Add another test for ReadOnlyRun

tests/e2e/test_read_only_run.py

@@ -7,13 +7,21 @@
     timezone,
 )
 
+from neptune_fetcher import ReadOnlyRun
+
 NEPTUNE_PROJECT = os.getenv("NEPTUNE_E2E_PROJECT")
 
 
 def unique_path(prefix):
     return f"{prefix}__{datetime.now(timezone.utc).isoformat('-', 'seconds')}__{str(uuid.uuid4())[-4:]}"
 
 
+def refresh(ro_run: ReadOnlyRun):
+    """Create a new ReadOnlyRun instance with the same project and custom_id,
+    which is basically a "refresh" operation"""
+    return ReadOnlyRun(read_only_project=ro_run.project, custom_id=ro_run["sys/custom_run_id"].fetch())
+
+
 def random_series(length=10, start_step=0):
     """Return a 2-tuple of step and value lists, both of length `length`"""
     assert length > 0
@@ -85,7 +93,7 @@ def test_series_no_prefetch(run, ro_run):
     assert df["value"].tolist() == values
 
 
-def test_series_with_prefetch(run, ro_run):
+def test_single_series_with_prefetch(run, ro_run):
     path = unique_path("test_series/series_with_prefetch")
 
     steps, values = random_series()
@@ -95,13 +103,31 @@ def test_series_with_prefetch(run, ro_run):
 
     run.wait_for_processing()
 
-    ro_run.prefetch_series_values([path])
+    ro_run.prefetch_series_values([path], use_threads=True)
     df = ro_run[path].fetch_values()
 
     assert df["step"].tolist() == steps
     assert df["value"].tolist() == values
 
 
+def test_multiple_series_with_prefetch(run, ro_run):
+    path_base = unique_path("test_series/many_series_with_prefetch")
+    data = {f"{path_base}-{i}": i for i in range(20)}
+
+    run.log_metrics(data, step=1)
+    run.wait_for_processing()
+
+    ro_run = refresh(ro_run)
+    paths = [p for p in ro_run.field_names if p.startswith(path_base)]
+    assert len(paths) == len(data), "Not all data was logged"
+
+    ro_run.prefetch_series_values(paths, use_threads=True)
+    for path in paths:
+        df = ro_run[path].fetch_values()
+        assert df["step"].tolist() == [1]
+        assert df["value"].tolist() == [data[path]]
+
+
 def test_series_fetch_and_append(run, ro_run):
     """Fetch a series, then append, then fetch again -- the new data points should be there"""