Fix: Add null guards and explicit return types

- Add null/undefined check in isQueryCustomType
- Add explicit return types for resource methods
- Add null guard in EDM parser converters

Author: diegomvh

projects/angular-odata/src/lib/resources/query/builder.ts

@@ -106,7 +106,7 @@ export const binary = (value: string): QueryCustomType => ({
   value,
 });
 export const isQueryCustomType = (value: any) =>
-  typeof value === 'object' && 'type' in value && value.type in QueryCustomTypes;
+  value !== null && value !== undefined && typeof value === 'object' && 'type' in value && value.type in QueryCustomTypes;
 
 export const isRawType = (value: any) =>
   isQueryCustomType(value) && (value as QueryCustomType).type === QueryCustomTypes.Raw;

projects/angular-odata/src/lib/resources/types/entity.ts

@@ -58,19 +58,19 @@ export class ODataEntityResource<T> extends ODataResource<T> {
     });
   }
 
-  navigationProperty<N>(path: string) {
+  navigationProperty<N>(path: string): ODataNavigationPropertyResource<N> {
     return ODataNavigationPropertyResource.fromResource<N>(this, path);
   }
 
-  property<P>(path: string) {
+  property<P>(path: string): ODataPropertyResource<P> {
     return ODataPropertyResource.fromResource<P>(this, path);
   }
 
-  action<P, R>(path: string) {
+  action<P, R>(path: string): ODataActionResource<P, R> {
     return ODataActionResource.fromResource<P, R>(this, path);
   }
 
-  function<P, R>(path: string) {
+  function<P, R>(path: string): ODataFunctionResource<P, R> {
     return ODataFunctionResource.fromResource<P, R>(this, path);
   }
 

projects/angular-odata/src/lib/resources/types/navigation-property.ts

@@ -122,11 +122,11 @@ export class ODataNavigationPropertyResource<T> extends ODataResource<T> {
     });
   }
 
-  navigationProperty<N>(path: string) {
+  navigationProperty<N>(path: string): ODataNavigationPropertyResource<N> {
     return ODataNavigationPropertyResource.fromResource<N>(this, path);
   }
 
-  property<P>(path: string) {
+  property<P>(path: string): ODataPropertyResource<P> {
     return ODataPropertyResource.fromResource<P>(this, path);
   }
 

projects/angular-odata/src/lib/resources/types/singleton.ts

@@ -54,19 +54,19 @@ export class ODataSingletonResource<T> extends ODataResource<T> {
     return singleton;
   }
 
-  navigationProperty<N>(path: string) {
+  navigationProperty<N>(path: string): ODataNavigationPropertyResource<N> {
     return ODataNavigationPropertyResource.fromResource<N>(this, path);
   }
 
-  property<P>(path: string) {
+  property<P>(path: string): ODataPropertyResource<P> {
     return ODataPropertyResource.fromResource<P>(this, path);
   }
 
-  action<P, R>(path: string) {
+  action<P, R>(path: string): ODataActionResource<P, R> {
     return ODataActionResource.fromResource<P, R>(this, path);
   }
 
-  function<P, R>(path: string) {
+  function<P, R>(path: string): ODataFunctionResource<P, R> {
     return ODataFunctionResource.fromResource<P, R>(this, path);
   }
 

projects/angular-odata/src/lib/schema/parsers/edm.ts

@@ -25,10 +25,10 @@ const EdmParser = <T>(
 });
 
 const Identity = (v: any) => v;
-const toNumber = (v: any) => Number(v);
-const toString = (v: any) => v.toString();
-const toBoolean = (v: any) => Boolean(v);
-const toDate = (v: any) => new Date(v);
+const toNumber = (v: any) => v && Number(v);
+const toString = (v: any) => v && v.toString();
+const toBoolean = (v: any) => v && Boolean(v);
+const toDate = (v: any) => v && new Date(v);
 
 export const EDM_PARSERS: { [type: string]: FieldParser<any> } = {
   //Edm.Guid 16-byte (128-bit) unique identifier