[Lens] Hide some suggestions in preparation for pie charts

x-pack/plugins/lens/public/datatable_visualization/visualization.tsx

@@ -122,8 +122,8 @@ export const datatableVisualization: Visualization<
           ],
         },
         previewIcon: chartTableSVG,
-        // dont show suggestions for reduced versions or single-line tables
-        hide: table.changeType === 'reduced' || !table.isMultiRow,
+        // tables are hidden from suggestion bar, but used for drag & drop and chart switching
+        hide: true,
       },
     ];
   },

x-pack/plugins/lens/public/indexpattern_datasource/indexpattern_suggestions.test.tsx

@@ -1549,6 +1549,62 @@ describe('IndexPattern Data Source suggestions', () => {
       expect(suggestions[0].table.columns.length).toBe(1);
       expect(suggestions[0].table.columns[0].operation.label).toBe('Sum of field1');
     });
+
+    it('contains a reordering suggestion when there are exactly 2 buckets', () => {
+      const initialState = testInitialState();
+      const state: IndexPatternPrivateState = {
+        indexPatternRefs: [],
+        existingFields: {},
+        currentIndexPatternId: '1',
+        indexPatterns: expectedIndexPatterns,
+        showEmptyFields: true,
+        layers: {
+          first: {
+            ...initialState.layers.first,
+            columns: {
+              id1: {
+                label: 'Date histogram',
+                dataType: 'date',
+                isBucketed: true,
+
+                operationType: 'date_histogram',
+                sourceField: 'field2',
+                params: {
+                  interval: 'd',
+                },
+              },
+              id2: {
+                label: 'Top 5',
+                dataType: 'string',
+                isBucketed: true,
+
+                operationType: 'terms',
+                sourceField: 'field1',
+                params: { size: 5, orderBy: { type: 'alphabetical' }, orderDirection: 'asc' },
+              },
+              id3: {
+                label: 'Average of field1',
+                dataType: 'number',
+                isBucketed: false,
+
+                operationType: 'avg',
+                sourceField: 'field1',
+              },
+            },
+            columnOrder: ['id1', 'id2', 'id3'],
+          },
+        },
+      };
+
+      const suggestions = getDatasourceSuggestionsFromCurrentState(state);
+      expect(suggestions).toContainEqual(
+        expect.objectContaining({
+          table: expect.objectContaining({
+            changeType: 'reorder',
+          }),
+        })
+      );
+    });
   });
 });
 

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

@@ -478,7 +478,7 @@ function createChangedNestingSuggestion(state: IndexPatternPrivateState, layerId
     layerId,
     updatedLayer,
     label: getNestedTitle([layer.columns[secondBucket], layer.columns[firstBucket]]),
-    changeType: 'extended',
+    changeType: 'reorder',
   });
 }
 

x-pack/plugins/lens/public/types.ts

@@ -103,9 +103,16 @@ export interface TableSuggestion {
  * * `unchanged` means the table is the same in the currently active configuration
  * * `reduced` means the table is a reduced version of the currently active table (some columns dropped, but not all of them)
  * * `extended` means the table is an extended version of the currently active table (added one or multiple additional columns)
+ * * `reorder` means the table columns have changed order, which change the data as well
  * * `layers` means the change is a change to the layer structure, not to the table
  */
-export type TableChangeType = 'initial' | 'unchanged' | 'reduced' | 'extended' | 'layers';
+export type TableChangeType =
+  | 'initial'
+  | 'unchanged'
+  | 'reduced'
+  | 'extended'
+  | 'reorder'
+  | 'layers';
 
 export interface DatasourceSuggestion<T = unknown> {
   state: T;

x-pack/plugins/lens/public/xy_visualization/xy_suggestions.test.ts

@@ -186,7 +186,7 @@ describe('xy_suggestions', () => {
         isMultiRow: true,
         columns: [numCol('price'), numCol('quantity'), dateCol('date'), strCol('product')],
         layerId: 'first',
-        changeType: 'unchanged',
+        changeType: 'extended',
         label: 'Datasource title',
       },
       keptLayerIds: [],
@@ -196,6 +196,34 @@ describe('xy_suggestions', () => {
     expect(suggestion.title).toEqual('Datasource title');
   });
 
+  test('suggests only stacked bar chart when xy chart is inactive', () => {
+    const [suggestion, ...rest] = getSuggestions({
+      table: {
+        isMultiRow: true,
+        columns: [dateCol('date'), numCol('price')],
+        layerId: 'first',
+        changeType: 'unchanged',
+        label: 'Datasource title',
+      },
+      keptLayerIds: [],
+    });
+
+    expect(rest).toHaveLength(0);
+    expect(suggestion.title).toEqual('Bar chart');
+    expect(suggestion.state).toEqual(
+      expect.objectContaining({
+        layers: [
+          expect.objectContaining({
+            seriesType: 'bar_stacked',
+            xAccessor: 'date',
+            accessors: ['price'],
+            splitAccessor: undefined,
+          }),
+        ],
+      })
+    );
+  });
+
   test('hides reduced suggestions if there is a current state', () => {
     const [suggestion, ...rest] = getSuggestions({
       table: {
@@ -224,7 +252,7 @@ describe('xy_suggestions', () => {
     expect(suggestion.hide).toBeTruthy();
   });
 
-  test('does not hide reduced suggestions if xy visualization is not active', () => {
+  test('hides reduced suggestions if xy visualization is not active', () => {
     const [suggestion, ...rest] = getSuggestions({
       table: {
         isMultiRow: true,
@@ -236,7 +264,7 @@ describe('xy_suggestions', () => {
     });
 
     expect(rest).toHaveLength(0);
-    expect(suggestion.hide).toBeFalsy();
+    expect(suggestion.hide).toBeTruthy();
   });
 
   test('only makes a seriesType suggestion for unchanged table without split', () => {
@@ -419,6 +447,44 @@ describe('xy_suggestions', () => {
     });
   });
 
+  test('changes column mappings when suggestion is reorder', () => {
+    const currentState: XYState = {
+      legend: { isVisible: true, position: 'bottom' },
+      preferredSeriesType: 'bar',
+      layers: [
+        {
+          accessors: ['price'],
+          layerId: 'first',
+          seriesType: 'bar',
+          splitAccessor: 'category',
+          xAccessor: 'product',
+        },
+      ],
+    };
+    const [suggestion, ...rest] = getSuggestions({
+      table: {
+        isMultiRow: true,
+        columns: [strCol('category'), strCol('product'), numCol('price')],
+        layerId: 'first',
+        changeType: 'reorder',
+      },
+      state: currentState,
+      keptLayerIds: [],
+    });
+
+    expect(rest).toHaveLength(0);
+    expect(suggestion.state).toEqual({
+      ...currentState,
+      layers: [
+        {
+          ...currentState.layers[0],
+          xAccessor: 'category',
+          splitAccessor: 'product',
+        },
+      ],
+    });
+  });
+
   test('overwrites column to dimension mappings if a date dimension is added', () => {
     (generateId as jest.Mock).mockReturnValueOnce('dummyCol');
     const currentState: XYState = {

x-pack/plugins/lens/public/xy_visualization/xy_suggestions.ts

@@ -99,11 +99,14 @@ function getBucketMappings(table: TableSuggestion, currentState?: State) {
   // reverse the buckets before prioritization to always use the most inner
   // bucket of the highest-prioritized group as x value (don't use nested
   // buckets as split series)
-  const prioritizedBuckets = prioritizeColumns(buckets.reverse());
+  const prioritizedBuckets = prioritizeColumns([...buckets].reverse());
 
   if (!currentLayer || table.changeType === 'initial') {
     return prioritizedBuckets;
   }
+  if (table.changeType === 'reorder') {
+    return buckets;
+  }
 
   // if existing table is just modified, try to map buckets to the current dimensions
   const currentXColumnIndex = prioritizedBuckets.findIndex(
@@ -175,12 +178,24 @@ function getSuggestionsForLayer({
     keptLayerIds,
   };
 
-  const isSameState = currentState && changeType === 'unchanged';
+  // handles the simplest cases, acting as a chart switcher
+  if (!currentState && changeType === 'unchanged') {
+    return [
+      {
+        ...buildSuggestion(options),
+        title: i18n.translate('xpack.lens.xySuggestions.barChartTitle', {
+          defaultMessage: 'Bar chart',
+        }),
+      },
+    ];
+  }
 
+  const isSameState = currentState && changeType === 'unchanged';
   if (!isSameState) {
     return buildSuggestion(options);
   }
 
+  // Suggestions are either changing the data, or changing the way the data is used
   const sameStateSuggestions: Array<VisualizationSuggestion<State>> = [];
 
   // if current state is using the same data, suggest same chart with different presentational configuration
@@ -374,8 +389,11 @@ function buildSuggestion({
   return {
     title,
     score: getScore(yValues, splitBy, changeType),
-    // don't advertise chart of same type but with less data
-    hide: currentState && changeType === 'reduced',
+    hide:
+      // Only advertise very clear changes when XY chart is not active
+      (!currentState && changeType !== 'unchanged' && changeType !== 'extended') ||
+      // Don't advertise removing dimensions
+      (currentState && changeType === 'reduced'),
     state,
     previewIcon: getIconForSeries(seriesType),
   };