Fix passing reference to global-state object when creating filter (#1279)

* pass reference to `global-state` object when creating feature filter

* Add global-state parameter to featureFilter function

---------

Co-authored-by: Harel M <[email protected]>

Author: melitele

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## main
 
 ### ✨ Features and improvements
+- Added `global-state` parameter to `featureFilter` function ([#1279](https://github.com/maplibre/maplibre-style-spec/pull/1279))
 - _...Add new stuff here..._
 
 ### 🐞 Bug fixes

src/feature_filter/feature_filter.test.ts

@@ -97,6 +97,12 @@ describe('filter', () => {
         expect(withinFilter.filter({zoom: 3}, featureInTile, canonical)).toBe(false);
     });
 
+    test('expression, global-state', () => {
+        const {filter} = featureFilter(['==', ['global-state', 'x'], ['get', 'x']], {x: 1});
+        expect(filter(undefined, {properties: {x: 1}} as any as Feature)).toBe(true);
+        expect(filter(undefined, {properties: {x: 2}} as any as Feature)).toBe(false);
+    });
+
     legacyFilterTests(featureFilter);
 
 });

src/feature_filter/index.ts

@@ -2,7 +2,7 @@ import {createExpression, findGlobalStateRefs} from '../expression';
 import type {GlobalProperties, Feature} from '../expression';
 import {ICanonicalTileID} from '../tiles_and_coordinates';
 import {StylePropertySpecification} from '..';
-import {ExpressionFilterSpecification} from '../types.g';
+import {ExpressionFilterSpecification, type FilterSpecification} from '../types.g';
 
 type FilterExpression = (
     globalProperties: GlobalProperties,
@@ -75,19 +75,20 @@ const filterSpec = {
  * passes its test.
  *
  * @private
- * @param {Array} filter MapLibre filter
- * @returns {Function} filter-evaluating function
+ * @param filter MapLibre filter
+ * @param [globalState] Global state object to be used for evaluating 'global-state' expressions
+ * @returns filter-evaluating function
  */
-export function featureFilter(filter: any): FeatureFilter {
+export function featureFilter(filter: FilterSpecification | void, globalState?: Record<string, any>): FeatureFilter {
     if (filter === null || filter === undefined) {
         return {filter: () => true, needGeometry: false, getGlobalStateRefs: () => new Set()};
     }
 
     if (!isExpressionFilter(filter)) {
-        filter = convertFilter(filter);
+        filter = convertFilter(filter) as ExpressionFilterSpecification;
     }
 
-    const compiled = createExpression(filter, filterSpec as StylePropertySpecification);
+    const compiled = createExpression(filter, filterSpec as StylePropertySpecification, globalState);
     if (compiled.result === 'error') {
         throw new Error(compiled.value.map(err => `${err.key}: ${err.message}`).join(', '));
     } else {
@@ -114,7 +115,7 @@ function geometryNeeded(filter) {
     return false;
 }
 
-function convertFilter(filter?: Array<any> | null): unknown {
+function convertFilter(filter?: Array<any> | null | void): unknown {
     if (!filter) return true;
     const op = filter[0];
     if (filter.length <= 1) return (op !== 'any');