Added check for no other aggs apart from date_histogram + test

Makefile

@@ -1,4 +1,4 @@
-ELASTICMOCK_VERSION='1.8.2'
+ELASTICMOCK_VERSION='1.8.3'
 
 install:
 	pip3 install -r requirements.txt

elasticmock/fake_elasticsearch.py

@@ -803,18 +803,19 @@ def make_bucket(bucket_key, bucket):
                 "doc_count": len(bucket),
             }
 
-            for metric_key, metric_definition in aggregation["aggs"].items():
-                metric_type_str = list(metric_definition)[0]
-                metric_type = MetricType.get_metric_type(metric_type_str)
-                attr = metric_definition[metric_type_str]["field"]
-                data = [doc[attr] for doc in bucket]
-
-                if metric_type == MetricType.CARDINALITY:
-                    value = len(set(data))
-                else:
-                    raise NotImplementedError(f"Metric type '{metric_type}' not implemented")
+            if aggregation.get("aggs"):
+                for metric_key, metric_definition in aggregation["aggs"].items():
+                    metric_type_str = list(metric_definition)[0]
+                    metric_type = MetricType.get_metric_type(metric_type_str)
+                    attr = metric_definition[metric_type_str]["field"]
+                    data = [doc[attr] for doc in bucket]
+
+                    if metric_type == MetricType.CARDINALITY:
+                        value = len(set(data))
+                    else:
+                        raise NotImplementedError(f"Metric type '{metric_type}' not implemented")
 
-                out[metric_key] = {"value": value}
+                    out[metric_key] = {"value": value}
             return out
 
         agg_sources = aggregation["composite"]["sources"]

setup.py

@@ -2,7 +2,7 @@
 
 import setuptools
 
-__version__ = '1.8.2'
+__version__ = '1.8.3'
 
 # read the contents of your readme file
 from os import path

tests/fake_elasticsearch/test_search.py

@@ -420,3 +420,41 @@ def test_bucket_aggregation_date_histogram(self):
         for x, y in zip(expected, actual):
             self.assertDictEqual(x["key"], y["key"])
             self.assertEqual(x["doc_count"], y["doc_count"])
+
+    def test_bucket_aggregation_date_histogram_without_other_aggs(self):
+        start_date = datetime.datetime(2021, 12, 1, 15)
+        data = [
+            {"data_x": 1, "data_y": "a", "timestamp": start_date},
+            {"data_x": 1, "data_y": "a", "timestamp": start_date},
+            {"data_x": 1, "data_y": "a", "timestamp": start_date - datetime.timedelta(hours=1)},
+            {"data_x": 1, "data_y": "b", "timestamp": start_date - datetime.timedelta(hours=1)},
+            {"data_x": 1, "data_y": "b", "timestamp": start_date - datetime.timedelta(hours=1)},
+        ]
+        for body in data:
+            self.es.index(index='index_for_search', doc_type=DOC_TYPE, body=body)
+
+        response = self.es.search(
+            index="index_for_search",
+            doc_type=DOC_TYPE,
+            body={
+                "query": {"match_all": {}},
+                "aggs": {
+                    "stats": {
+                        "composite": {
+                            "sources": [{"histo": {"date_histogram": {"field": "timestamp"}}}],
+                            "size": 10000,
+                        },
+                    }
+                },
+            },
+        )
+
+        expected = [
+            {"key": {"histo": '2021-12-01T14:00:00'}, "doc_count": 3},
+            {"key": {"histo": '2021-12-01T15:00:00'}, "doc_count": 2},
+        ]
+        actual = response["aggregations"]["stats"]["buckets"]
+        print(actual)
+        for x, y in zip(expected, actual):
+            self.assertDictEqual(x["key"], y["key"])
+            self.assertEqual(x["doc_count"], y["doc_count"])