fix(plpgsql-deparser): fix EXCEPTION block handling in deparser

The deparser was not outputting EXCEPTION blocks because it was checking for
block.exceptions.exc_list directly, but the parser wraps the exception block
in a PLpgSQL_exception_block wrapper.

This fix handles both the direct and wrapped formats:
- { exc_list: [...] } (direct)
- { PLpgSQL_exception_block: { exc_list: [...] } } (wrapped)

This resolves 12 of the 15 known failing fixtures:
- All 7 plpgsql_trap-* fixtures
- plpgsql_transaction-19.sql, -20.sql, -21.sql
- plpgsql_control-17.sql
- plpgsql_call-44.sql

Only 3 fixtures remain failing (down from 15):
- plpgsql_varprops-13.sql (nested DECLARE inside FOR loop)
- plpgsql_transaction-17.sql (CURSOR FOR loop with EXCEPTION block)
- plpgsql_control-15.sql (labeled block with EXIT statement)

Author: pyramation

packages/plpgsql-deparser/__tests__/__snapshots__/hydrate-demo.test.ts.snap

@@ -190,6 +190,15 @@ BEGIN
       message := format('rollup ok: gross=%s discount=%s tax=%s net=%s (discount_rate=%s tax_rate=%s)', v_gross, v_discount, v_tax, v_net, v_discount_rate, v_tax_rate);
       RETURN NEXT;
       RETURN;
+  EXCEPTION
+      WHEN unique_violation THEN
+        RAISE NOTICE 'unique_violation: %', sqlerrm;
+        RAISE EXCEPTION;
+      WHEN others THEN
+        IF p_debug THEN
+                RAISE NOTICE 'error: % (%:%)', sqlerrm, sqlstate, sqlerrm;
+        END IF;
+        RAISE EXCEPTION;
   END;
   RETURN;
 END$$"

packages/plpgsql-deparser/__tests__/plpgsql-deparser.test.ts

@@ -37,22 +37,14 @@ describe('PLpgSQLDeparser', () => {
     // - Tagged dollar quote reconstruction ($tag$...$tag$ not supported)
     // - Exception block handling issues
     // TODO: Fix these underlying issues and remove from allowlist
+    // Remaining known failing fixtures:
+    // - plpgsql_varprops-13.sql: nested DECLARE inside FOR loop (loop variable scope issue)
+    // - plpgsql_transaction-17.sql: CURSOR FOR loop with EXCEPTION block
+    // - plpgsql_control-15.sql: labeled block with EXIT statement
     const KNOWN_FAILING_FIXTURES = new Set([
       'plpgsql_varprops-13.sql',
-      'plpgsql_trap-1.sql',
-      'plpgsql_trap-2.sql',
-      'plpgsql_trap-3.sql',
-      'plpgsql_trap-4.sql',
-      'plpgsql_trap-5.sql',
-      'plpgsql_trap-6.sql',
-      'plpgsql_trap-7.sql',
       'plpgsql_transaction-17.sql',
-      'plpgsql_transaction-19.sql',
-      'plpgsql_transaction-20.sql',
-      'plpgsql_transaction-21.sql',
       'plpgsql_control-15.sql',
-      'plpgsql_control-17.sql',
-      'plpgsql_call-44.sql',
     ]);
 
     it('should round-trip ALL generated fixtures (excluding known failures)', async () => {

packages/plpgsql-deparser/__tests__/pretty/__snapshots__/plpgsql-pretty.test.ts.snap

@@ -163,6 +163,15 @@ begin
         );
       return next;
       return;
+  exception
+      when unique_violation then
+        raise notice 'unique_violation: %', SQLERRM;
+        raise exception;
+      when others then
+        if p_debug then
+                raise notice 'error: % (%:%)', SQLERRM, SQLSTATE, SQLERRM;
+        end if;
+        raise exception;
   end;
   return;
 end"
@@ -362,6 +371,15 @@ BEGIN
         );
       RETURN NEXT;
       RETURN;
+  EXCEPTION
+      WHEN unique_violation THEN
+        RAISE NOTICE 'unique_violation: %', SQLERRM;
+        RAISE EXCEPTION;
+      WHEN others THEN
+        IF p_debug THEN
+                RAISE NOTICE 'error: % (%:%)', SQLERRM, SQLSTATE, SQLERRM;
+        END IF;
+        RAISE EXCEPTION;
   END;
   RETURN;
 END"

packages/plpgsql-deparser/src/plpgsql-deparser.ts

@@ -575,12 +575,17 @@ export class PLpgSQLDeparser {
     }
 
     // Exception handlers
-    if (block.exceptions?.exc_list) {
+    // The exceptions property can be either:
+    // - { exc_list: [...] } (direct)
+    // - { PLpgSQL_exception_block: { exc_list: [...] } } (wrapped)
+    const excList = block.exceptions?.exc_list || 
+                    (block.exceptions as any)?.PLpgSQL_exception_block?.exc_list;
+    if (excList) {
       parts.push(kw('EXCEPTION'));
-      for (const exc of block.exceptions.exc_list) {
+      for (const exc of excList) {
         if ('PLpgSQL_exception' in exc) {
           const excData = exc.PLpgSQL_exception;
-          const conditions = excData.conditions?.map(c => {
+          const conditions = excData.conditions?.map((c: any) => {
             if ('PLpgSQL_condition' in c) {
               return c.PLpgSQL_condition.condname || c.PLpgSQL_condition.sqlerrstate || 'OTHERS';
             }