Improve exception handling, enum numeric value

Author: ddidgdimitrov-infragistics

QueryExecutor.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
 using System.Globalization;
 using System.Linq.Expressions;
 using System.Reflection;
@@ -34,13 +34,15 @@ public static object[] Run<TSource, TTarget>(this IQueryable<TSource> source, Qu
             return db is not null ? BuildQuery<TSource, TTarget>(db, source, query, mapper).ToArray() : Array.Empty<object>();
         }
 
-        public static MethodInfo? GetGenericMethod(Type executorType, int attributeCount, Type[] genericArgs)
+        public static MethodInfo? GetRunMethod(Type executorType, Type[] genericArgs)
         {
-            var method = executorType
+            return executorType
                 .GetMethods(BindingFlags.Static | BindingFlags.Public)
-                .FirstOrDefault(m => m.CustomAttributes.Count() == attributeCount);
-
-            return method?.MakeGenericMethod(genericArgs);
+                .FirstOrDefault(m =>
+                    m.Name == "Run" &&
+                    m.IsGenericMethodDefinition &&
+                    m.GetGenericArguments().Length == genericArgs.Length)
+                ?.MakeGenericMethod(genericArgs);
         }
 
         private static IQueryable<object> BuildQuery<TSource, TTarget>(DbContext db, IQueryable<TSource> source, Query? query, IMapper? mapper = null)
@@ -232,23 +234,19 @@ private static Expression BuildInExpression<T>(DbContext db, Query? query, Membe
 
         private static IEnumerable<dynamic> RunSubquery(DbContext db, Query? query)
         {
-            var t = query?.Entity.ToLower(CultureInfo.InvariantCulture) ?? string.Empty;
-            var p = db.GetType().GetProperty(t, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance) ?? throw new InvalidOperationException($"Property '{t}' not found on type '{db.GetType()}'");
+            var propName = query?.Entity.ToLower(CultureInfo.InvariantCulture) ?? string.Empty;
+            var prop = db.GetType().GetProperty(propName, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance)
+                ?? throw new InvalidOperationException($"Property '{propName}' not found on type '{db.GetType()}'");
 
             var methods = typeof(QueryExecutor).GetMethods(BindingFlags.Static | BindingFlags.Public);
             var method = methods?.FirstOrDefault(m => m.CustomAttributes.Count() == 1);
-            var dbSet = p.GetValue(db);
-            var genericType = p.PropertyType.GetGenericArguments().FirstOrDefault();
-
-            if (dbSet != null && genericType != null)
-            {
+            var dbSet = prop.GetValue(db) ?? throw new ValidationException($"DbSet property '{prop.Name}' is null in DbContext.");
+            var genericType = prop.PropertyType.GetGenericArguments().FirstOrDefault() ?? throw new ValidationException($"Missing DbSet generic type");
 
-                var genericMethod = GetGenericMethod(typeof(QueryExecutor), 1, [genericType]);
+            var genericMethod = GetRunMethod(typeof(QueryExecutor), [genericType]);
 
-                var queryable = dbSet?.GetType().GetMethod("AsQueryable")?.Invoke(dbSet, null);
-                return genericMethod?.Invoke(null, [queryable, query]) as IEnumerable<dynamic> ?? Array.Empty<dynamic>();
-            }
-            return Enumerable.Empty<dynamic>();
+            var queryable = dbSet?.GetType().GetMethod("AsQueryable")?.Invoke(dbSet, null);
+            return genericMethod?.Invoke(null, [queryable, query]) as IEnumerable<dynamic> ?? Array.Empty<dynamic>();
         }
 
         private static dynamic? ProjectField(object? obj, string field)
@@ -269,10 +267,21 @@ private static Expression GetSearchValue(JsonValue? jsonVal, Type targetType)
 
             if (nonNullableType.IsEnum)
             {
-                var enumValue = jsonVal.Deserialize<string>();
-                if (enumValue != null)
+                if (valueKind == JsonValueKind.String)
+                {
+                    var enumValue = jsonVal.Deserialize<string>();
+                    if (enumValue != null)
+                    {
+                        return Expression.Constant(Enum.Parse(nonNullableType, enumValue));
+                    }
+                }
+                else if (valueKind == JsonValueKind.Number)
                 {
-                    return Expression.Constant(Enum.Parse(nonNullableType, enumValue));
+                    var enumValue = jsonVal.Deserialize<int?>();
+                    if (enumValue != null)
+                    {
+                        return Expression.Constant(Enum.ToObject(nonNullableType, enumValue));
+                    }
                 }
             }
 

Services/QueryBuilderService.cs

@@ -1,8 +1,9 @@
-using AutoMapper;
-using Microsoft.EntityFrameworkCore;
-using Microsoft.Extensions.Logging;
+using System.ComponentModel.DataAnnotations;
 using System.Globalization;
 using System.Reflection;
+using AutoMapper;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
 
 namespace Infragistics.QueryBuilder.Executor
 {
@@ -15,23 +16,27 @@ public Dictionary<string, object[]> RunQuery(Query query)
             var t = query.Entity.ToLower(CultureInfo.InvariantCulture);
 
             var propInfo = db?.GetType().GetProperties()
-                .FirstOrDefault(p => p.PropertyType.IsGenericType && p.Name.ToLower(CultureInfo.InvariantCulture) == t && p.PropertyType.GetGenericTypeDefinition() == typeof(DbSet<>));
-            if (propInfo != null)
+                .FirstOrDefault(p =>
+                    p.PropertyType.IsGenericType &&
+                    p.Name.ToLower(CultureInfo.InvariantCulture) == t &&
+                    p.PropertyType.GetGenericTypeDefinition() == typeof(DbSet<>))
+                ?? throw new InvalidOperationException($"Unknown entity {t}");
+
+            var dbSet = propInfo.GetValue(db) ?? throw new ValidationException($"DbSet property '{propInfo.Name}' is null in DbContext.");
+            var dbGenericType = dbSet.GetType().GenericTypeArguments.FirstOrDefault() ?? throw new ValidationException($"Missing DbSet generic type");
+
+            var resultProperty = typeof(TResults).GetProperty(t, BindingFlags.Instance | BindingFlags.Public | BindingFlags.IgnoreCase)
+                ?? throw new ValidationException($"Unknown entity {t}");
+
+            var dtoGenericType = resultProperty.PropertyType.GetElementType() ?? throw new ValidationException($"Missing Dto generic type");
+
+            var genericMethod = QueryExecutor.GetRunMethod(typeof(QueryExecutor), [dbGenericType, dtoGenericType]);
+
+            var queryable = dbSet.GetType().GetMethod("AsQueryable")?.Invoke(dbSet, null)
+                ?? throw new InvalidOperationException($"DbSet '{propInfo.Name}' does not support AsQueryable().");
+            if ( genericMethod?.Invoke(null, [queryable, query, mapper]) is object[] propRes)
             {
-                var dbSet = propInfo.GetValue(db);
-                var dbGenericType = dbSet?.GetType()?.GenericTypeArguments.FirstOrDefault();
-                var dtoGenericType = typeof(TResults).GetProperty(propInfo.Name)?.PropertyType.GetElementType();
-
-                if (dbSet != null && dbGenericType != null && dtoGenericType != null)
-                {
-                    var genericMethod = QueryExecutor.GetGenericMethod(typeof(QueryExecutor), 2, [dbGenericType, dtoGenericType]);
-
-                    var queryable = dbSet.GetType().GetMethod("AsQueryable")?.Invoke(dbSet, null);
-                    if (queryable != null && genericMethod?.Invoke(null, [queryable, query, mapper]) is object[] propRes)
-                    {
-                        return new Dictionary<string, object[]> { { propInfo.Name.ToLowerInvariant(), propRes } };
-                    }
-                }
+                return new Dictionary<string, object[]> { { propInfo.Name.ToLowerInvariant(), propRes } };
             }
 
             throw new InvalidOperationException($"Unknown entity {t}");