extends BaseInspection {
     @Override
     protected void applyFix(@NotNull Project project, @NotNull PsiElement startElement, @NotNull ModPsiUpdater updater) {
       Document document = startElement.getContainingFile().getFileDocument();
-      String replacement = c == '\t' ? "\\t" : String.valueOf(c);
+      String replacement = c == '\t' && PsiUtil.isJavaToken(startElement, ElementType.STRING_LITERALS) ? "\\t" : String.valueOf(c);
       document.replaceString(myRangeMarker.getStartOffset(), myRangeMarker.getEndOffset(), replacement);
     }
   }
@@ -126,7 +130,7 @@ public final class UnnecessaryUnicodeEscapeInspection extends BaseInspection {
           final int escapeEnd = nextChar + 4;
           final char d = (char)Integer.parseInt(text.substring(nextChar, escapeEnd), 16);
           if (d == '\uFFFD' || (d == '\\' && detectUnicodeEscape(text, escapeEnd - 1, length) != -1)) {
-            // this character is used as a replacement when a unicode character can't be displayed
+            // this character is used as a replacement when a Unicode character can't be displayed
             // replacing the escape with the character may cause confusion, so ignore it.
             // skip if another escape sequence follows '\' without being properly escaped.
             continue;

java/java-tests/testData/ig/com/siyeh/igtest/internationalization/unnecessary_unicode_escape/afterUnnecessaryEscape.java

@@ -1,6 +1,6 @@
-// "Fix all 'Unnecessary unicode escape sequence' problems in file" "true"
+// "Fix all 'Unnecessary Unicode escape sequence' problems in file" "true"
 class X {
-  void test() {
+	void test() {
     String s = "abcd";
     String t = """
       \t

java/java-tests/testData/ig/com/siyeh/igtest/internationalization/unnecessary_unicode_escape/beforeUnnecessaryEscape.java

@@ -1,6 +1,6 @@
-// "Fix all 'Unnecessary unicode escape sequence' problems in file" "true"
+// "Fix all 'Unnecessary Unicode escape sequence' problems in file" "true"
 class X {
-  void test() {
+\u0009void test() {
     String s = "\u<caret>0061\u0062\u0063\u0064";
     String t = """
       \u0009\u000A""";