Improved vector range argument parsing (#445)

* Better argument parsing for vector range expressions

* Update contributors

* Simplify expression cases, include test coverage for method expressions.

* Reuse GetOperand for evaluating values

---------

Co-authored-by: James Abbott <james.abbott@crispthinking.com>

Author: abbottdev

CONTRIBUTING.md

@@ -21,7 +21,7 @@ We welcome code contributions from the community, if you want to contribute code
 1. Fork this repo.
 2. Make your Code Changes.
 3. Write your tests.
-4. Use the `docker run -p 6379:6379 redis/redis-stack-server` as your local environment for running the functional tests.
+4. Use the `docker run -p 6379:6379 redis/redis-stack-server` as your local environment for running the functional tests. (Note: If your tests fail due to missing vocabulary, please run `fetch.models.sh` from the root directory until Git LFS has been resolved. These files are required for the tokenizers used by the functional tests)
 5. Verify the tests pass (there may be a couple of deployment-specific tests (e.g. Sentinel/Cluster) in Redis.OM which will fail outside of the GH environment we've setup so don't worry about those).
 6. If it's your first time contributing please add your Github handle the the Contributors section in the README.
 7. Push your changes to GitHub.

README.md

@@ -470,6 +470,7 @@ We'd love your contributions! If you want to contribute please read our [Contrib
 * [@mdrakib](https://github.com/mdrakib)
 * [@jrpavoncello](https://github.com/jrpavoncello)
 * [@axnetg](https://github.com/axnetg)
+* [@abbottdev](https://github.com/abbottdev)
 
 <!-- Logo -->
 [Logo]: images/logo.svg

src/Redis.OM/Common/ExpressionParserUtilities.cs

@@ -1014,6 +1014,8 @@ private static object GetOperand(Expression expression)
             {
                 MemberExpression me => GetValue(me.Member, ((ConstantExpression)me.Expression).Value),
                 ConstantExpression ce => ce.Value,
+                UnaryExpression ue when ue.NodeType == ExpressionType.Convert => Convert.ChangeType(GetOperand(ue.Operand), ue.Type),
+                MethodCallExpression me => me.Method.Invoke(me.Object, me.Arguments.Select(GetOperand).ToArray()),
                 _ => throw new InvalidOperationException("Could not determine value.")
             };
         }
@@ -1047,7 +1049,8 @@ private static string TranslateVectorRange(MethodCallExpression exp, List<object
                 bytes = vector.Embedding ?? throw new InvalidOperationException("Embedding was null");
             }
 
-            var distance = (double)((ConstantExpression)exp.Arguments[2]).Value;
+            var distance = (double)GetOperand(exp.Arguments[2]);
+
             var distanceArgName = parameters.Count.ToString();
             parameters.Add(distance);
             var vectorArgName = parameters.Count.ToString();

test/Redis.OM.Vectorizer.Tests/VectorizerFunctionalTests.cs

@@ -17,6 +17,7 @@ public VectorizerFunctionalTests()
     public void Test()
     {
         var connection = _provider.Connection;
+        connection.DropIndex(typeof(DocWithVectors));
         connection.CreateIndex(typeof(DocWithVectors));
         connection.Set(new DocWithVectors
         {
@@ -33,6 +34,85 @@ public void Test()
         collection.NearestNeighbors(x => x.Sentence!, 5, "Hello world this really is Hal.");
     }
 
+    [Fact]
+    public void VectorRangeUnaryExpressionTest()
+    {
+        var connection = _provider.Connection;
+        connection.DropIndex(typeof(DocWithVectors));
+        connection.CreateIndex(typeof(DocWithVectors));
+        connection.Set(new DocWithVectors
+        {
+            Sentence = Vector.Of("Hello world this is Hal."),
+            ImagePath = Vector.Of("hal.jpg")
+        });
+        
+        var variableRange = 5;
+        var collection = new RedisCollection<DocWithVectors>(connection);
+
+        // images
+        var res = collection.Where(x => x.Sentence!.VectorRange("Hal", variableRange, "score"));
+
+        Assert.NotNull(res.First().Scores!.RangeScore);
+        Assert.InRange(res.First().Scores!.RangeScore!.Value, 0, 1);
+
+        // sentences
+        collection.NearestNeighbors(x => x.Sentence!, variableRange, "Hello world this really is Hal.");
+    }
+
+    [Fact]
+    public void VectorRangeMemberExpressionTest()
+    {
+        var connection = _provider.Connection;
+        connection.DropIndex(typeof(DocWithVectors));
+        connection.CreateIndex(typeof(DocWithVectors));
+        connection.Set(new DocWithVectors
+        {
+            Sentence = Vector.Of("Hello world this is Hal."),
+            ImagePath = Vector.Of("hal.jpg")
+        });
+        
+        double variableRange = 5 + 5;
+        var collection = new RedisCollection<DocWithVectors>(connection);
+
+        // images
+        
+        var res = collection.Where(x => x.Sentence!.VectorRange("Hal", variableRange, "score"));
+
+        Assert.NotNull(res.First().Scores!.RangeScore);
+        Assert.InRange(res.First().Scores!.RangeScore!.Value, 0, 1);
+
+        // sentences
+        collection.NearestNeighbors(x => x.Sentence!, 5, "Hello world this really is Hal.");
+    }
+
+    private static double GetVectorRange() => 5;
+    private static int GetKnnNeighbours() => 5;
+
+    [Fact]
+    public void VectorRangeMethodExpressionTest()
+    {
+        var connection = _provider.Connection;
+        connection.DropIndex(typeof(DocWithVectors));
+        connection.CreateIndex(typeof(DocWithVectors));
+        connection.Set(new DocWithVectors
+        {
+            Sentence = Vector.Of("Hello world this is Hal."),
+            ImagePath = Vector.Of("hal.jpg")
+        });
+        
+        var collection = new RedisCollection<DocWithVectors>(connection);
+
+        // images
+        
+        var res = collection.Where(x => x.Sentence!.VectorRange("Hal", GetVectorRange(), "score"));
+
+        Assert.NotNull(res.First().Scores!.RangeScore);
+        Assert.InRange(res.First().Scores!.RangeScore!.Value, 0, 1);
+
+        // sentences
+        collection.NearestNeighbors(x => x.Sentence!, GetKnnNeighbours(), "Hello world this really is Hal.");
+    }
+
     [Fact]
     public void SemanticCaching()
     {