(core) Filter menu show all options for Bool/Choice/Choice List columns

Summary:
> Toggle, Choice, and Choice List need all possible values available in filter, not just values present in current records
https://grist.quip.com/cjw4A8AHx1vh/Filtering-Improvements#temp:C:PZHc42e8be8cd8547bb8ce93fdb0

Test Plan: Adds new nbrowser test

Reviewers: georgegevoian

Reviewed By: georgegevoian

Differential Revision: https://phab.getgrist.com/D3436

app/client/models/ColumnFilter.ts

@@ -29,6 +29,10 @@ export class ColumnFilter extends Disposable {
     this.setState(_initialFilterJson);
   }
 
+  public get columnType() {
+    return this._columnType;
+  }
+
   public setState(filterJson: string|FilterSpec) {
     const state = makeFilterState(filterJson);
     this._include = state.include;

app/client/models/ColumnFilterMenuModel.ts

@@ -22,10 +22,10 @@ export class ColumnFilterMenuModel extends Disposable {
   // computes a set of all keys that matches the search text.
   public readonly filterSet = Computed.create(this, this.searchValue, (_use, searchValue) => {
     const searchRegex = new RegExp(escapeRegExp(searchValue), 'i');
+    const showAllOptions = ['Bool', 'Choice', 'ChoiceList'].includes(this.columnFilter.columnType!);
     return new Set(
       this._valueCount
-        .filter(([_, {count}]) => count)
-        .filter(([_, {label}]) => searchRegex.test(label))
+        .filter(([_, {label, count}]) => (showAllOptions ? true : count) && searchRegex.test(label))
         .map(([key]) => key)
     );
   });

app/client/ui/ColumnFilterMenu.ts

@@ -276,6 +276,23 @@ function formatUniqueCount(values: Array<[CellValue, IFilterCount]>) {
   return count ? '(' + count.toLocaleString() + ')' : '';
 }
 
+/**
+ * Returns a new `Map` object to holds pairs of `CellValue` and `IFilterCount`. For `Bool`, `Choice`
+ * and `ChoiceList` type of column, the map is initialized with all possible values in order to make
+ * sure they get shown to the user.
+ */
+function getEmptyCountMap(fieldOrColumn: ViewFieldRec|ColumnRec): Map<CellValue, IFilterCount> {
+  const columnType = fieldOrColumn.origCol().type();
+  let values: any[] = [];
+  if (columnType === 'Bool') {
+    values = [true, false];
+  } else if (['Choice', 'ChoiceList'].includes(columnType)) {
+    const options = fieldOrColumn.origCol().widgetOptionsJson;
+    values = options.prop('choices')();
+  }
+  return new Map(values.map((v) => [v, {label: String(v), count: 0}]));
+}
+
 /**
  * Returns content for the newly created columnFilterMenu; for use with setPopupToCreateDom().
  */
@@ -297,14 +314,13 @@ export function createFilterMenu(openCtl: IOpenController, sectionFilter: Sectio
   sectionFilter.setFilterOverride(fieldOrColumn.getRowId(), columnFilter); // Will be removed on menu disposal
 
   const [allRows, hiddenRows] = partition(Array.from(rowSource.getAllRows()), filterFunc.get());
-  const valueCounts: Map<CellValue, {label: string, count: number}> = new Map();
+  const valueCounts = getEmptyCountMap(fieldOrColumn);
   addCountsToMap(valueCounts, allRows, {keyMapFunc, labelMapFunc, columnType});
   addCountsToMap(valueCounts, hiddenRows, {keyMapFunc, labelMapFunc, columnType,
                                                                areHiddenRows: true});
 
   const model = ColumnFilterMenuModel.create(openCtl, columnFilter, Array.from(valueCounts));
 
-
   return columnFilterMenu(openCtl, {
     model,
     valueCounts,