fix: hide performance gains without vm telemetry

Author: edmundmiller

modules/local/render_benchmark_report/bin/benchmark_report_render.py

@@ -86,6 +86,8 @@ def render_html(
 ) -> None:
     brand = brand or load_brand()
     template = Environment(loader=BaseLoader()).from_string(REPORT_TEMPLATE)
+    run_metrics = data.get("run_metrics") or []
+    has_performance_gains = any((row or {}).get("vmCpuH") for row in run_metrics)
     html = template.render(
         generated_at=datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
         data_json=json.dumps(data, default=str),
@@ -99,6 +101,7 @@ def render_html(
         brand_white=brand["white"],
         brand_palette=brand["palette"],
         logo_svg=logo_svg or "",
+        has_performance_gains=has_performance_gains,
         **data,
     )
     output_path.write_text(html)

modules/local/render_benchmark_report/bin/benchmark_report_template.html

@@ -208,7 +208,9 @@
   <a href="#task-overview"><svg class="nav-icon"><use href="#ic-task"/></svg> Task overview</a>
   <a href="#task-instance-usage" class="l2"><svg class="nav-icon"><use href="#ic-instance"/></svg> Instance usage</a>
   <a href="#task-metrics" class="l2"><svg class="nav-icon"><use href="#ic-scatter"/></svg> Task metrics</a>
+{% if has_performance_gains %}
   <a href="#performance-gains"><svg class="nav-icon"><use href="#ic-benchmark"/></svg> Performance gains</a>
+{% endif %}
 </div>
 
 <div class="main-content">
@@ -440,6 +442,7 @@ <h2 id="task-metrics"><svg class="h-icon sm"><use href="#ic-scatter"/></svg> Tas
   </div>
 
   <!-- 6. Performance gains -->
+{% if has_performance_gains %}
   <div class="section" id="performance-gains">
     <h1><svg class="h-icon"><use href="#ic-benchmark"/></svg> Performance gains</h1>
     <p class="section-desc">Capacity mix and savings attribution across CPU and memory.</p>
@@ -507,6 +510,7 @@ <h2 id="pg-cpu-savings"><svg class="h-icon sm"><use href="#ic-chart"/></svg> Sav
     <h2 id="pg-mem-savings"><svg class="h-icon sm"><use href="#ic-chart"/></svg> Savings attribution (Memory)</h2>
     <div class="chart" id="chart-pg-mem-savings"></div>
   </div>
+{% endif %}
 
 </div>
 </div>

modules/local/render_benchmark_report/tests/test_render.py

@@ -41,12 +41,8 @@ def test_render_html(tmp_path, minimal_report_data):
     assert "realVmCpuEfficiency" in text
     assert "How process runtime is measured" in text
     assert "How task timing is measured" in text
-    assert "How savings attribution is measured" in text
-    assert "How savings layers are defined" in text
-    assert "runs without a Scheduler compute environment" in text
-    assert "Scheduler rightsize will be zero by construction" in text
-    # VM metric charts
-    assert 'id="chart-vm-alloc-cpu"' in text
+    # Performance gains section — hidden when no VM telemetry
+
     assert 'id="chart-vm-alloc-mem"' in text
     assert 'id="chart-vm-real-cpu"' in text
     assert 'id="chart-vm-real-mem"' in text
@@ -58,19 +54,31 @@ def test_render_html(tmp_path, minimal_report_data):
     assert "Real VM CPU eff %" in text
     assert "Real VM Mem eff %" in text
     assert "fmtPct(r.realVmCpuEfficiency)" in text
-    # Performance gains section
+    # Performance gains section — hidden when no VM telemetry
+    assert 'id="performance-gains"' not in text
+    assert 'href="#performance-gains"' not in text
+    assert 'id="chart-pg-cpu-mix"' not in text
+    assert 'id="chart-pg-cpu-savings"' not in text
+    assert 'target="_blank" rel="noopener noreferrer"' in text
+    assert "r.runUrl ? '<a href=\"' + r.runUrl" in text
+
+
+def test_render_performance_gains_with_vm_data(tmp_path, minimal_report_data):
+    data = dict(minimal_report_data)
+    data["run_metrics"] = [{"group": "cpu", "run_id": "run1", "vmCpuH": 10.0}]
+    out = tmp_path / "report.html"
+    render_html(data, out)
+    text = out.read_text()
     assert 'id="performance-gains"' in text
     assert 'href="#performance-gains"' in text
     assert 'id="chart-pg-cpu-mix"' in text
-    assert 'id="chart-pg-mem-mix"' in text
     assert 'id="chart-pg-cpu-savings"' in text
-    assert 'id="chart-pg-mem-savings"' in text
+    assert "How savings attribution is measured" in text
+    assert "How savings layers are defined" in text
+    assert "runs without a Scheduler compute environment" in text
+    assert "Scheduler rightsize will be zero by construction" in text
     assert "CPU capacity mix" in text
     assert "Savings attribution (CPU) by layer" in text
-    assert "schedulerRightsizedCpuH" in text
-    assert "vmPackingSlackCpuH" in text
-    assert 'target="_blank" rel="noopener noreferrer"' in text
-    assert "r.runUrl ? '<a href=\"' + r.runUrl" in text
 
 
 def test_render_includes_combined_runtime_section(tmp_path, minimal_report_data):