fix time scaling bugs (#86444)

Author: flash1293

x-pack/plugins/lens/public/indexpattern_datasource/indexpattern.test.ts

@@ -530,6 +530,9 @@ describe('IndexPattern Data Source', () => {
           "outputColumnId": Array [
             "col1",
           ],
+          "outputColumnName": Array [
+            "Count of records",
+          ],
           "targetUnit": Array [
             "h",
           ],

x-pack/plugins/lens/public/indexpattern_datasource/suffix_formatter.test.ts

@@ -25,4 +25,20 @@ describe('suffix formatter', () => {
     expect(convertMock).toHaveBeenCalledWith(12345);
     expect(formatFactory).toHaveBeenCalledWith({ id: 'nestedFormatter', params: nestedParams });
   });
+
+  it('should not add suffix to empty strings', () => {
+    const convertMock = jest.fn((x) => '');
+    const formatFactory = jest.fn(() => ({ convert: convertMock }));
+    const SuffixFormatter = getSuffixFormatter((formatFactory as unknown) as FormatFactory);
+    const nestedParams = { abc: 123 };
+    const formatterInstance = new SuffixFormatter({
+      unit: 'h',
+      id: 'nestedFormatter',
+      params: nestedParams,
+    });
+
+    const result = formatterInstance.convert(12345);
+
+    expect(result).toEqual('');
+  });
 });

x-pack/plugins/lens/public/indexpattern_datasource/suffix_formatter.ts

@@ -49,6 +49,11 @@ export function getSuffixFormatter(formatFactory: FormatFactory) {
         val
       );
 
+      // do not add suffixes to empty strings
+      if (formattedValue === '') {
+        return '';
+      }
+
       if (suffix) {
         return `${formattedValue}${suffix}`;
       }

x-pack/plugins/lens/public/indexpattern_datasource/to_expression.ts

@@ -121,6 +121,7 @@ function getExpressionForLayer(
             dateColumnId: [firstDateHistogramColumn![0]],
             inputColumnId: [id],
             outputColumnId: [id],
+            outputColumnName: [col.label],
             targetUnit: [col.timeScale!],
           },
         };