[7.17] [Lens] Fixes error on table when there is no data (#161953) (#…

…162018)

# Backport

This will backport the following commits from `main` to `7.17`:
- [[Lens] Fixes error on table when there is no data
(#161953)](#161953)

<!--- Backport version: 8.9.7 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Stratoula
Kalafateli","email":"efstratia.kalafateli@elastic.co"},"sourceCommit":{"committedDate":"2023-07-17T07:45:22Z","message":"[Lens]
Fixes error on table when there is no data (#161953)\n\n##
Summary\r\n\r\nCloses
#161948 the bug
described in the issue. The bug is happening only for the\r\ntable
viz.\r\n\r\n<img width=\"1664\"
alt=\"image\"\r\nsrc=\"https://github.com/elastic/kibana/assets/17003240/9646edcc-005d-4d2c-919a-097a673d730e\">\r\n\r\n\r\n###
Checklist\r\n\r\n- [ ] [Unit or
functional\r\ntests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)\r\nwere
updated or added to match the most common
scenarios","sha":"6550793b4fe793ad53072bddc51118e43414e7ad","branchLabelMapping":{"^v8.10.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["release_note:fix","Team:Visualizations","Feature:Lens","backport:prev-MAJOR","v8.10.0","v7.17.12"],"number":161953,"url":"#161953
Fixes error on table when there is no data (#161953)\n\n##
Summary\r\n\r\nCloses
#161948 the bug
described in the issue. The bug is happening only for the\r\ntable
viz.\r\n\r\n<img width=\"1664\"
alt=\"image\"\r\nsrc=\"https://github.com/elastic/kibana/assets/17003240/9646edcc-005d-4d2c-919a-097a673d730e\">\r\n\r\n\r\n###
Checklist\r\n\r\n- [ ] [Unit or
functional\r\ntests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)\r\nwere
updated or added to match the most common
scenarios","sha":"6550793b4fe793ad53072bddc51118e43414e7ad"}},"sourceBranch":"main","suggestedTargetBranches":["7.17"],"targetPullRequestStates":[{"branch":"main","label":"v8.10.0","labelRegex":"^v8.10.0$","isSourceBranch":true,"state":"MERGED","url":"#161953
Fixes error on table when there is no data (#161953)\n\n##
Summary\r\n\r\nCloses
#161948 the bug
described in the issue. The bug is happening only for the\r\ntable
viz.\r\n\r\n<img width=\"1664\"
alt=\"image\"\r\nsrc=\"https://github.com/elastic/kibana/assets/17003240/9646edcc-005d-4d2c-919a-097a673d730e\">\r\n\r\n\r\n###
Checklist\r\n\r\n- [ ] [Unit or
functional\r\ntests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)\r\nwere
updated or added to match the most common
scenarios","sha":"6550793b4fe793ad53072bddc51118e43414e7ad"}},{"branch":"7.17","label":"v7.17.12","labelRegex":"^v(\\d+).(\\d+).\\d+$","isSourceBranch":false,"state":"NOT_CREATED"}]}]
BACKPORT-->

Co-authored-by: Stratoula Kalafateli <efstratia.kalafateli@elastic.co>

x-pack/plugins/lens/common/expressions/datatable/transpose_helpers.test.ts

@@ -11,7 +11,7 @@ import { DatatableArgs } from './datatable';
 
 import { transposeTable } from './transpose_helpers';
 
-describe('transpose_helpes', () => {
+describe('transpose_helpers', () => {
   function buildTable(): Datatable {
     // 3 buckets, 2 metrics
     // first bucket goes A/B/C
@@ -290,4 +290,26 @@ describe('transpose_helpes', () => {
       1 + 18 - 2
     );
   });
+
+  it('should not fail for no data', () => {
+    const table = buildTable();
+    const updatedTable = {
+      ...table,
+      rows: [],
+    };
+    const args = buildArgs();
+    const updatedArgs = {
+      ...args,
+      columns: [
+        {
+          type: 'lens_datatable_column',
+          columnId: 'bucket1',
+          isTransposed: true,
+          transposable: false,
+        },
+      ],
+    } as DatatableArgs;
+    transposeTable(updatedArgs, updatedTable, buildFormatters());
+    expect(args.columns.length).toEqual(5);
+  });
 });

x-pack/plugins/lens/common/expressions/datatable/transpose_helpers.ts

@@ -121,7 +121,7 @@ function updateColumnArgs(
 ) {
   args.columns = [...bucketsColumnArgs];
   // add first column from each group, then add second column for each group, ...
-  transposedColumnGroups[0].forEach((_, index) => {
+  transposedColumnGroups[0]?.forEach((_, index) => {
     transposedColumnGroups.forEach((transposedColumnGroup) => {
       args.columns.push(transposedColumnGroup[index]);
     });