Handle the case when no frames are captured and JSON printed

joerick · Jan 30, 2019 · 470d4a2 · 470d4a2
1 parent af35bab
commit 470d4a2
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/html_renderer/src/App.vue b/html_renderer/src/App.vue
@@ -59,15 +59,15 @@ export default {
   },
   computed: {
     rootFrame() {
-      if (this.session) {
+      if (this.session && this.session.root_frame) {
         return new FrameModel(this.session.root_frame)
       }
     }
   },
   watch: {
     session: {
       handler() {
-        if (!this.session) {
+        if (!this.session || !this.rootFrame) {
           document.title = 'Pyinstrument';
           return;
         }

diff --git a/pyinstrument/renderers/jsonrenderer.py b/pyinstrument/renderers/jsonrenderer.py
@@ -9,6 +9,8 @@
 
 class JSONRenderer(Renderer):
     def render_frame(self, frame):
+        if frame is None:
+            return u'null'
         # we don't use the json module because it uses 2x stack frames, so 
         # crashes on deep but valid call stacks