feat(go_server): Don't apply default values for labels in labeled_booleans

glean_parser/templates/go_server.jinja2

@@ -227,7 +227,7 @@ func (e {{ event|event_type_name }}) gleanEvent() gleanEvent {
 // {{ metric.description|clean_string }}
 type {{ metric|metric_argument_name }} struct {
     {% for label in metric.ordered_labels %}
-    {{ label|event_extra_name }} bool // {{ label }}
+    {{ label|event_extra_name }} *bool `json:"{{ label }},omitempty"`
     {% endfor %}
 }
 {% endfor %}
@@ -277,12 +277,6 @@ func (g GleanEventsLogger) Record{{ ping|ping_type_name }}(
         {% for metric in metrics %}
             {% if metric_type == 'datetime' %}
             "{{ metric|metric_name }}": params.{{ metric|metric_argument_name }}.Format("2006-01-02T15:04:05.000Z"),
-            {% elif metric_type == 'labeled_boolean' %}
-            "{{ metric|metric_name }}": map[string]bool{
-                {% for label in metric.ordered_labels %}
-                "{{ label }}": params.{{ metric|metric_argument_name }}.{{ label|event_extra_name }},
-                {% endfor %}
-            },
             {% else %}
             "{{ metric|metric_name }}": params.{{ metric|metric_argument_name }},
             {% endif %}

tests/data/go_server_labeled_boolean_metrics.yaml

@@ -13,6 +13,7 @@ telemetry:
       - feature_one
       - feature_two
       - feature_three
+      - feature_four
     bugs:
       - https://bugzilla.mozilla.org/show_bug.cgi?id=1234567
     data_reviews:

tests/test_go_server.py

@@ -77,19 +77,13 @@ def test_parser_go_server_labeled_boolean(tmp_path):
 
         # Check that the labeled_boolean struct type was generated
         assert "type TelemetryFeatureFlags struct {" in content
-        assert "FeatureOne bool" in content
-        assert "FeatureTwo bool" in content
-        assert "FeatureThree bool" in content
+        assert "FeatureOne *bool" in content
+        assert "FeatureTwo *bool" in content
+        assert "FeatureThree *bool" in content
 
         # Check that it's used in the ping struct
         assert "TelemetryFeatureFlags TelemetryFeatureFlags" in content
 
-        # Check that serialization includes map creation
-        assert "map[string]bool{" in content
-        assert '"feature_one":' in content
-        assert '"feature_two":' in content
-        assert '"feature_three":' in content
-
 
 def test_parser_go_server_events_only(tmp_path):
     """Test that parser works for definitions that only use events ping"""
@@ -399,16 +393,19 @@ def test_run_logging_labeled_boolean(tmp_path):
 
     code = """
     _ = time.Now() // satisfy Go's unused import check for "time"
+    t := true
+    f := false
     logger.RecordEventsPing(
         glean.RequestInfo{
             UserAgent: "glean-test/1.0",
             IpAddress: "127.0.0.1",
         },
         glean.EventsPing{
             TelemetryFeatureFlags: glean.TelemetryFeatureFlags{
-                FeatureOne:   true,
-                FeatureTwo:   false,
-                FeatureThree: true,
+                FeatureOne:   &t,
+                FeatureTwo:   &f,
+                FeatureThree: nil, // valid label on metric but this request had no value for it
+                // FeatureFour omitted to illustrate zero value behavior
             },
         },
     )
@@ -437,13 +434,14 @@ def test_run_logging_labeled_boolean(tmp_path):
         output.getvalue()
     )
 
-    # Check that labeled_boolean is properly serialized as a map
+    # Check that labeled_boolean is properly serialized
     labeled_boolean_metrics = payload["metrics"]["labeled_boolean"]
     assert "telemetry.feature_flags" in labeled_boolean_metrics
     feature_flags = labeled_boolean_metrics["telemetry.feature_flags"]
     assert feature_flags["feature_one"] is True
     assert feature_flags["feature_two"] is False
-    assert feature_flags["feature_three"] is True
+    assert feature_flags.get("feature_three") is None
+    assert feature_flags.get("feature_four") is None
 
 
 @pytest.mark.go_dependency