docstore: fix batch Creates (#2726)

docstore/driver/util.go

@@ -61,8 +61,12 @@ func GroupActions(actions []*Action) (beforeGets, getList, writeList, afterGets
 	agets := map[interface{}]*Action{}
 	cgets := map[interface{}]*Action{}
 	writes := map[interface{}]*Action{}
+	var nilkeys []*Action
 	for _, a := range actions {
-		if a.Kind == Get {
+		if a.Key == nil {
+			// Probably a Create.
+			nilkeys = append(nilkeys, a)
+		} else if a.Kind == Get {
 			// If there was a prior write with this key, make sure this get
 			// happens after the writes.
 			if _, ok := writes[a.Key]; ok {
@@ -91,7 +95,7 @@ func GroupActions(actions []*Action) (beforeGets, getList, writeList, afterGets
 		return as
 	}
 
-	return vals(bgets), vals(cgets), vals(writes), vals(agets)
+	return vals(bgets), vals(cgets), append(vals(writes), nilkeys...), vals(agets)
 }
 
 // AsFunc creates and returns an "as function" that behaves as follows:

docstore/driver/util_test.go

@@ -91,6 +91,10 @@ func TestGroupActions(t *testing.T) {
 			},
 			want: [][]int{{0}, {1}, {2, 3}, {4}},
 		},
+		{
+			in:   []*Action{{Kind: Create}, {Kind: Create}, {Kind: Create}},
+			want: [][]int{nil, nil, {0, 1, 2}, nil},
+		},
 	} {
 		got := make([][]*Action, 4)
 		got[0], got[1], got[2], got[3] = GroupActions(test.in)
@@ -106,10 +110,11 @@ func TestGroupActions(t *testing.T) {
 				if a1.Kind != a2.Kind {
 					return a1.Kind < a2.Kind
 				}
-				return a1.Key.(int) < a2.Key.(int)
+				a1k, _ := a1.Key.(int)
+				a2k, _ := a2.Key.(int)
+				return a1k < a2k
 			}))
 		if diff != "" {
-
 			t.Errorf("%v: %s", test.in, diff)
 		}
 	}