From 7c9e2692fc5d600cdfef5d5fd06b5b242a24bec0 Mon Sep 17 00:00:00 2001
From: Arthur Vickers <ajcvickers@hotmail.com>
Date: Thu, 25 Jan 2024 20:05:33 +0000
Subject: [PATCH] Support empty strings in primitive collection columns

Fixes #32896
---
 src/EFCore/Properties/CoreStrings.Designer.cs |  6 ++
 src/EFCore/Properties/CoreStrings.resx        | 57 ++++++++++---------
 .../Storage/Json/JsonValueReaderWriter.cs     |  5 ++
 .../PrimitiveCollectionsQuerySqliteTest.cs    | 42 ++++++++++++++
 4 files changed, 83 insertions(+), 27 deletions(-)

diff --git a/src/EFCore/Properties/CoreStrings.Designer.cs b/src/EFCore/Properties/CoreStrings.Designer.cs
index 68556ca9280..1eb205020bb 100644
--- a/src/EFCore/Properties/CoreStrings.Designer.cs
+++ b/src/EFCore/Properties/CoreStrings.Designer.cs
@@ -999,6 +999,12 @@ public static string EmptyComplexType(object? complexType)
                 GetString("EmptyComplexType", nameof(complexType)),
                 complexType);
 
+        /// <summary>
+        ///     The empty string is not valid JSON.
+        /// </summary>
+        public static string EmptyJsonString
+            => GetString("EmptyJsonString");
+
         /// <summary>
         ///     Cannot translate '{comparisonOperator}' on a subquery expression of entity type '{entityType}' because it has a composite primary key. See https://go.microsoft.com/fwlink/?linkid=2141942 for information on how to rewrite your query.
         /// </summary>
diff --git a/src/EFCore/Properties/CoreStrings.resx b/src/EFCore/Properties/CoreStrings.resx
index c2a088acf13..9d7fe91b5f7 100644
--- a/src/EFCore/Properties/CoreStrings.resx
+++ b/src/EFCore/Properties/CoreStrings.resx
@@ -1,17 +1,17 @@
 <?xml version="1.0" encoding="utf-8"?>
 <root>
-  <!-- 
-    Microsoft ResX Schema 
-    
+  <!--
+    Microsoft ResX Schema
+
     Version 2.0
-    
-    The primary goals of this format is to allow a simple XML format 
-    that is mostly human readable. The generation and parsing of the 
-    various data types are done through the TypeConverter classes 
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
     associated with the data types.
-    
+
     Example:
-    
+
     ... ado.net/XML headers & schema ...
     <resheader name="resmimetype">text/microsoft-resx</resheader>
     <resheader name="version">2.0</resheader>
@@ -26,36 +26,36 @@
         <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
         <comment>This is a comment</comment>
     </data>
-                
-    There are any number of "resheader" rows that contain simple 
+
+    There are any number of "resheader" rows that contain simple
     name/value pairs.
-    
-    Each data row contains a name, and value. The row also contains a 
-    type or mimetype. Type corresponds to a .NET class that support 
-    text/value conversion through the TypeConverter architecture. 
-    Classes that don't support this are serialized and stored with the 
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
     mimetype set.
-    
-    The mimetype is used for serialized objects, and tells the 
-    ResXResourceReader how to depersist the object. This is currently not 
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
     extensible. For a given mimetype the value must be set accordingly:
-    
-    Note - application/x-microsoft.net.object.binary.base64 is the format 
-    that the ResXResourceWriter will generate, however the reader can 
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
     read any of the formats listed below.
-    
+
     mimetype: application/x-microsoft.net.object.binary.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
             : and then encoded with base64 encoding.
-    
+
     mimetype: application/x-microsoft.net.object.soap.base64
-    value   : The object must be serialized with 
+    value   : The object must be serialized with
             : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
             : and then encoded with base64 encoding.
 
     mimetype: application/x-microsoft.net.object.bytearray.base64
-    value   : The object must be serialized into a byte array 
+    value   : The object must be serialized into a byte array
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
@@ -489,6 +489,9 @@
   <data name="EmptyComplexType" xml:space="preserve">
     <value>Complex type '{complexType}' has no properties defines. Configure at least one property or don't include this type in the model.</value>
   </data>
+  <data name="EmptyJsonString" xml:space="preserve">
+    <value>The empty string is not valid JSON.</value>
+  </data>
   <data name="EntityEqualityOnCompositeKeyEntitySubqueryNotSupported" xml:space="preserve">
     <value>Cannot translate '{comparisonOperator}' on a subquery expression of entity type '{entityType}' because it has a composite primary key. See https://go.microsoft.com/fwlink/?linkid=2141942 for information on how to rewrite your query.</value>
   </data>
diff --git a/src/EFCore/Storage/Json/JsonValueReaderWriter.cs b/src/EFCore/Storage/Json/JsonValueReaderWriter.cs
index 6d08502f54b..0536aa6ae43 100644
--- a/src/EFCore/Storage/Json/JsonValueReaderWriter.cs
+++ b/src/EFCore/Storage/Json/JsonValueReaderWriter.cs
@@ -63,6 +63,11 @@ internal JsonValueReaderWriter()
     /// <returns>The read value.</returns>
     public object FromJsonString(string json, object? existingObject = null)
     {
+        if (string.IsNullOrWhiteSpace(json))
+        {
+            throw new InvalidOperationException(CoreStrings.EmptyJsonString);
+        }
+
         var readerManager = new Utf8JsonReaderManager(new JsonReaderData(Encoding.UTF8.GetBytes(json)), null);
         readerManager.MoveNext();
         return FromJson(ref readerManager, existingObject);
diff --git a/test/EFCore.Sqlite.FunctionalTests/Query/PrimitiveCollectionsQuerySqliteTest.cs b/test/EFCore.Sqlite.FunctionalTests/Query/PrimitiveCollectionsQuerySqliteTest.cs
index 372f1e4ab3a..415eb4cd030 100644
--- a/test/EFCore.Sqlite.FunctionalTests/Query/PrimitiveCollectionsQuerySqliteTest.cs
+++ b/test/EFCore.Sqlite.FunctionalTests/Query/PrimitiveCollectionsQuerySqliteTest.cs
@@ -1385,6 +1385,48 @@ FROM json_each(@__strings_0) AS "s"
     """);
     }
 
+    [ConditionalTheory]
+    [InlineData(false)]
+    [InlineData(true)] // Issue #32896
+    public async Task Empty_string_used_for_primitive_collection_throws(bool async)
+    {
+        await using var connection = new SqliteConnection("DataSource=:memory:");
+        await connection.OpenAsync();
+
+        await using var context = new SimpleContext(connection);
+        await context.Database.EnsureDeletedAsync();
+        await context.Database.EnsureCreatedAsync();
+
+        await context.Database.ExecuteSqlRawAsync("INSERT INTO SimpleEntities (List) VALUES ('');");
+
+        var set = context.SimpleEntities;
+
+        var message = await Assert.ThrowsAsync<InvalidOperationException>(
+            async () =>
+            {
+                if (async)
+                {
+                    await set.FirstAsync();
+                }
+                else
+                {
+                    set.First();
+                }
+            });
+
+        Assert.Equal(CoreStrings.EmptyJsonString, message.Message);
+    }
+
+    public class SimpleContext(SqliteConnection connection) : DbContext
+    {
+        public DbSet<SimpleEntity> SimpleEntities => Set<SimpleEntity>();
+
+        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+            => optionsBuilder.UseSqlite(connection);
+    }
+
+    public record SimpleEntity(int Id, IEnumerable<string> List);
+
     [ConditionalFact]
     public virtual void Check_all_tests_overridden()
         => TestHelpers.AssertAllMethodsOverridden(GetType());