Activate Strict Null Checks

Set strictNullChecks to true
Make geometry and property nullable
Add tests

types/geojson/geojson-tests.ts

@@ -248,3 +248,77 @@ const typedPropertiesFeatureCollection: FeatureCollection<Point> = {
     type: "FeatureCollection",
     features: [typedPropertiesFeature]
 };
+
+// Strict Null Checks
+
+let isNull: null;
+let isPoint: Point;
+let isPointOrNull: Point | null;
+let isProperty: TestProperty;
+let isPropertyOrNull: TestProperty | null;
+
+const featureAllNull: Feature<null, null> = {
+    type: "Feature",
+    properties: null,
+    geometry: null
+};
+
+const featurePropertyNull: Feature<Point, null> = {
+    type: "Feature",
+    properties: null,
+    geometry: point
+};
+
+const featureGeometryNull: Feature<null, TestProperty> = {
+    type: "Feature",
+    properties: testProps,
+    geometry: null
+};
+
+const featureNoNull: Feature<Point, TestProperty> = {
+    type: "Feature",
+    properties: testProps,
+    geometry: point
+};
+
+const collectionAllNull: FeatureCollection<null, null> = {
+    type: "FeatureCollection",
+    features: [featureAllNull],
+};
+
+const collectionMaybeNull: FeatureCollection<Point | null, TestProperty | null> = {
+    type: "FeatureCollection",
+    features: [featureAllNull, featurePropertyNull, featureGeometryNull, featureNoNull],
+};
+
+const collectionPropertyMaybeNull: FeatureCollection<Point, TestProperty | null> = {
+    type: "FeatureCollection",
+    features: [featurePropertyNull, featureNoNull],
+};
+
+const collectionGeometryMaybeNull: FeatureCollection<Point | null, TestProperty> = {
+    type: "FeatureCollection",
+    features: [featureGeometryNull, featureNoNull],
+};
+
+const collectionNoNull: FeatureCollection<Point, TestProperty> = {
+    type: "FeatureCollection",
+    features: [featureNoNull],
+};
+
+isNull = featureAllNull.geometry;
+isPoint = featurePropertyNull.geometry;
+isNull = featureAllNull.properties;
+isProperty = featureGeometryNull.properties;
+
+isNull = collectionAllNull.features[0].geometry;
+isPointOrNull = collectionMaybeNull.features[0].geometry;
+isPoint = collectionPropertyMaybeNull.features[0].geometry;
+isPointOrNull = collectionGeometryMaybeNull.features[0].geometry;
+isPoint = collectionNoNull.features[0].geometry;
+
+isNull = collectionAllNull.features[0].properties;
+isPropertyOrNull = collectionMaybeNull.features[0].properties;
+isPropertyOrNull = collectionPropertyMaybeNull.features[0].properties;
+isProperty = collectionGeometryMaybeNull.features[0].properties;
+isProperty = collectionNoNull.features[0].properties;

types/geojson/index.d.ts

@@ -139,12 +139,12 @@ export type GeoJsonProperties = { [name: string]: any; } | null;
  * A feature object which contains a geometry and associated properties.
  * https://tools.ietf.org/html/rfc7946#section-3.2
  */
-export interface Feature<G extends GeometryObject, P = GeoJsonProperties> extends GeoJsonObject {
+export interface Feature<G extends GeometryObject | null, P = GeoJsonProperties> extends GeoJsonObject {
     type: "Feature";
     /**
      * The feature's geometry
      */
-    geometry: G | null;
+    geometry: G;
     /**
      * A value that uniquely identifies this feature in a
      * https://tools.ietf.org/html/rfc7946#section-3.2.
@@ -153,14 +153,14 @@ export interface Feature<G extends GeometryObject, P = GeoJsonProperties> extend
     /**
      * Properties associated with this feature.
      */
-    properties: P | null;
+    properties: P;
 }
 
 /**
  * A collection of feature objects.
  *  https://tools.ietf.org/html/rfc7946#section-3.3
  */
-export interface FeatureCollection<G extends GeometryObject, P = GeoJsonProperties> extends GeoJsonObject {
+export interface FeatureCollection<G extends GeometryObject | null, P = GeoJsonProperties | null> extends GeoJsonObject {
     type: "FeatureCollection";
     features: Array<Feature<G, P>>;
 }

types/geojson/tsconfig.json

@@ -6,7 +6,7 @@
         ],
         "noImplicitAny": true,
         "noImplicitThis": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "strictFunctionTypes": true,
         "baseUrl": "../",
         "typeRoots": [