Add checks for different number of dimensions

Author: carlosdelest

x-pack/plugin/esql/src/internalClusterTest/java/org/elasticsearch/xpack/esql/vector/VectorSimilarityFunctionsIT.java

@@ -16,6 +16,7 @@
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.xcontent.XContentBuilder;
 import org.elasticsearch.xcontent.XContentFactory;
+import org.elasticsearch.xpack.esql.EsqlClientException;
 import org.elasticsearch.xpack.esql.EsqlTestUtils;
 import org.elasticsearch.xpack.esql.action.AbstractEsqlIntegTestCase;
 import org.elasticsearch.xpack.esql.action.EsqlCapabilities;
@@ -96,6 +97,18 @@ public void testSimilarityBetweenConstantVectorAndField() {
         }
     }
 
+    public void testDifferentDimensions() {
+        var randomVector = randomVectorArray(randomValueOtherThan(numDims, () -> randomIntBetween(32, 64) * 2));
+        var query = String.format(Locale.ROOT, """
+                FROM test
+                | EVAL similarity = %s(left_vector, %s)
+                | KEEP left_vector, similarity
+            """, functionName, Arrays.toString(randomVector));
+
+        EsqlClientException iae = expectThrows(EsqlClientException.class, () -> { run(query); });
+        assertTrue(iae.getMessage().contains("Vectors must have the same dimensions"));
+    }
+
     @SuppressWarnings("unchecked")
     public void testSimilarityBetweenConstantVectors() {
         var vectorLeft = randomVectorArray();
@@ -155,8 +168,12 @@ private List<Float> randomVector() {
 
     private float[] randomVectorArray() {
         assert numDims != 0 : "numDims must be set before calling randomVectorArray()";
-        float[] vector = new float[numDims];
-        for (int j = 0; j < numDims; j++) {
+        return randomVectorArray(numDims);
+    }
+
+    private static float[] randomVectorArray(int dimensions) {
+        float[] vector = new float[dimensions];
+        for (int j = 0; j < dimensions; j++) {
             vector[j] = randomFloat();
         }
         return vector;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/vector/VectorSimilarityFunction.java

@@ -14,6 +14,7 @@
 import org.elasticsearch.compute.data.Page;
 import org.elasticsearch.compute.operator.DriverContext;
 import org.elasticsearch.compute.operator.EvalOperator;
+import org.elasticsearch.xpack.esql.EsqlClientException;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
 import org.elasticsearch.xpack.esql.core.expression.TypeResolutions;
 import org.elasticsearch.xpack.esql.core.tree.Source;
@@ -124,8 +125,13 @@ public Block eval(Page page) {
 
                         int dimensions = leftBlock.getValueCount(0);
                         int dimsRight = rightBlock.getValueCount(0);
-                        assert dimensions == dimsRight
-                            : "Left and right vector must have the same value count, but got left: " + dimensions + ", right: " + dimsRight;
+                        if (dimensions != dimsRight) {
+                            throw new EsqlClientException(
+                                "Vectors must have the same dimensions; first vector has {}, and second has {}",
+                                dimensions,
+                                dimsRight
+                            );
+                        }
                         float[] leftScratch = new float[dimensions];
                         float[] rightScratch = new float[dimensions];
                         try (DoubleVector.Builder builder = context.blockFactory().newDoubleVectorBuilder(positionCount * dimensions)) {