Add multiple filters test

Author: carlosdelest

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/optimizer/LocalPhysicalPlanOptimizerTests.java

@@ -1871,6 +1871,42 @@ public void testKnnPrefilters() {
         assertEquals(expectedQuery.toString(), queryExec.query().toString());
     }
 
+    public void testKnnPrefiltersWithMultipleFilters() {
+        assumeTrue("knn must be enabled", EsqlCapabilities.Cap.KNN_FUNCTION_V3.isEnabled());
+
+        String query = """
+            from test
+            | where knn(dense_vector, [0, 1, 2], 10)
+            | where integer > 10
+            | where keyword == "test"
+            """;
+        var plan = plannerOptimizer.plan(query, IS_SV_STATS, makeAnalyzer("mapping-all-types.json"));
+
+        var limit = as(plan, LimitExec.class);
+        var exchange = as(limit.child(), ExchangeExec.class);
+        var project = as(exchange.child(), ProjectExec.class);
+        var field = as(project.child(), FieldExtractExec.class);
+        var queryExec = as(field.child(), EsQueryExec.class);
+        var integerFilter = wrapWithSingleQuery(query, unscore(rangeQuery("integer").gt(10)), "integer", new Source(3, 8, "integer > 10"));
+        var keywordFilter = wrapWithSingleQuery(
+            query,
+            unscore(termQuery("keyword", "test")),
+            "keyword",
+            new Source(4, 8, "keyword == \"test\"")
+        );
+        QueryBuilder expectedFilterQueryBuilder = boolQuery().must(integerFilter).must(keywordFilter);
+        KnnVectorQueryBuilder expectedKnnQueryBuilder = new KnnVectorQueryBuilder(
+            "dense_vector",
+            new float[] { 0, 1, 2 },
+            10,
+            null,
+            null,
+            null
+        ).addFilterQuery(expectedFilterQueryBuilder);
+        var expectedQuery = boolQuery().must(expectedKnnQueryBuilder).must(integerFilter).must(keywordFilter);
+        assertEquals(expectedQuery.toString(), queryExec.query().toString());
+    }
+
     public void testPushDownConjunctionsToKnnPrefilter() {
         assumeTrue("knn must be enabled", EsqlCapabilities.Cap.KNN_FUNCTION_V3.isEnabled());
 

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/optimizer/LogicalPlanOptimizerTests.java

@@ -7877,6 +7877,29 @@ public void testPushDownConjunctionsToKnnPrefilter() {
         var esRelation = as(filter.child(), EsRelation.class);
     }
 
+    public void testPushDownMultipleFiltersToKnnPrefilter() {
+        assumeTrue("knn must be enabled", EsqlCapabilities.Cap.KNN_FUNCTION_V3.isEnabled());
+
+        var query = """
+            from test
+            | where knn(dense_vector, [0, 1, 2], 10)
+            | where integer > 10
+            | where keyword == "test"
+            """;
+        var optimized = planTypes(query);
+
+        var limit = as(optimized, Limit.class);
+        var filter = as(limit.child(), Filter.class);
+        var firstAnd = as(filter.condition(), And.class);
+        var knn = as(firstAnd.left(), Knn.class);
+        var prefilterAnd = as(firstAnd.right(), And.class);
+        as(prefilterAnd.left(), GreaterThan.class);
+        as(prefilterAnd.right(), Equals.class);
+        List<Expression> filterExpressions = knn.filterExpressions();
+        assertThat(filterExpressions.size(), equalTo(1));
+        assertThat(prefilterAnd, equalTo(filterExpressions.get(0)));
+    }
+
     public void testNotPushDownDisjunctionsToKnnPrefilter() {
         assumeTrue("knn must be enabled", EsqlCapabilities.Cap.KNN_FUNCTION_V3.isEnabled());