From 707e36e7d8214ca9748f7b8fc621b334c40736ab Mon Sep 17 00:00:00 2001
From: Dan Lynch <pyramation@gmail.com>
Date: Wed, 7 Jan 2026 01:58:48 +0000
Subject: [PATCH] fix(plpgsql-deparser): fix 2 more failing fixtures (189/190
 now pass)

- Fix cursor declaration syntax: output 'cursor_name CURSOR FOR query' instead of
  'cursor_name refcursor CURSOR FOR query' (fixes plpgsql_transaction-17.sql)
- Fix label placement: output label before DECLARE section, not between DECLARE and BEGIN
  (fixes plpgsql_control-15.sql)
- Fix tagged dollar quote handling in test utils: properly match $ delimiters
- Preserve qualified variable names (lbl.a) in FOR loops

Remaining known failure: plpgsql_varprops-13.sql (nested DECLARE inside FOR loop)
---
 .../__tests__/plpgsql-deparser.test.ts        | 11 +---
 .../plpgsql-deparser/src/plpgsql-deparser.ts  | 58 +++++++++++++------
 packages/plpgsql-deparser/test-utils/index.ts | 32 +++++++---
 3 files changed, 68 insertions(+), 33 deletions(-)

diff --git a/packages/plpgsql-deparser/__tests__/plpgsql-deparser.test.ts b/packages/plpgsql-deparser/__tests__/plpgsql-deparser.test.ts
index 96bf4291..4cc2cd29 100644
--- a/packages/plpgsql-deparser/__tests__/plpgsql-deparser.test.ts
+++ b/packages/plpgsql-deparser/__tests__/plpgsql-deparser.test.ts
@@ -33,18 +33,13 @@ describe('PLpgSQLDeparser', () => {
 
   describe('round-trip tests using generated.json', () => {
     // Known failing fixtures due to pre-existing deparser issues:
-    // - Schema qualification loss (pg_catalog.pg_class%rowtype[] -> pg_class%rowtype[])
-    // - 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
+    // - plpgsql_varprops-13.sql: nested DECLARE inside FOR loop - variables declared inside
+    //   the loop body are hoisted to the top-level DECLARE section, changing semantics
+    //   (variables should be reinitialized on each loop iteration)
     const KNOWN_FAILING_FIXTURES = new Set([
       'plpgsql_varprops-13.sql',
-      'plpgsql_transaction-17.sql',
-      'plpgsql_control-15.sql',
     ]);
 
     it('should round-trip ALL generated fixtures (excluding known failures)', async () => {
diff --git a/packages/plpgsql-deparser/src/plpgsql-deparser.ts b/packages/plpgsql-deparser/src/plpgsql-deparser.ts
index d2444e7c..465db3d8 100644
--- a/packages/plpgsql-deparser/src/plpgsql-deparser.ts
+++ b/packages/plpgsql-deparser/src/plpgsql-deparser.ts
@@ -163,6 +163,18 @@ export class PLpgSQLDeparser {
 
     const parts: string[] = [];
 
+    // Extract label from action block - it should come before DECLARE
+    // In PL/pgSQL, the syntax is: <<label>> DECLARE ... BEGIN ... END label
+    let blockLabel: string | undefined;
+    if (func.action && 'PLpgSQL_stmt_block' in func.action) {
+      blockLabel = func.action.PLpgSQL_stmt_block.label;
+    }
+
+    // Output label before DECLARE if present
+    if (blockLabel) {
+      parts.push(`<<${blockLabel}>>`);
+    }
+
     // Collect loop-introduced variables before generating DECLARE section
     const loopVarLinenos = new Set<number>();
     if (func.action) {
@@ -176,8 +188,9 @@ export class PLpgSQLDeparser {
     }
 
     // Deparse the action block (BEGIN...END)
+    // Pass skipLabel=true since we already output the label
     if (func.action) {
-      parts.push(this.deparseStmt(func.action, context));
+      parts.push(this.deparseStmt(func.action, context, blockLabel ? true : false));
     }
 
     return parts.join(this.options.newline);
@@ -417,6 +430,14 @@ export class PLpgSQLDeparser {
       parts.push(kw('CONSTANT'));
     }
 
+    // Handle cursor declarations - don't output the type for cursors
+    // The syntax is: cursor_name CURSOR FOR query
+    if (v.cursor_explicit_expr) {
+      parts.push(kw('CURSOR FOR'));
+      parts.push(this.deparseExpr(v.cursor_explicit_expr));
+      return parts.join(' ');
+    }
+
     if (v.datatype) {
       parts.push(this.deparseType(v.datatype));
     }
@@ -430,12 +451,6 @@ export class PLpgSQLDeparser {
       parts.push(this.deparseExpr(v.default_val));
     }
 
-    // Handle cursor declarations
-    if (v.cursor_explicit_expr) {
-      parts.push(kw('CURSOR FOR'));
-      parts.push(this.deparseExpr(v.cursor_explicit_expr));
-    }
-
     return parts.join(' ');
   }
 
@@ -484,14 +499,15 @@ export class PLpgSQLDeparser {
 
   /**
    * Deparse a statement node
+   * @param skipLabel - If true, skip outputting the label (used when label is output before DECLARE)
    */
-  private deparseStmt(stmt: PLpgSQLStmtNode, context: PLpgSQLDeparserContext): string {
+  private deparseStmt(stmt: PLpgSQLStmtNode, context: PLpgSQLDeparserContext, skipLabel?: boolean): string {
     const nodeType = Object.keys(stmt)[0];
     const nodeData = (stmt as any)[nodeType];
 
     switch (nodeType) {
       case 'PLpgSQL_stmt_block':
-        return this.deparseBlock(nodeData, context);
+        return this.deparseBlock(nodeData, context, skipLabel);
       case 'PLpgSQL_stmt_assign':
         return this.deparseAssign(nodeData, context);
       case 'PLpgSQL_stmt_if':
@@ -553,13 +569,14 @@ export class PLpgSQLDeparser {
 
   /**
    * Deparse a block statement (BEGIN...END)
+   * @param skipLabel - If true, skip outputting the label (used when label is output before DECLARE)
    */
-  private deparseBlock(block: PLpgSQL_stmt_block, context: PLpgSQLDeparserContext): string {
+  private deparseBlock(block: PLpgSQL_stmt_block, context: PLpgSQLDeparserContext, skipLabel?: boolean): string {
     const kw = this.keyword;
     const parts: string[] = [];
 
-    // Label
-    if (block.label) {
+    // Label - skip if already output before DECLARE
+    if (block.label && !skipLabel) {
       parts.push(`<<${block.label}>>`);
     }
 
@@ -1558,13 +1575,20 @@ export class PLpgSQLDeparser {
     if ('PLpgSQL_row' in datum) {
       const row = datum.PLpgSQL_row;
       // If this is an "(unnamed row)" with fields, expand the fields to get actual variable names
-      if (row.refname === '(unnamed row)' && row.fields && row.fields.length > 0 && context?.datums) {
+      if (row.refname === '(unnamed row)' && row.fields && row.fields.length > 0) {
         const fieldNames = row.fields.map(field => {
+          // If the field name contains a dot (qualified reference like lbl.a), use it directly
+          // This preserves block-qualified variable references
+          if (field.name && field.name.includes('.')) {
+            return field.name;
+          }
           // Try to resolve the varno to get the actual variable name
-          const fieldDatum = context.datums[field.varno];
-          if (fieldDatum) {
-            // Recursively get the name, passing context to resolve parent records
-            return this.deparseDatumName(fieldDatum, context);
+          if (context?.datums) {
+            const fieldDatum = context.datums[field.varno];
+            if (fieldDatum) {
+              // Recursively get the name, passing context to resolve parent records
+              return this.deparseDatumName(fieldDatum, context);
+            }
           }
           // Fall back to the field name if we can't resolve the varno
           return field.name;
diff --git a/packages/plpgsql-deparser/test-utils/index.ts b/packages/plpgsql-deparser/test-utils/index.ts
index f55b9e52..9503d5c0 100644
--- a/packages/plpgsql-deparser/test-utils/index.ts
+++ b/packages/plpgsql-deparser/test-utils/index.ts
@@ -279,15 +279,31 @@ function getErrorMessage(type: ParseErrorType): string {
 }
 
 function extractBodyFromSql(sql: string): { body: string; prefix: string; suffix: string } | null {
-  const dollarQuoteMatch = sql.match(/^([\s\S]*?\$\$)([\s\S]*?)(\$\$[\s\S]*)$/);
-  if (dollarQuoteMatch) {
-    return {
-      prefix: dollarQuoteMatch[1],
-      body: dollarQuoteMatch[2],
-      suffix: dollarQuoteMatch[3],
-    };
+  // Match tagged dollar quotes like $proc$, $body$, $func$, etc. or plain $$
+  // The tag is optional: $tag$ or $$
+  // We need to find the FIRST dollar quote and match it with the LAST occurrence of the same tag
+  const dollarQuoteStartMatch = sql.match(/(\$[\w]*\$)/);
+  if (!dollarQuoteStartMatch) {
+    return null;
   }
-  return null;
+  
+  const tag = dollarQuoteStartMatch[1];
+  const escapedTag = tag.replace(/\$/g, '\\$');
+  
+  // Find the first occurrence of the tag and the last occurrence
+  const firstIndex = sql.indexOf(tag);
+  const lastIndex = sql.lastIndexOf(tag);
+  
+  if (firstIndex === lastIndex) {
+    // Only one occurrence - can't extract body
+    return null;
+  }
+  
+  return {
+    prefix: sql.substring(0, firstIndex + tag.length),
+    body: sql.substring(firstIndex + tag.length, lastIndex),
+    suffix: sql.substring(lastIndex),
+  };
 }
 
 function reconstructSql(originalSql: string, newBody: string): string {