fix extractSpan to not rename span. fixes #170, fixes #165

Author: duncanpo

api/trace/+opentelemetry/+trace/Context.m

@@ -7,8 +7,7 @@
         function sp = extractSpan(context)
             % Extract span from context
             %    SP = OPENTELEMETRY.TRACE.CONTEXT.EXTRACTSPAN(CTXT) extracts
-            %    span SP from a context object CTXT. SP is a nonrecording span 
-            %    such that ISRECORDING(SP) returns false. If CTXT does not 
+            %    span SP from a context object CTXT. If CTXT does not 
             %    contain any spans, SP will be an invalid span with all-zero
             %    trace and span IDs.
             %

api/trace/+opentelemetry/+trace/Span.m

@@ -20,7 +20,6 @@
                 obj.Proxy = libmexclass.proxy.Proxy("Name", ...
                     "libmexclass.opentelemetry.SpanProxy", ...
                     "ConstructorArguments", {context.Proxy.ID});
-                obj.Name = "";   % unknown name when span is extracted from context, leave blank
             else   % in is a proxy object
                 obj.Proxy = proxy;
                 obj.Name = spname;

test/autotrace_examples/manual_instrumented_example/manual_instrumented_example.m

@@ -4,5 +4,10 @@
 
 % Copyright 2024 The MathWorks, Inc.
 
+% add an attribute about input
+ctx = opentelemetry.context.getCurrentContext;
+sp = opentelemetry.trace.Context.extractSpan(ctx);
+setAttributes(sp, "DataSize", n);
+
 [x, y] = generate_data(n);
 yf = best_fit_line(x,y);

test/tautotrace.m

@@ -353,7 +353,8 @@ function testAutoManualInstrument(testCase)
             at = opentelemetry.autoinstrument.AutoTrace(@manual_instrumented_example);
 
             % run the example
-            [~] = beginTrace(at, 100);
+            n = 100;
+            [~] = beginTrace(at, n);
 
             % perform test comparisons
             results = readJsonResults(testCase);
@@ -381,6 +382,11 @@ function testAutoManualInstrument(testCase)
             verifyEqual(testCase, results{1}.resourceSpans.scopeSpans.spans.parentSpanId, results{2}.resourceSpans.scopeSpans.spans.spanId);
             verifyEqual(testCase, results{3}.resourceSpans.scopeSpans.spans.parentSpanId, results{5}.resourceSpans.scopeSpans.spans.spanId);
             verifyEqual(testCase, results{4}.resourceSpans.scopeSpans.spans.parentSpanId, results{5}.resourceSpans.scopeSpans.spans.spanId);
+
+            % check attribute
+            verifyNumElements(testCase, results{6}.resourceSpans.scopeSpans.spans.attributes, 1);
+            verifyEqual(testCase, results{6}.resourceSpans.scopeSpans.spans.attributes.key, 'DataSize');
+            verifyEqual(testCase, results{6}.resourceSpans.scopeSpans.spans.attributes.value.doubleValue, n);
         end
     end
 end