fix: use grid instead of cross product (tested with query containing 2 subqueries)

Author: daphne-sfdc

packages/salesforcedx-vscode-soql/src/commands/dataQuery.ts

@@ -126,10 +126,11 @@ const isSubQueryResult = (
 };
 
 /**
- * Flattens a record into one or more rows.
- * Sub-query results are expanded: each sub-record produces a separate output row.
- * Parent fields are shown only on the first child row; subsequent rows leave them blank,
- * matching the Salesforce CLI display style.
+ * Flattens a record into one or more rows, matching the Salesforce CLI display style.
+ * Each sub-query's first element shares row 0 with the parent fields and other
+ * sub-queries' first elements. Remaining elements ("overflow") are stacked in
+ * subsequent rows in sub-query order, with all other columns blank on those rows.
+ * Total rows = 1 + sum(len - 1) for each sub-query — never a cross-product.
  * When a sub-query has no records the parent row is still emitted with empty sub-columns.
  */
 const flattenRecord = (record: Record<string, unknown>): Record<string, unknown>[] => {
@@ -172,32 +173,25 @@ const flattenRecord = (record: Record<string, unknown>): Record<string, unknown>
     return [baseRow];
   }
 
-  // Cross-product of all sub-query expansions merged with the base row.
-  // Multiple sub-queries in a single SELECT are rare but handled correctly.
-  let rows: Record<string, unknown>[] = [baseRow];
+  // Total rows = 1 + sum of (each sub-query's overflow = length - 1)
+  const totalRows = subQueryExpansions.reduce((sum, exp) => sum + exp.length - 1, 1);
+
+  // Allocate the grid. Row 0 starts with the parent fields.
+  const grid: Record<string, unknown>[] = Array.from({ length: totalRows }, () => ({}));
+  Object.assign(grid[0], baseRow);
+
+  // Place each sub-query: element[0] → row 0, overflow elements → consecutive rows
+  // starting immediately after all previous sub-queries' overflow rows.
+  let overflowStart = 1;
   for (const expansion of subQueryExpansions) {
-    const next: Record<string, unknown>[] = [];
-    for (const existing of rows) {
-      for (const expanded of expansion) {
-        next.push({ ...existing, ...expanded });
-      }
+    Object.assign(grid[0], expansion[0]);
+    for (let j = 1; j < expansion.length; j++) {
+      Object.assign(grid[overflowStart + j - 1], expansion[j]);
     }
-    rows = next;
+    overflowStart += expansion.length - 1;
   }
 
-  // Blank out parent fields on all rows after the first, matching the Salesforce CLI
-  // display style where repeated parent values are omitted for readability.
-  const baseKeys = Object.keys(baseRow);
-  return rows.map((row, i) => {
-    if (i === 0 || baseKeys.length === 0) {
-      return row;
-    }
-    const blanked = { ...row };
-    for (const key of baseKeys) {
-      blanked[key] = '';
-    }
-    return blanked;
-  });
+  return grid;
 };
 
 /**

packages/salesforcedx-vscode-soql/test/jest/commands/dataQuery.test.ts

@@ -446,6 +446,54 @@ describe('DataQuery Pure Functions', () => {
       expect(output).not.toContain('[object Object]');
     });
 
+    it('should stack multiple sub-queries independently (not cross-product)', () => {
+      // 2 Contacts + 3 Assets → 4 rows, not 6
+      const records = [
+        {
+          Id: '001Rt00001iD52NIAS',
+          Contacts: {
+            totalSize: 2,
+            done: true,
+            records: [{ Id: '003a' }, { Id: '003b' }]
+          },
+          Assets: {
+            totalSize: 3,
+            done: true,
+            records: [{ Id: '02i1' }, { Id: '02i2' }, { Id: '02i3' }]
+          }
+        }
+      ];
+      const output = generateTableOutput(records, 'Test Table');
+
+      // Correct columns
+      expect(output).toContain('Contacts.Id');
+      expect(output).toContain('Assets.Id');
+
+      // All sub-records present
+      expect(output).toContain('003a');
+      expect(output).toContain('003b');
+      expect(output).toContain('02i1');
+      expect(output).toContain('02i2');
+      expect(output).toContain('02i3');
+
+      // Parent Id appears exactly once (row 0 only)
+      expect(output.match(/001Rt00001iD52NIAS/g)?.length).toBe(1);
+
+      // No cross-product duplication: each sub-record Id appears exactly once
+      expect(output.match(/003a/g)?.length).toBe(1);
+      expect(output.match(/003b/g)?.length).toBe(1);
+      expect(output.match(/02i1/g)?.length).toBe(1);
+      expect(output.match(/02i2/g)?.length).toBe(1);
+      expect(output.match(/02i3/g)?.length).toBe(1);
+
+      // Exactly 4 data rows: 1 (shared first) + 1 (Contact overflow) + 2 (Asset overflow)
+      // Data rows follow the ─── separator line; count non-empty lines after it.
+      const lines = output.split('\n');
+      const sepIdx = lines.findIndex(line => line.trim().startsWith('─'));
+      const dataLines = lines.slice(sepIdx + 1).filter(line => line.trim().length > 0);
+      expect(dataLines).toHaveLength(4);
+    });
+
     it('should emit the parent row with empty sub-columns when a sub-query has no records', () => {
       const records = [
         { Id: '001a', Name: 'No Contacts', Contacts: { totalSize: 0, done: true, records: [] } },