Implement automatic E-prefix detection for escaped string literals

packages/deparser/src/deparser.ts

@@ -1254,18 +1254,18 @@ export class Deparser implements DeparserVisitor {
     } else if (nodeAny.sval !== undefined) {
       if (typeof nodeAny.sval === 'object' && nodeAny.sval !== null) {
         if (nodeAny.sval.sval !== undefined) {
-          return QuoteUtils.escape(nodeAny.sval.sval);
+          return QuoteUtils.formatEString(nodeAny.sval.sval);
         } else if (nodeAny.sval.String && nodeAny.sval.String.sval !== undefined) {
-          return QuoteUtils.escape(nodeAny.sval.String.sval);
+          return QuoteUtils.formatEString(nodeAny.sval.String.sval);
         } else if (Object.keys(nodeAny.sval).length === 0) {
           return "''";
         } else {
-          return QuoteUtils.escape(nodeAny.sval.toString());
+          return QuoteUtils.formatEString(nodeAny.sval.toString());
         }
       } else if (nodeAny.sval === null) {
         return 'NULL';
       } else {
-        return QuoteUtils.escape(nodeAny.sval);
+        return QuoteUtils.formatEString(nodeAny.sval);
       }
     } else if (nodeAny.boolval !== undefined) {
       if (typeof nodeAny.boolval === 'object' && nodeAny.boolval !== null) {
@@ -2014,9 +2014,11 @@ export class Deparser implements DeparserVisitor {
     return caseMap[defName.toLowerCase()] || defName;
   }
 
+
+
   String(node: t.String, context: DeparserContext): string {
     if (context.isStringLiteral || context.isEnumValue) {
-      return `'${node.sval || ''}'`;
+      return QuoteUtils.formatEString(node.sval || '');
     }
 
     const value = node.sval || '';
@@ -6215,8 +6217,7 @@ export class Deparser implements DeparserVisitor {
     if (node.comment === null || node.comment === undefined) {
       output.push('NULL');
     } else if (node.comment) {
-      const escapedComment = node.comment.replace(/'/g, "''");
-      output.push(`'${escapedComment}'`);
+      output.push(QuoteUtils.formatEString(node.comment));
     }
 
     return output.join(' ');

packages/deparser/src/utils/quote-utils.ts

@@ -60,4 +60,43 @@ export class QuoteUtils {
   static escape(literal: string): string {
     return `'${literal.replace(/'/g, "''")}'`;
   }
+
+  /**
+   * Escapes a string value for use in E-prefixed string literals
+   * Handles both backslashes and single quotes properly
+   */
+  static escapeEString(value: string): string {
+    return value.replace(/\\/g, '\\\\').replace(/'/g, "''");
+  }
+
+  /**
+   * Formats a string as an E-prefixed string literal with proper escaping
+   * This wraps the complete E-prefix logic including detection and formatting
+   */
+  static formatEString(value: string): string {
+    const needsEscape = QuoteUtils.needsEscapePrefix(value);
+    if (needsEscape) {
+      const escapedValue = QuoteUtils.escapeEString(value);
+      return `E'${escapedValue}'`;
+    } else {
+      return QuoteUtils.escape(value);
+    }
+  }
+
+  /**
+   * Determines if a string value needs E-prefix for escaped string literals
+   * Detects backslash escape sequences that require E-prefix in PostgreSQL
+   */
+  static needsEscapePrefix(value: string): boolean {
+    if (/^\\x[0-9a-fA-F]+$/i.test(value)) {
+      return false;
+    }
+
+    if (/\\x[0-9a-fA-F]/.test(value) && !/\\[nrtbf\\']/.test(value)) {
+      return false;
+    }
+
+    // Check for common backslash escape sequences that require E-prefix
+    return /\\(?:[nrtbf\\']|u[0-9a-fA-F]{4}|U[0-9a-fA-F]{8}|[0-7]{1,3})/.test(value);
+  }
 }