(core) Use individual choices for filtering choice lists

Test Plan: Wrote unit and browser tests that verify new behavior.

Reviewers: paulfitz, dsagal

Reviewed By: dsagal

Subscribers: alexmojaki

Differential Revision: https://phab.getgrist.com/D2855

app/common/ColumnFilterFunc.ts

@@ -1,18 +1,29 @@
 import { CellValue } from "app/common/DocActions";
 import { FilterState, makeFilterState } from "app/common/FilterState";
+import { decodeObject } from "app/plugin/objtypes";
+import { isList } from "./gristTypes";
 
 export type ColumnFilterFunc = (value: CellValue) => boolean;
 
 // Returns a filter function for a particular column: the function takes a cell value and returns
 // whether it's accepted according to the given FilterState.
-export function makeFilterFunc({ include, values }: FilterState): ColumnFilterFunc {
+export function makeFilterFunc({ include, values }: FilterState,
+                               columnType?: string): ColumnFilterFunc {
   // NOTE: This logic results in complex values and their stringified JSON representations as equivalent.
   // For example, a TypeError in the formula column and the string '["E","TypeError"]' would be seen as the same.
   // TODO: This narrow corner case seems acceptable for now, but may be worth revisiting.
-  return (val: CellValue) => (values.has(Array.isArray(val) ? JSON.stringify(val) : val) === include);
+  return (val: CellValue) => {
+    if (isList(val) && columnType === 'ChoiceList') {
+      const list = decodeObject(val) as unknown[];
+      return list.some(item => values.has(item as any) === include);
+    }
+
+    return (values.has(Array.isArray(val) ? JSON.stringify(val) : val) === include);
+  };
 }
 
 // Given a JSON string, returns a ColumnFilterFunc
-export function buildColFilter(filterJson: string | undefined): ColumnFilterFunc | null {
-  return filterJson ? makeFilterFunc(makeFilterState(filterJson)) : null;
+export function buildColFilter(filterJson: string | undefined,
+                               columnType?: string): ColumnFilterFunc | null {
+  return filterJson ? makeFilterFunc(makeFilterState(filterJson), columnType) : null;
 }

app/common/gristTypes.ts

@@ -136,12 +136,19 @@ export function isCensored(value: CellValue): value is [GristObjCode.Censored] {
   return getObjCode(value) === GristObjCode.Censored;
 }
 
+/**
+ * Returns whether a value (as received in a DocAction) represents a list.
+ */
+ export function isList(value: CellValue): value is [GristObjCode.List, ...unknown[]] {
+  return Array.isArray(value) && value[0] === GristObjCode.List;
+}
+
 /**
  * Returns whether a value (as received in a DocAction) represents a list or is null,
  * which is a valid value for list types in grist.
  */
 export function isListOrNull(value: CellValue): boolean {
-  return value === null || (Array.isArray(value) && value[0] === GristObjCode.List);
+  return value === null || isList(value);
 }
 
 /**