Quickfix "Wrap with double quotes" properly handles single and double quotes inside JSON string

json/src/com/intellij/json/codeinsight/JsonStandardComplianceInspection.java

@@ -139,15 +139,42 @@ public class JsonStandardComplianceInspection extends LocalInspectionTool {
     @Override
     public void applyFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
       final PsiElement element = descriptor.getPsiElement();
+      final String rawText = element.getText();
       if (element instanceof JsonLiteral || element instanceof JsonReferenceExpression) {
-        final String content = JsonPsiUtil.stripQuotes(element.getText());
+        String content = JsonPsiUtil.stripQuotes(rawText);
+        if (element instanceof JsonStringLiteral && rawText.startsWith("'")) {
+          content = escapeSingleQuotedStringContent(content);
+        }
         // TODO: find out better way to replace element and skip reformatting step afterwards
         final ASTNode replacement = new JsonElementGenerator(project).createValue("\"" + content + "\"").getNode();
         element.getParent().getNode().replaceChild(element.getNode(), replacement);
       }
       else if (element != null) {
-        LOG.error("Quick fix was applied to unexpected element", element.getText(), element.getParent().getText());
+        LOG.error("Quick fix was applied to unexpected element", rawText, element.getParent().getText());
       }
     }
+
+    @NotNull
+    private static String escapeSingleQuotedStringContent(@NotNull String content) {
+      final StringBuilder result = new StringBuilder();
+      boolean nextCharEscaped = false;
+      for (int i = 0; i < content.length(); i++) {
+        final char c = content.charAt(i);
+        if ((nextCharEscaped && c != '\'') || (!nextCharEscaped && c == '"')) {
+          result.append('\\');
+        }
+        if (c != '\\' || nextCharEscaped) {
+          result.append(c);
+          nextCharEscaped = false;
+        }
+        else {
+          nextCharEscaped = true;
+        }
+      }
+      if (nextCharEscaped) {
+        result.append('\\');
+      }
+      return result.toString();
+    }
   }
 }

json/tests/test/com/intellij/json/JsonQuickFixTest.java

@@ -30,6 +30,7 @@ public class JsonQuickFixTest extends JsonTestCase {
     checkWrapInDoubleQuotes("'foo\\\"", "\"foo\\\"\"");
     checkWrapInDoubleQuotes("{\"foo\": b<caret>ar}", "{\"foo\": \"bar\"}");
     checkWrapInDoubleQuotes("{\"foo\": 'b<caret>ar'}", "{\"foo\": \"bar\"}");
+    checkWrapInDoubleQuotes("'foo\\n\\'\"\\\\\\\"bar", "\"foo\\n'\\\"\\\\\\\"bar\"");
   }
 
   private void checkWrapInDoubleQuotes(@NotNull String before, @NotNull String after) {