fix: Create span when no active span for error. (#191)

## Summary

Create a span for recording errors when one doesn't exist already.

Also added a unit test suite for the singleton instance.

## How did you test this change?

Unit tests.

## Are there any deployment considerations?

<!--
 Backend - Do we need to consider migrations or backfilling data?
-->

Author: kinyoklion

sdk/@launchdarkly/observability-python/.gitignore

@@ -1,4 +1,5 @@
 .coverage
 coverage.xml
 .coveragerc
-docs/
+docs/
+.vscode/

sdk/@launchdarkly/observability-python/ldobserve/_otel/configuration.py

@@ -80,6 +80,10 @@ def log_handler(self) -> LoggingHandler:
     def meter(self) -> Meter:
         return self._meter
 
+    @property
+    def tracer(self) -> otel_trace.Tracer:
+        return self._tracer
+
     def __init__(self, project_id: str, config: _ProcessedConfig):
         self._project_id = project_id
         self._config = config

sdk/@launchdarkly/observability-python/ldobserve/observe.py

@@ -18,7 +18,8 @@
     UpDownCounter as APIUpDownCounter,
 )
 
-_name = "launchdarkly-observability"
+_NAME = "launchdarkly-observability"
+_ERROR_NAME = "launchdarkly.error"
 
 
 class _ObserveInstance:
@@ -45,22 +46,26 @@ def __init__(self, project_id: str, otel_configuration: _OTELConfiguration):
         self._logger.propagate = False
         self._logger.addHandler(otel_configuration.log_handler)
         self._project_id = project_id
-        self._tracer = trace.get_tracer(_name)
+        self._tracer = otel_configuration.tracer
 
     def record_exception(
         self, error: Exception, attributes: typing.Optional[Attributes] = None
     ):
+        if error is None:
+            return  # Nothing to record
+
         span = trace.get_current_span()
-        if not span:
-            self._logger.error("observe.record_exception called without a span context")
-            return
+        ctx = contextlib.nullcontext(span)
+        if not span or not span.is_recording():
+            ctx = self.start_span(_ERROR_NAME)
 
-        attrs = {}
-        if attributes:
-            addedAttributes = flatten_dict(attributes, sep=".")
-            attrs.update(addedAttributes)
+        with ctx as span:
+            attrs = {}
+            if attributes:
+                addedAttributes = flatten_dict(attributes, sep=".")
+                attrs.update(addedAttributes)
 
-        span.record_exception(error, attrs)
+            span.record_exception(error, attrs)
 
     def record_metric(
         self, name: str, value: float, attributes: typing.Optional[Attributes] = None
@@ -128,7 +133,7 @@ def start_span(
         Yields:
             The newly-created span.
         """
-        with trace.get_tracer(__name__).start_as_current_span(
+        with self._tracer.start_as_current_span(
             name,
             attributes=attributes,
             record_exception=record_exception,