feat: non-experimental before_send_metric option (#5064)

Add a stable `before_send_metric` option. If no value is specified, the existing experimental callback is invoked instead.

Author: alexander-alderman-webb

sentry_sdk/consts.py

@@ -1012,6 +1012,7 @@ def __init__(
         before_send_log=None,  # type: Optional[Callable[[Log, Hint], Optional[Log]]]
         trace_ignore_status_codes=frozenset(),  # type: AbstractSet[int]
         enable_metrics=True,  # type: bool
+        before_send_metric=None,  # type: Optional[Callable[[Metric, Hint], Optional[Metric]]]
     ):
         # type: (...) -> None
         """Initialize the Sentry SDK with the given parameters. All parameters described here can be used in a call to `sentry_sdk.init()`.

sentry_sdk/utils.py

@@ -2060,4 +2060,6 @@ def get_before_send_metric(options):
     if options is None:
         return None
 
-    return options["_experiments"].get("before_send_metric")
+    return options.get("before_send_metric") or options["_experiments"].get(
+        "before_send_metric"
+    )

tests/test_metrics.py

@@ -168,6 +168,45 @@ def test_metrics_tracing_without_performance(sentry_init, capture_envelopes):
 def test_metrics_before_send(sentry_init, capture_envelopes):
     before_metric_called = False
 
+    def _before_metric(record, hint):
+        nonlocal before_metric_called
+
+        assert set(record.keys()) == {
+            "timestamp",
+            "trace_id",
+            "span_id",
+            "name",
+            "type",
+            "value",
+            "unit",
+            "attributes",
+        }
+
+        if record["name"] == "test.skip":
+            return None
+
+        before_metric_called = True
+        return record
+
+    sentry_init(
+        before_send_metric=_before_metric,
+    )
+    envelopes = capture_envelopes()
+
+    sentry_sdk.metrics.count("test.skip", 1)
+    sentry_sdk.metrics.count("test.keep", 1)
+
+    get_client().flush()
+
+    metrics = envelopes_to_metrics(envelopes)
+    assert len(metrics) == 1
+    assert metrics[0]["name"] == "test.keep"
+    assert before_metric_called
+
+
+def test_metrics_experimental_before_send(sentry_init, capture_envelopes):
+    before_metric_called = False
+
     def _before_metric(record, hint):
         nonlocal before_metric_called