fix: Replace unsafe in-operator checks with compile-time type guards

src/common/property-filter-type-guards.ts

@@ -0,0 +1,17 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: MIT-0
+import { PropertyFilterProps } from '@cloudscape-design/components/property-filter';
+
+export function isTokenGroup(
+  tokenOrGroup: PropertyFilterProps.Token | PropertyFilterProps.TokenGroup,
+): tokenOrGroup is PropertyFilterProps.TokenGroup {
+  const key: keyof PropertyFilterProps.TokenGroup = 'operation';
+  return key in tokenOrGroup;
+}
+
+export function isToken(
+  tokenOrGroup: PropertyFilterProps.Token | PropertyFilterProps.TokenGroup,
+): tokenOrGroup is PropertyFilterProps.Token {
+  const key: keyof PropertyFilterProps.Token = 'operator';
+  return key in tokenOrGroup;
+}

src/fake-server/distributions.ts

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: MIT-0
 import { PropertyFilterProps } from '@cloudscape-design/components/property-filter';
 
+import { isToken, isTokenGroup } from '../common/property-filter-type-guards';
 import { Distribution } from './types';
 import fetchJson from './utils/fetch-json';
 
@@ -99,14 +100,14 @@ function filterItemsByProperty(options: FetchDistributionOptions) {
       opFn: (a: boolean, b: boolean) => void,
       tokenOrGroup: Token | TokenGroup,
     ): boolean {
-      if ('operation' in tokenOrGroup) {
+      if (isTokenGroup(tokenOrGroup)) {
         const nextOpFn = operationFn<boolean>(tokenOrGroup.operation!);
         return tokenOrGroup.tokens.reduce(
           (include: boolean, token: Token | TokenGroup) => filterWithToken(include, nextOpFn, token),
           operation === 'and',
         );
       }
-      if ('operator' in tokenOrGroup) {
+      if (isToken(tokenOrGroup)) {
         const comparator = getComparatorForOperator(tokenOrGroup.operator);
         const searchableProps = tokenOrGroup.propertyKey ? [tokenOrGroup.propertyKey] : Object.keys(item);
         return searchableProps.some(propertyKey => {

src/pages/table-saved-filters/filter-set-modals.tsx

@@ -13,6 +13,7 @@ import Modal from '@cloudscape-design/components/modal';
 import { PropertyFilterProps } from '@cloudscape-design/components/property-filter';
 import SpaceBetween from '@cloudscape-design/components/space-between';
 
+import { isTokenGroup } from '../../common/property-filter-type-guards';
 import { FilterSet } from './use-filter-sets';
 
 function queryToString(
@@ -44,7 +45,7 @@ function queryToString(
   }
 
   function tokenOrGroupToString(tokenOrGroup: PropertyFilterProps.TokenGroup | PropertyFilterProps.Token): string {
-    if ('operation' in tokenOrGroup) {
+    if (isTokenGroup(tokenOrGroup)) {
       return '(' + tokenOrGroup.tokens.map(tokenOrGroupToString).join(`, ${tokenOrGroup.operation} `) + ')';
     } else {
       return tokenToString(tokenOrGroup);

test/e2e/a11y.test.ts

@@ -77,6 +77,10 @@ describe('Checking examples accessibility', function () {
 
         await browser.execute(fs.readFileSync(require.resolve('axe-core/axe.min.js'), 'utf8'));
         type AxeResult = { result: Axe.AxeResults } | { error: Error };
+        function isAxeError(response: AxeResult): response is { error: Error } {
+          const key: keyof { error: Error } = 'error';
+          return key in response;
+        }
         const runAxe = (done: (result: AxeResult) => void) =>
           axe
             .run({
@@ -92,7 +96,7 @@ describe('Checking examples accessibility', function () {
         // executeAsync has incorrect typings: https://github.com/webdriverio/webdriverio/issues/6206
         const response = (await browser.executeAsync(runAxe as any)) as AxeResult;
 
-        if ('error' in response) {
+        if (isAxeError(response)) {
           throw response.error;
         }