fix(plpgsql-deparser): unwrap the compiler-generated wrapper block around top-level EXCEPTION blocks

Author: pyramation

__fixtures__/plpgsql-generated/generated.json

@@ -157,6 +157,8 @@
   "plpgsql_deparser_fixes-56.sql": "-- Test 56: RAISE EXCEPTION with a named condition (must stay a bare identifier)\nCREATE FUNCTION test_raise_named_condition() RETURNS void\nLANGUAGE plpgsql AS $$\nBEGIN\n  RAISE EXCEPTION division_by_zero;\nEND$$",
   "plpgsql_deparser_fixes-57.sql": "-- Test 57: Bare RETURN NEXT with OUT parameters (retvarno points at out_param_varno; must stay bare)\nCREATE FUNCTION test_return_next_out_params(OUT x integer, OUT y text) RETURNS SETOF record\nLANGUAGE plpgsql AS $$\nBEGIN\n  FOR i IN 1..5 LOOP\n    x := i;\n    y := 'item_' || i::text;\n    RETURN NEXT;\n  END LOOP;\n  RETURN;\nEND$$",
   "plpgsql_deparser_fixes-58.sql": "-- Test 58: RETURN NEXT with a variable (retvarno must be emitted as the variable name)\nCREATE FUNCTION test_return_next_var() RETURNS SETOF integer\nLANGUAGE plpgsql AS $$\nDECLARE\n  r integer;\nBEGIN\n  FOR r IN SELECT g FROM generate_series(1, 3) g LOOP\n    RETURN NEXT r;\n  END LOOP;\nEND$$",
+  "plpgsql_deparser_fixes-59.sql": "-- Test 59: Top-level block with EXCEPTION clause (compiler wraps it in a synthetic outer block; must not deparse a nested BEGIN)\nCREATE FUNCTION test_toplevel_exception(a numeric, b numeric) RETURNS numeric\nLANGUAGE plpgsql AS $$\nDECLARE\n  v_result numeric;\nBEGIN\n  v_result := a / b;\n  RETURN v_result;\nEXCEPTION\n  WHEN division_by_zero THEN\n    RETURN NULL;\nEND$$",
+  "plpgsql_deparser_fixes-60.sql": "-- Test 60: Explicit nested block with EXCEPTION inside a top-level block (nesting must be preserved)\nCREATE FUNCTION test_explicit_nested_exception(p_id integer) RETURNS text\nLANGUAGE plpgsql AS $$\nDECLARE\n  v_result text;\nBEGIN\n  v_result := 'unknown';\n  BEGIN\n    SELECT status INTO v_result FROM items WHERE id = p_id;\n  EXCEPTION\n    WHEN no_data_found THEN\n      v_result := 'not_found';\n  END;\n  RETURN v_result;\nEND$$",
   "plpgsql_control-1.sql": "--\n-- Tests for PL/pgSQL control structures\n--\n\n-- integer FOR loop\n\ndo $$\nbegin\n  -- basic case\n  for i in 1..3 loop\n    raise notice '1..3: i = %', i;\n  end loop;\n  -- with BY, end matches exactly\n  for i in 1..10 by 3 loop\n    raise notice '1..10 by 3: i = %', i;\n  end loop;\n  -- with BY, end does not match\n  for i in 1..11 by 3 loop\n    raise notice '1..11 by 3: i = %', i;\n  end loop;\n  -- zero iterations\n  for i in 1..0 by 3 loop\n    raise notice '1..0 by 3: i = %', i;\n  end loop;\n  -- REVERSE\n  for i in reverse 10..0 by 3 loop\n    raise notice 'reverse 10..0 by 3: i = %', i;\n  end loop;\n  -- potential overflow\n  for i in 2147483620..2147483647 by 10 loop\n    raise notice '2147483620..2147483647 by 10: i = %', i;\n  end loop;\n  -- potential overflow, reverse direction\n  for i in reverse -2147483620..-2147483647 by 10 loop\n    raise notice 'reverse -2147483620..-2147483647 by 10: i = %', i;\n  end loop;\nend$$",
   "plpgsql_control-2.sql": "-- BY can't be zero or negative\ndo $$\nbegin\n  for i in 1..3 by 0 loop\n    raise notice '1..3 by 0: i = %', i;\n  end loop;\nend$$",
   "plpgsql_control-3.sql": "do $$\nbegin\n  for i in 1..3 by -1 loop\n    raise notice '1..3 by -1: i = %', i;\n  end loop;\nend$$",

__fixtures__/plpgsql/plpgsql_deparser_fixes.sql

@@ -725,3 +725,32 @@ BEGIN
     RETURN NEXT r;
   END LOOP;
 END$$;
+
+-- Test 59: Top-level block with EXCEPTION clause (compiler wraps it in a synthetic outer block; must not deparse a nested BEGIN)
+CREATE FUNCTION test_toplevel_exception(a numeric, b numeric) RETURNS numeric
+LANGUAGE plpgsql AS $$
+DECLARE
+  v_result numeric;
+BEGIN
+  v_result := a / b;
+  RETURN v_result;
+EXCEPTION
+  WHEN division_by_zero THEN
+    RETURN NULL;
+END$$;
+
+-- Test 60: Explicit nested block with EXCEPTION inside a top-level block (nesting must be preserved)
+CREATE FUNCTION test_explicit_nested_exception(p_id integer) RETURNS text
+LANGUAGE plpgsql AS $$
+DECLARE
+  v_result text;
+BEGIN
+  v_result := 'unknown';
+  BEGIN
+    SELECT status INTO v_result FROM items WHERE id = p_id;
+  EXCEPTION
+    WHEN no_data_found THEN
+      v_result := 'not_found';
+  END;
+  RETURN v_result;
+END$$;

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

@@ -238,25 +238,21 @@ END"
 
 exports[`plpgsql-deparser bug fixes SQLSTATE exception conditions should emit SQLSTATE codes with the SQLSTATE keyword 1`] = `
 "BEGIN
-  BEGIN
-      RETURN 1;
-  EXCEPTION
-      WHEN unique_violation OR SQLSTATE '23503' THEN
-        RETURN -1;
-      WHEN SQLSTATE 'P0001' THEN
-        RETURN -2;
-  END;
+  RETURN 1;
+EXCEPTION
+  WHEN unique_violation OR SQLSTATE '23503' THEN
+    RETURN -1;
+  WHEN SQLSTATE 'P0001' THEN
+    RETURN -2;
 END"
 `;
 
 exports[`plpgsql-deparser bug fixes bare RAISE re-throw should keep a bare RAISE bare (not RAISE EXCEPTION;) 1`] = `
 "BEGIN
-  BEGIN
-      PERFORM 1;
-  EXCEPTION
-      WHEN others THEN
-        RAISE;
-  END;
+  PERFORM 1;
+EXCEPTION
+  WHEN others THEN
+    RAISE;
 END"
 `;
 
@@ -370,17 +366,15 @@ END"
 
 exports[`plpgsql-deparser bug fixes deep nesting and sequential blocks should handle block inside exception handler 1`] = `
 "BEGIN
-  BEGIN
-      PERFORM risky();
-  EXCEPTION
-      WHEN others THEN
-        BEGIN
-                PERFORM log_error();
-        EXCEPTION
-                WHEN others THEN
-                  RAISE NOTICE 'even logging failed';
-        END;
-  END;
+  PERFORM risky();
+EXCEPTION
+  WHEN others THEN
+    BEGIN
+          PERFORM log_error();
+    EXCEPTION
+          WHEN others THEN
+            RAISE NOTICE 'even logging failed';
+    END;
 END"
 `;
 
@@ -548,6 +542,33 @@ BEGIN
 END"
 `;
 
+exports[`plpgsql-deparser bug fixes top-level EXCEPTION wrapper block should not emit a nested BEGIN for a top-level block with EXCEPTION 1`] = `
+"DECLARE
+  v_result numeric;
+BEGIN
+  v_result := a / b;
+  RETURN v_result;
+EXCEPTION
+  WHEN division_by_zero THEN
+    RETURN NULL;
+END"
+`;
+
+exports[`plpgsql-deparser bug fixes top-level EXCEPTION wrapper block should preserve an explicit nested block with EXCEPTION 1`] = `
+"DECLARE
+  v_result text;
+BEGIN
+  v_result := 'unknown';
+  BEGIN
+      SELECT status INTO v_result FROM items WHERE id = p_id;
+  EXCEPTION
+      WHEN no_data_found THEN
+        v_result := 'not_found';
+  END;
+  RETURN v_result;
+END"
+`;
+
 exports[`plpgsql-deparser bug fixes untested statement types should handle ASSERT statement 1`] = `
 "BEGIN
   ASSERT p_x > 0, 'x must be positive';