fix(sdk-trace-base): ensure attribute value length limit is enforced …

…on span creation (open-telemetry#4417)

* fix(sdk-trace-base): ensure attribute value length limit is enforced on span creation

* fix(changelog): add changelog entry

CHANGELOG.md

@@ -13,6 +13,8 @@ For experimental package changes, see the [experimental CHANGELOG](experimental/
 
 ### :bug: (Bug Fix)
 
+* fix(sdk-trace-base): ensure attribute value length limit is enforced on span creation [#4417](https://github.com/open-telemetry/opentelemetry-js/pull/4417) @pichlermarc
+
 ### :books: (Refine Doc)
 
 ### :house: (Internal)

packages/opentelemetry-sdk-trace-base/src/Span.ts

@@ -120,15 +120,15 @@ export class Span implements APISpan, ReadableSpan {
     this.resource = parentTracer.resource;
     this.instrumentationLibrary = parentTracer.instrumentationLibrary;
     this._spanLimits = parentTracer.getSpanLimits();
+    this._attributeValueLengthLimit =
+      this._spanLimits.attributeValueLengthLimit || 0;
 
     if (attributes != null) {
       this.setAttributes(attributes);
     }
 
     this._spanProcessor = parentTracer.getActiveSpanProcessor();
     this._spanProcessor.onStart(this, context);
-    this._attributeValueLengthLimit =
-      this._spanLimits.attributeValueLengthLimit || 0;
   }
 
   spanContext(): SpanContext {

packages/opentelemetry-sdk-trace-base/test/common/Span.test.ts

@@ -369,6 +369,22 @@ describe('Span', () => {
           span.setAttribute('attr-non-string', true);
           assert.strictEqual(span.attributes['attr-non-string'], true);
         });
+
+        it('should truncate value when attributes are passed to the constructor', () => {
+          const span = new Span(
+            tracer,
+            ROOT_CONTEXT,
+            name,
+            spanContext,
+            SpanKind.CLIENT,
+            undefined,
+            undefined,
+            undefined,
+            undefined,
+            { 'attr-with-more-length': 'abcdefgh' }
+          );
+          assert.strictEqual(span.attributes['attr-with-more-length'], 'abcde');
+        });
       });
 
       describe('when "attributeValueLengthLimit" option is invalid', () => {