From ab6fa7de82e06e13c9498595c3ad02a4dc1d9a98 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dan=C3=ADel=20P=2E=20Purkh=C3=BAs?= <purkhusid@gmail.com>
Date: Thu, 29 Aug 2024 09:05:57 +0000
Subject: [PATCH 1/2] Allow empty strings

## What?
DynamoDB has supported empty strings for non-key attributes since mid 2020: https://aws.amazon.com/about-aws/whats-new/2020/05/amazon-dynamodb-now-supports-empty-values-for-non-key-string-and-binary-attributes-in-dynamodb-tables/
---
 src/FSharp.AWS.DynamoDB/Picklers/PrimitivePicklers.fs        | 2 --
 tests/FSharp.AWS.DynamoDB.Tests/RecordGenerationTests.fs     | 4 +---
 tests/FSharp.AWS.DynamoDB.Tests/SimpleTableOperationTests.fs | 4 ++++
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/FSharp.AWS.DynamoDB/Picklers/PrimitivePicklers.fs b/src/FSharp.AWS.DynamoDB/Picklers/PrimitivePicklers.fs
index f2e2ba5..277feb4 100644
--- a/src/FSharp.AWS.DynamoDB/Picklers/PrimitivePicklers.fs
+++ b/src/FSharp.AWS.DynamoDB/Picklers/PrimitivePicklers.fs
@@ -36,8 +36,6 @@ type StringPickler() =
     override _.Pickle s =
         if isNull s then
             AttributeValue(NULL = true)
-        elif s = "" then
-            invalidOp "empty strings not supported by DynamoDB."
         else
             AttributeValue(s)
         |> Some
diff --git a/tests/FSharp.AWS.DynamoDB.Tests/RecordGenerationTests.fs b/tests/FSharp.AWS.DynamoDB.Tests/RecordGenerationTests.fs
index 7d4c1c0..2d48b67 100644
--- a/tests/FSharp.AWS.DynamoDB.Tests/RecordGenerationTests.fs
+++ b/tests/FSharp.AWS.DynamoDB.Tests/RecordGenerationTests.fs
@@ -30,10 +30,8 @@ module ``Record Generation Tests`` =
                         test <@ r' = r @>
                 with
                 // account for random inputs not supported by the library
-                | :? InvalidOperationException as e when e.Message = "empty strings not supported by DynamoDB." -> ()
                 | :? ArgumentException as e when
-                    e.Message.Contains "unsupported key name" && e.Message.Contains "should be 1 to 64k long (as utf8)"
-                    ->
+                    e.Message.Contains "unsupported key name" && e.Message.Contains "should be 1 to 64k long (as utf8)" ->
                     ()
 
             Check.One(config, roundTrip)
diff --git a/tests/FSharp.AWS.DynamoDB.Tests/SimpleTableOperationTests.fs b/tests/FSharp.AWS.DynamoDB.Tests/SimpleTableOperationTests.fs
index 1eadef9..0e153c9 100644
--- a/tests/FSharp.AWS.DynamoDB.Tests/SimpleTableOperationTests.fs
+++ b/tests/FSharp.AWS.DynamoDB.Tests/SimpleTableOperationTests.fs
@@ -18,6 +18,8 @@ module SimpleTableTypes =
           [<RangeKey>]
           RangeKey: string
 
+          EmptyString: string
+
           Value: int64
 
           Tuple: int64 * int64
@@ -46,6 +48,7 @@ type ``Simple Table Operation Tests``(fixture: TableFixture) =
     let mkItem () =
         { HashKey = guid ()
           RangeKey = guid ()
+          EmptyString = ""
           Value = rand ()
           Tuple = rand (), rand ()
           Map = seq { for _ in 0L .. rand () % 5L -> "K" + guid (), rand () } |> Map.ofSeq
@@ -139,6 +142,7 @@ type ``TransactWriteItems tests``(fixture: TableFixture) =
     let mkItem () =
         { HashKey = guid ()
           RangeKey = guid ()
+          EmptyString = ""
           Value = rand ()
           Tuple = rand (), rand ()
           Map = seq { for _ in 0L .. rand () % 5L -> "K" + guid (), rand () } |> Map.ofSeq

From 688212c5c32c918ce161a2a441e7b660faca0d9b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dan=C3=ADel=20P=2E=20Purkh=C3=BAs?= <purkhusid@gmail.com>
Date: Thu, 5 Sep 2024 15:15:33 +0000
Subject: [PATCH 2/2] Add test for empty key values

---
 .../SimpleTableOperationTests.fs                | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/tests/FSharp.AWS.DynamoDB.Tests/SimpleTableOperationTests.fs b/tests/FSharp.AWS.DynamoDB.Tests/SimpleTableOperationTests.fs
index 0e153c9..3a7e1c6 100644
--- a/tests/FSharp.AWS.DynamoDB.Tests/SimpleTableOperationTests.fs
+++ b/tests/FSharp.AWS.DynamoDB.Tests/SimpleTableOperationTests.fs
@@ -134,6 +134,23 @@ type ``Simple Table Operation Tests``(fixture: TableFixture) =
         test <@ None = deletedItem @>
         test <@ not (table.ContainsKey key) @>
 
+    [<Theory>]
+    [<InlineData("",
+                 "rangeKey",
+                 "One or more parameter values are not valid. The AttributeValue for a key attribute cannot contain an empty string value. Key: HashKey")>]
+    [<InlineData("hashKey",
+                 "",
+                 "One or more parameter values are not valid. The AttributeValue for a key attribute cannot contain an empty string value. Key: RangeKey")>]
+    [<InlineData("",
+                 "",
+                 "One or more parameter values are not valid. The AttributeValue for a key attribute cannot contain an empty string value. Key: HashKey")>]
+    let ``Operations with empty key values should fail with a DynamoDB client error`` (hashKey, rangeKey, expectedErrorMsg) =
+        let value = { mkItem () with HashKey = hashKey; RangeKey = rangeKey }
+        try
+            table.PutItem value |> ignore
+        with :? Amazon.DynamoDBv2.AmazonDynamoDBException as ex ->
+            test <@ ex.Message = expectedErrorMsg @>
+
     interface IClassFixture<TableFixture>
 
 type ``TransactWriteItems tests``(fixture: TableFixture) =