Patch experiment with checkpoints not having a name (#2805)

Author: mattseddon

extension/src/experiments/model/collect.test.ts

@@ -129,6 +129,38 @@ describe('collectExperiments', () => {
       expect(continuationCheckpoints).toHaveLength(0)
     }
   })
+
+  it('should handle a checkpoint tip not having a name', () => {
+    const checkpointTipWithoutAName = '3fceabdcef3c7b97c7779f8ae0c69a5542eefaf5'
+
+    const repoWithNestedCheckpoints = {
+      branchA: {
+        baseline: { data: {} },
+        [checkpointTipWithoutAName]: {
+          data: { checkpoint_tip: checkpointTipWithoutAName }
+        },
+        tip1cp1: {
+          data: { checkpoint_tip: checkpointTipWithoutAName }
+        },
+        tip1cp2: {
+          data: { checkpoint_tip: checkpointTipWithoutAName }
+        },
+        tip1cp3: {
+          data: { checkpoint_tip: checkpointTipWithoutAName }
+        }
+      },
+      workspace: { baseline: {} }
+    }
+    const acc = collectExperiments(repoWithNestedCheckpoints)
+
+    const { experimentsByBranch, checkpointsByTip } = acc
+    const [experiment] = experimentsByBranch.get('branchA') || []
+
+    expect(experiment.id).toStrictEqual(checkpointTipWithoutAName)
+    expect(
+      checkpointsByTip.get(checkpointTipWithoutAName)?.length
+    ).toStrictEqual(3)
+  })
 })
 
 describe('collectMutableRevisions', () => {

extension/src/experiments/model/collect.ts

@@ -118,7 +118,10 @@ const getCheckpointTipId = (
   if (!checkpointTip) {
     return
   }
-  return experimentsObject[checkpointTip]?.data?.name
+
+  const tip = experimentsObject[checkpointTip]?.data
+
+  return tip?.name || checkpointTip
 }
 
 const transformColumns = (