diff --git a/sof-js/src/index.js b/sof-js/src/index.js
index 0265dac..4269ede 100644
--- a/sof-js/src/index.js
+++ b/sof-js/src/index.js
@@ -15,13 +15,17 @@ export function merge(a,b) {
 }
 
 export function row_product(parts) {
-  if(parts.length == 1) {return parts[0]}
+  if (parts.length == 1) {
+    return parts[0];
+  }
+
   let rows = [{}];
   let new_rows = null;
-  parts.forEach((partial_rows) => {
+
+  parts.forEach(partial_rows => {
     new_rows = [];
     partial_rows.forEach((partial_row)=> {
-      rows.forEach((row)=> {
+      rows.forEach(row => {
         new_rows.push(merge(partial_row,row))
       })
     })
@@ -129,10 +133,6 @@ function select(select_expr, node, def) {
   )
 }
 
-function compile(def) {
-  throw new Error('not impl');
-}
-
 // * foreach    / column / [select(..)]   -> foreach select[column, ..]
 // * foreach    / union / [select(..)]     -> foreach select[union, ..]
 // * foreach    / select(..)               -> foreach select[..]
@@ -244,18 +244,15 @@ function collect_columns(acc, def){
     return def.select.reduce((acc, s)=> {
       return collect_columns(acc, s);
     }, acc)
-    break;
   case 'unionAll':
     return def.unionAll.reduce((acc, s)=> {
       return collect_columns(acc, s);
     }, acc)
-    break;
   case 'column':
     return def.column.reduce((acc, c)=> {
       acc.push(c.name || c.path)
       return acc
     }, acc)
-    break;
   default:
     return acc;
   }
diff --git a/sof-js/tests/combination.test.js b/sof-js/tests/combination.test.js
index 98c57a2..91630b7 100644
--- a/sof-js/tests/combination.test.js
+++ b/sof-js/tests/combination.test.js
@@ -13,31 +13,112 @@ start_case('Combinations', 'TBD', resources)
 describe("combinations", () => {
 
   add_test({
-    title: 'select & column',
+    title: 'select',
     view: {
       resource: 'Patient',
-      status: 'active',
-      select: [{column: [{path: 'id', name: 'id'}]}]
+      select: [{
+        select: [{column: [{path: 'id', name: 'id'}]}]
+      }]
     },
     expect: [{id: 'pt1'}, {id: 'pt2'}, {id: 'pt3'}]
   });
 
   add_test({
-    title: 'top level column',
+    title: 'column + select',
     view: {
       resource: 'Patient',
-      status: 'active',
-      select: [{column: [{path: 'id', name: 'id'}]}]
+      select: [{
+        column: [{path: 'id', name: 'column_id'}],
+        select: [
+          {
+            column: [{path: 'id', name: 'select_id'}]
+          }
+        ]
+      }]
     },
-    expect: [{id: 'pt1'}, {id: 'pt2'}, {id: 'pt3'}]
+    expect: [
+      { column_id: "pt1", select_id: "pt1" },
+      { column_id: "pt1", select_id: "pt2" },
+      { column_id: "pt1", select_id: "pt3" },
+      { column_id: "pt2", select_id: "pt1" },
+      { column_id: "pt2", select_id: "pt2" },
+      { column_id: "pt2", select_id: "pt3" },
+      { column_id: "pt3", select_id: "pt1" },
+      { column_id: "pt3", select_id: "pt2" },
+      { column_id: "pt3", select_id: "pt3" },
+    ]
+  });
+
+  add_test({
+    title: 'sibling select',
+    view: {
+      resource: 'Patient',
+      select: [
+        { column: [{path: 'id', name: 'id_1'}] },
+        { column: [{path: 'id', name: 'id_2'}] }
+      ]
+    },
+    expect: [
+      { id_1: "pt1", id_2: "pt1" },
+      { id_1: "pt1", id_2: "pt2" },
+      { id_1: "pt1", id_2: "pt3" },
+      { id_1: "pt2", id_2: "pt1" },
+      { id_1: "pt2", id_2: "pt2" },
+      { id_1: "pt2", id_2: "pt3" },
+      { id_1: "pt3", id_2: "pt1" },
+      { id_1: "pt3", id_2: "pt2" },
+      { id_1: "pt3", id_2: "pt3" },
+    ]
+  });
+
+  add_test({
+    title: 'sibling select inside a select',
+    view: {
+      resource: 'Patient',
+      select: [{
+        select: [
+          { column: [{path: 'id', name: 'id_1'}] },
+          { column: [{path: 'id', name: 'id_2'}] }
+        ]
+      }]
+    },
+    expect: [
+      { id_1: "pt1", id_2: "pt1" },
+      { id_1: "pt1", id_2: "pt2" },
+      { id_1: "pt1", id_2: "pt3" },
+      { id_1: "pt2", id_2: "pt1" },
+      { id_1: "pt2", id_2: "pt2" },
+      { id_1: "pt2", id_2: "pt3" },
+      { id_1: "pt3", id_2: "pt1" },
+      { id_1: "pt3", id_2: "pt2" },
+      { id_1: "pt3", id_2: "pt3" },
+    ]
   });
 
+  add_test({
+    title: 'column + select, with where',
+    view: {
+      resource: 'Patient',
+      select: [{
+        column: [{path: 'id', name: 'column_id'}],
+        select: [
+          { column: [{path: 'id', name: 'select_id'}] }
+        ]
+      }],
+      where: [{ path: "id = 'pt1'" }]
+    },
+    expect: [
+      { column_id: "pt1", select_id: "pt1" }
+    ]
+  });
 
   add_test({
-    title: 'select & select & column',
+    title: 'unionAll + forEach + column + select',
     view: {
       resource: 'Patient',
-      select: [{select: [{column: [{path: 'id', name: 'id'}]}]}]
+      select: [{
+        select: [{column: [{path: 'id', name: 'id'}]}]
+      }]
     },
     expect: [{id: 'pt1'}, {id: 'pt2'}, {id: 'pt3'}]
   });