[R] Add order_by support to mlflow_search_runs (mlflow#1485)

docs/source/R-api.rst

@@ -1227,7 +1227,8 @@ Metric and Param keys.
 .. code:: r
 
    mlflow_search_runs(filter = NULL, run_view_type = c("ACTIVE_ONLY",
-     "DELETED_ONLY", "ALL"), experiment_ids = NULL, client = NULL)
+     "DELETED_ONLY", "ALL"), experiment_ids = NULL, order_by = list(),
+     client = NULL)
 
 .. _arguments-28:
 
@@ -1252,6 +1253,9 @@ Arguments
 |                               | search over. Attempts to use active  |
 |                               | experiment if not specified.         |
 +-------------------------------+--------------------------------------+
+| ``order_by``                  | List of properties to order by.      |
+|                               | Example: “metrics.acc DESC”.         |
++-------------------------------+--------------------------------------+
 | ``client``                    | (Optional) An MLflow client object   |
 |                               | returned from                        |
 |                               | `mlflow_client <#mlflow-client>`__ . |

mlflow/R/mlflow/R/tracking-runs.R

@@ -253,10 +253,13 @@ mlflow_get_metric_history <- function(metric_key, run_id = NULL, client = NULL)
 #' @param filter A filter expression over params, metrics, and tags, allowing returning a subset of runs.
 #'   The syntax is a subset of SQL which allows only ANDing together binary operations between a param/metric/tag and a constant.
 #' @param run_view_type Run view type.
+#' @param order_by List of properties to order by. Example: "metrics.acc DESC".
 #'
 #' @export
 mlflow_search_runs <- function(filter = NULL,
-                               run_view_type = c("ACTIVE_ONLY", "DELETED_ONLY", "ALL"), experiment_ids = NULL,
+                               run_view_type = c("ACTIVE_ONLY", "DELETED_ONLY", "ALL"),
+                               experiment_ids = NULL,
+                               order_by = list(),
                                client = NULL) {
   experiment_ids <- resolve_experiment_id(experiment_ids)
   # If we get back a single experiment ID, e.g. the active experiment ID, convert it to a list
@@ -272,7 +275,8 @@ mlflow_search_runs <- function(filter = NULL,
   response <- mlflow_rest("runs", "search", client = client, verb = "POST", data = list(
     experiment_ids = experiment_ids,
     filter = filter,
-    run_view_type = run_view_type
+    run_view_type = run_view_type,
+    order_by = cast_string_list(order_by)
   ))
 
   runs_list <- response$run %>%

mlflow/R/mlflow/tests/testthat/test-tracking-runs.R

@@ -249,6 +249,15 @@ test_that("mlflow_search_runs() works", {
   expect_equal(nrow(mlflow_search_runs(filter = "metrics.test > 10", experiment_ids = list("0"))), 1)
   expect_equal(nrow(mlflow_search_runs(filter = "metrics.test < 20", experiment_ids = list("0"))), 1)
   expect_equal(nrow(mlflow_search_runs(filter = "metrics.test > 20", experiment_ids = list("0"))), 0)
+
+  search <- mlflow_search_runs(order_by = "metrics.test", experiment_ids = list("0"))
+  expect_equal(search$metrics[[1]]$value[1], 10)
+  expect_equal(search$metrics[[2]]$value[1], 20)
+
+  search <- mlflow_search_runs(order_by = list("metrics.test DESC"), experiment_ids = list("0"))
+  expect_equal(search$metrics[[1]]$value[1], 20)
+  expect_equal(search$metrics[[2]]$value[1], 10)
+
   mlflow_set_experiment("new-experiment")
   expect_equal(nrow(mlflow_search_runs()), 0)
   with(mlflow_start_run(), {