fixed a bug where when executing on a single shard and sorting terms agg based on sub metric agg, the order (asc/desc) is not respected

 - fixed tests for terms order

Closes #4951

Author: uboness

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalOrder.java

@@ -215,7 +215,7 @@ public int compare(Terms.Bucket o1, Terms.Bucket o2) {
                         if (v1 == Double.NaN) {
                             return asc ? 1 : -1;
                         }
-                        return Double.compare(v1, v2);
+                        return asc ? Double.compare(v1, v2) : Double.compare(v2, v1);
                     }
                 };
             }
@@ -230,7 +230,7 @@ public int compare(Terms.Bucket o1, Terms.Bucket o2) {
                     if (v1 == Double.NaN) {
                         return asc ? 1 : -1;
                     }
-                    return Double.compare(v1, v2);
+                    return asc ? Double.compare(v1, v2) : Double.compare(v2, v1);
                 }
             };
         }

src/test/java/org/elasticsearch/search/aggregations/bucket/StringTermsTests.java

@@ -800,14 +800,15 @@ public void singleValuedField_OrderedBySingleValueSubAggregationAsc() throws Exc
         assertThat(terms.getName(), equalTo("terms"));
         assertThat(terms.getBuckets().size(), equalTo(5));
 
-        for (int i = 0; i < 5; i++) {
-            Terms.Bucket bucket = terms.getBucketByKey("val" + i);
+        int i = 0;
+        for (Terms.Bucket bucket : terms.getBuckets()) {
             assertThat(bucket, notNullValue());
             assertThat(key(bucket), equalTo("val" + i));
             assertThat(bucket.getDocCount(), equalTo(1l));
             Avg avg = bucket.getAggregations().get("avg_i");
             assertThat(avg, notNullValue());
             assertThat(avg.getValue(), equalTo((double) i));
+            i++;
         }
     }
 
@@ -911,16 +912,16 @@ public void singleValuedField_OrderedBySingleValueSubAggregationDesc() throws Ex
         assertThat(terms.getName(), equalTo("terms"));
         assertThat(terms.getBuckets().size(), equalTo(5));
 
-        for (int i = 4; i >= 0; i--) {
-
-            Terms.Bucket bucket = terms.getBucketByKey("val" + i);
+        int i = 4;
+        for (Terms.Bucket bucket : terms.getBuckets()) {
             assertThat(bucket, notNullValue());
             assertThat(key(bucket), equalTo("val" + i));
             assertThat(bucket.getDocCount(), equalTo(1l));
 
             Avg avg = bucket.getAggregations().get("avg_i");
             assertThat(avg, notNullValue());
             assertThat(avg.getValue(), equalTo((double) i));
+            i--;
         }
 
     }
@@ -943,15 +944,16 @@ public void singleValuedField_OrderedByMultiValueSubAggregationAsc() throws Exce
         assertThat(terms.getName(), equalTo("terms"));
         assertThat(terms.getBuckets().size(), equalTo(5));
 
-        for (int i = 0; i < 5; i++) {
-            Terms.Bucket bucket = terms.getBucketByKey("val" + i);
+        int i = 0;
+        for (Terms.Bucket bucket : terms.getBuckets()) {
             assertThat(bucket, notNullValue());
             assertThat(key(bucket), equalTo("val" + i));
             assertThat(bucket.getDocCount(), equalTo(1l));
 
             Stats stats = bucket.getAggregations().get("stats");
             assertThat(stats, notNullValue());
             assertThat(stats.getMax(), equalTo((double) i));
+            i++;
         }
 
     }
@@ -974,15 +976,16 @@ public void singleValuedField_OrderedByMultiValueSubAggregationDesc() throws Exc
         assertThat(terms.getName(), equalTo("terms"));
         assertThat(terms.getBuckets().size(), equalTo(5));
 
-        for (int i = 4; i >= 0; i--) {
-            Terms.Bucket bucket = terms.getBucketByKey("val" + i);
+        int i = 4;
+        for (Terms.Bucket bucket : terms.getBuckets()) {
             assertThat(bucket, notNullValue());
             assertThat(key(bucket), equalTo("val" + i));
             assertThat(bucket.getDocCount(), equalTo(1l));
 
             Stats stats = bucket.getAggregations().get("stats");
             assertThat(stats, notNullValue());
             assertThat(stats.getMax(), equalTo((double) i));
+            i--;
         }
 
     }
@@ -994,7 +997,7 @@ public void singleValuedField_OrderedByMultiValueExtendedStatsAsc() throws Excep
                 .addAggregation(terms("terms")
                         .executionHint(randomExecutionHint())
                         .field(SINGLE_VALUED_FIELD_NAME)
-                        .order(Terms.Order.aggregation("stats.variance", asc))
+                        .order(Terms.Order.aggregation("stats.sum_of_squares", asc))
                         .subAggregation(extendedStats("stats").field("i"))
                 ).execute().actionGet();
 
@@ -1005,15 +1008,16 @@ public void singleValuedField_OrderedByMultiValueExtendedStatsAsc() throws Excep
         assertThat(terms.getName(), equalTo("terms"));
         assertThat(terms.getBuckets().size(), equalTo(5));
 
-        for (int i = 0; i < 5; i++) {
-            Terms.Bucket bucket = terms.getBucketByKey("val" + i);
+        int i = 0;
+        for (Terms.Bucket bucket : terms.getBuckets()) {
             assertThat(bucket, notNullValue());
             assertThat(key(bucket), equalTo("val" + i));
             assertThat(bucket.getDocCount(), equalTo(1l));
 
             ExtendedStats stats = bucket.getAggregations().get("stats");
             assertThat(stats, notNullValue());
             assertThat(stats.getMax(), equalTo((double) i));
+            i++;
         }
 
     }