Always call BigQuery API with useLegacySql set to false (#26)

lib/req_bigquery.ex

@@ -127,6 +127,7 @@ defmodule ReqBigQuery do
         query
         |> build_request_body(options[:default_dataset_id])
         |> Map.put(:maxResults, options[:max_results])
+        |> Map.put(:useLegacySql, false)
 
       %{request | url: uri}
       |> Request.merge_options(auth: {:bearer, token}, json: json)
@@ -157,7 +158,7 @@ defmodule ReqBigQuery do
   end
 
   defp build_request_body(query, dataset) when dataset in ["", nil] do
-    %{query: query, useLegacySql: false}
+    %{query: query}
   end
 
   defp build_request_body(query, dataset) when is_binary(query) do

test/integration_test.exs

@@ -2,6 +2,38 @@ defmodule IntegrationTest do
   use ExUnit.Case, async: true
   @moduletag :integration
 
+  test "returns the Google BigQuery's response when BigQuery's GoogleSQL is used and default dataset is attached",
+       %{
+         test: goth
+       } do
+    credentials =
+      System.get_env("GOOGLE_APPLICATION_CREDENTIALS", "credentials.json")
+      |> File.read!()
+      |> Jason.decode!()
+
+    project_id = System.get_env("PROJECT_ID", credentials["project_id"])
+
+    source = {:service_account, credentials, []}
+    start_supervised!({Goth, name: goth, source: source, http_client: &Req.request/1})
+
+    # DATE_DIFF is not supported by BigQuery's legacy SQL.
+    # But the default value of useLegacySql is true.
+    # So the query fails if it is not changed to false.
+    query = """
+    SELECT *
+    FROM `bigquery-public-data.wikipedia.table_bands`
+    WHERE DATE_DIFF(CURRENT_DATE, CAST(datehour AS DATE), DAY) > 14
+    LIMIT 10
+    """
+
+    response =
+      Req.new()
+      |> ReqBigQuery.attach(project_id: project_id, default_dataset_id: "wikipedia", goth: goth)
+      |> Req.post!(bigquery: query)
+
+    assert response.status == 200
+  end
+
   test "returns the Google BigQuery's response", %{test: goth} do
     credentials =
       System.get_env("GOOGLE_APPLICATION_CREDENTIALS", "credentials.json")

test/req_bigquery_test.exs

@@ -18,7 +18,8 @@ defmodule ReqBigQueryTest do
       assert Jason.decode!(request.body) == %{
                "defaultDataset" => %{"datasetId" => "my_awesome_dataset"},
                "query" => "select * from iris",
-               "maxResults" => 10000
+               "maxResults" => 10000,
+               "useLegacySql" => false
              }
 
       assert URI.to_string(request.url) ==