message_store.js: Add tests for erorrs/edge cases.
message_store.js: Add tests for erorrs/edge cases.

rht/zulip,vabs22/zulip,shubhamdhama/zulip,andersk/zulip,showell/zulip,kou/zulip,eeshangarg/zulip,punchagan/zulip,brockwhittaker/zulip,rishig/zulip,brainwane/zulip,synicalsyntax/zulip,verma-varsha/zulip,rishig/zulip,eeshangarg/zulip,shubhamdhama/zulip,punchagan/zulip,zulip/zulip,kou/zulip,jackrzhang/zulip,dhcrzf/zulip,showell/zulip,vabs22/zulip,verma-varsha/zulip,showell/zulip,zulip/zulip,timabbott/zulip,punchagan/zulip,timabbott/zulip,synicalsyntax/zulip,tommyip/zulip,dhcrzf/zulip,zulip/zulip,Galexrt/zulip,jackrzhang/zulip,brockwhittaker/zulip,andersk/zulip,hackerkid/zulip,jackrzhang/zulip,brainwane/zulip,Galexrt/zulip,brainwane/zulip,amanharitsh123/zulip,zulip/zulip,vaidap/zulip,eeshangarg/zulip,Galexrt/zulip,zulip/zulip,synicalsyntax/zulip,eeshangarg/zulip,synicalsyntax/zulip,dhcrzf/zulip,verma-varsha/zulip,tommyip/zulip,mahim97/zulip,rht/zulip,hackerkid/zulip,vabs22/zulip,vaidap/zulip,vaidap/zulip,kou/zulip,timabbott/zulip,kou/zulip,andersk/zulip,mahim97/zulip,synicalsyntax/zulip,brainwane/zulip,dhcrzf/zulip,punchagan/zulip,jrowan/zulip,amanharitsh123/zulip,eeshangarg/zulip,synicalsyntax/zulip,jrowan/zulip,tommyip/zulip,synicalsyntax/zulip,rht/zulip,shubhamdhama/zulip,hackerkid/zulip,jackrzhang/zulip,mahim97/zulip,shubhamdhama/zulip,brockwhittaker/zulip,brainwane/zulip,eeshangarg/zulip,jackrzhang/zulip,rishig/zulip,andersk/zulip,rishig/zulip,punchagan/zulip,showell/zulip,mahim97/zulip,mahim97/zulip,shubhamdhama/zulip,rishig/zulip,jrowan/zulip,rishig/zulip,amanharitsh123/zulip,jrowan/zulip,brockwhittaker/zulip,dhcrzf/zulip,showell/zulip,hackerkid/zulip,hackerkid/zulip,zulip/zulip,showell/zulip,kou/zulip,brockwhittaker/zulip,shubhamdhama/zulip,vaidap/zulip,andersk/zulip,dhcrzf/zulip,jrowan/zulip,vabs22/zulip,Galexrt/zulip,brainwane/zulip,showell/zulip,vabs22/zulip,verma-varsha/zulip,vaidap/zulip,rht/zulip,andersk/zulip,verma-varsha/zulip,Galexrt/zulip,kou/zulip,jackrzhang/zulip,punchagan/zulip,mahim97/zulip,andersk/zulip,timabbott/zulip,tommyip/zulip,jackrzhang/zulip,jrowan/zulip,hackerkid/zulip,vaidap/zulip,zulip/zulip,hackerkid/zulip,eeshangarg/zulip,tommyip/zulip,brainwane/zulip,shubhamdhama/zulip,verma-varsha/zulip,vabs22/zulip,amanharitsh123/zulip,rht/zulip,dhcrzf/zulip,rht/zulip,timabbott/zulip,Galexrt/zulip,tommyip/zulip,Galexrt/zulip,amanharitsh123/zulip,amanharitsh123/zulip,kou/zulip,tommyip/zulip,timabbott/zulip,rishig/zulip,brockwhittaker/zulip,punchagan/zulip,rht/zulip,timabbott/zulip