fix(plpgsql-deparser): expand PLpgSQL_row fields when refname is '(unnamed row)'

When SELECT INTO targets multiple variables, PostgreSQL creates a PLpgSQL_row
datum with refname '(unnamed row)' and stores the actual variable names in
the fields array with varno references.

This fix modifies deparseDatumName() to:
1. Accept an optional context parameter to access the datums array
2. Check if PLpgSQL_row.refname is '(unnamed row)'
3. If so, expand the fields array by resolving varno references to get
   actual variable names
4. Return the comma-separated list of variable names

All callers of deparseDatumName() have been updated to pass the context
parameter where available.

This fixes the issue where generated PL/pgSQL functions contained
'INTO (unnamed row)' instead of the actual variable names like
'INTO v_rowcount'.

Author: pyramation

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

@@ -172,7 +172,7 @@ BEGIN
       GET DIAGNOSTICS v_rowcount = ;
       v_orders_upserted := v_rowcount;
       v_sql := format('SELECT count(*)::int FROM %I.%I WHERE org_id = $1 AND created_at >= $2 AND created_at < $3', 'app_public', 'app_order');
-      EXECUTE v_sql INTO (unnamed row) USING p_org_id, p_from_ts, p_to_ts;
+      EXECUTE v_sql INTO v_rowcount USING p_org_id, p_from_ts, p_to_ts;
       IF p_debug THEN
             RAISE NOTICE 'dynamic count(app_order)=%', v_rowcount;
       END IF;

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

@@ -142,7 +142,7 @@ begin
           'app_public',
           'app_order'
         );
-      execute v_sql into (unnamed row) using p_org_id, p_from_ts, p_to_ts;
+      execute v_sql into v_rowcount using p_org_id, p_from_ts, p_to_ts;
       if p_debug then
             raise notice 'dynamic count(app_order)=%', v_rowcount;
       end if;
@@ -343,7 +343,7 @@ BEGIN
           'app_public',
           'app_order'
         );
-      EXECUTE v_sql INTO (unnamed row) USING p_org_id, p_from_ts, p_to_ts;
+      EXECUTE v_sql INTO v_rowcount USING p_org_id, p_from_ts, p_to_ts;
       IF p_debug THEN
             RAISE NOTICE 'dynamic count(app_order)=%', v_rowcount;
       END IF;

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

@@ -769,7 +769,7 @@ export class PLpgSQLDeparser {
       parts.push(`<<${fori.label}>>`);
     }
 
-    const varName = fori.var ? this.deparseDatumName(fori.var) : 'i';
+    const varName = fori.var ? this.deparseDatumName(fori.var, context) : 'i';
     const lower = fori.lower ? this.deparseExpr(fori.lower) : '1';
     const upper = fori.upper ? this.deparseExpr(fori.upper) : '10';
 
@@ -810,7 +810,7 @@ export class PLpgSQLDeparser {
       parts.push(`<<${fors.label}>>`);
     }
 
-    const varName = fors.var ? this.deparseDatumName(fors.var) : 'rec';
+    const varName = fors.var ? this.deparseDatumName(fors.var, context) : 'rec';
     const query = fors.query ? this.deparseExpr(fors.query) : '';
     parts.push(`${kw('FOR')} ${varName} ${kw('IN')} ${query} ${kw('LOOP')}`);
 
@@ -841,7 +841,7 @@ export class PLpgSQLDeparser {
       parts.push(`<<${forc.label}>>`);
     }
 
-    const varName = forc.var ? this.deparseDatumName(forc.var) : 'rec';
+    const varName = forc.var ? this.deparseDatumName(forc.var, context) : 'rec';
     const cursorName = this.getVarName(forc.curvar, context);
 
     let forClause = `${kw('FOR')} ${varName} ${kw('IN')} ${cursorName}`;
@@ -1057,7 +1057,7 @@ export class PLpgSQLDeparser {
     let sql = exec.sqlstmt ? this.deparseExpr(exec.sqlstmt) : '';
 
     if (exec.into && exec.target) {
-      const targetName = this.deparseDatumName(exec.target);
+      const targetName = this.deparseDatumName(exec.target, context);
       // Check if the SQL already contains INTO
       if (!sql.toUpperCase().includes(' INTO ')) {
         // Insert INTO clause after SELECT
@@ -1085,7 +1085,7 @@ export class PLpgSQLDeparser {
 
     if (exec.into && exec.target) {
       const strict = exec.strict ? kw('STRICT') + ' ' : '';
-      parts.push(`${kw('INTO')} ${strict}${this.deparseDatumName(exec.target)}`);
+      parts.push(`${kw('INTO')} ${strict}${this.deparseDatumName(exec.target, context)}`);
     }
 
     if (exec.params && exec.params.length > 0) {
@@ -1107,7 +1107,7 @@ export class PLpgSQLDeparser {
       parts.push(`<<${fors.label}>>`);
     }
 
-    const varName = fors.var ? this.deparseDatumName(fors.var) : 'rec';
+    const varName = fors.var ? this.deparseDatumName(fors.var, context) : 'rec';
     let forClause = `${kw('FOR')} ${varName} ${kw('IN EXECUTE')} ${fors.query ? this.deparseExpr(fors.query) : ''}`;
 
     if (fors.params && fors.params.length > 0) {
@@ -1224,7 +1224,7 @@ export class PLpgSQLDeparser {
 
     // INTO target
     if (!fetch.is_move && fetch.target) {
-      parts.push(`${kw('INTO')} ${this.deparseDatumName(fetch.target)}`);
+      parts.push(`${kw('INTO')} ${this.deparseDatumName(fetch.target, context)}`);
     }
 
     return parts.join(' ');
@@ -1304,21 +1304,38 @@ export class PLpgSQLDeparser {
       return `$${varno}`;
     }
 
-    return this.deparseDatumName(datum);
+    return this.deparseDatumName(datum, context);
   }
 
   /**
    * Get the name from a datum
+   * For PLpgSQL_row with refname "(unnamed row)", expand the fields array
+   * to get the actual variable names
    */
-  private deparseDatumName(datum: PLpgSQLDatum): string {
+  private deparseDatumName(datum: PLpgSQLDatum, context?: PLpgSQLDeparserContext): string {
     if ('PLpgSQL_var' in datum) {
       return datum.PLpgSQL_var.refname;
     }
     if ('PLpgSQL_rec' in datum) {
       return datum.PLpgSQL_rec.refname;
     }
     if ('PLpgSQL_row' in datum) {
-      return datum.PLpgSQL_row.refname;
+      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) {
+        const fieldNames = row.fields.map(field => {
+          // Try to resolve the varno to get the actual variable name
+          const fieldDatum = context.datums[field.varno];
+          if (fieldDatum) {
+            // Recursively get the name, but without context to avoid infinite loops
+            return this.deparseDatumName(fieldDatum);
+          }
+          // Fall back to the field name if we can't resolve the varno
+          return field.name;
+        });
+        return fieldNames.join(', ');
+      }
+      return row.refname;
     }
     if ('PLpgSQL_recfield' in datum) {
       return datum.PLpgSQL_recfield.fieldname;