Exporting of types with back edges

[Kingloko]

What version of Dgraph are you using?

v1.2.1

Have you tried reproducing the issue with the latest release?

yes

What is the hardware spec (RAM, OS)?

Ubuntu, 32gb, running inside the docker

Steps to reproduce the issue (command/config used to run Dgraph).

in shell:

dgraph zero &
dgraph  alpha &

in python

import pydgraph

client_stub = pydgraph.DgraphClientStub('localhost:9080')
client = pydgraph.DgraphClient(client_stub)
schema = """
back_edge: [uid] @reverse .
type WillCrash {
   back_edge
   <~back_edge>
}
"""
client.alter(pydgraph.Operation(schema=schema))

back in shell

curl localhost:8080/admin/export?format=json
curl localhost:8080/admin/shutdown
--cd into export dir 
dgraph bulk -f g01.json.gz -s g01.schema.gz 

Expected behaviour and actual result.

I'd expect it to successfully load via zero but I get the following error:

2020/02/26 20:28:32 while lexing <back_edge>:[uid] @reverse . 
<dgraph.type>:[string] @index(exact) . 
type WillCrash {
	back_edge
	~back_edge
}
 at line 5 column 1: Invalid schema. Unexpected ~

fwiw: If I change WillCrash to include "<~back_edge>" instead of the exported ~back_edge I have no issues

[Kingloko]

Not sure if this is helpful or not - but I figured I'd add it

root@e7c29139044b:/dgraph/export/dgraph.r5.u0226.2027# gunzip g01.schema.gz 
root@e7c29139044b:/dgraph/export/dgraph.r5.u0226.2027# vim g01.schema 
bash: vim: command not found
root@e7c29139044b:/dgraph/export/dgraph.r5.u0226.2027# cat g01.schema 
<back_edge>:[uid] @reverse . 
<dgraph.type>:[string] @index(exact) . 
type WillCrash {
	back_edge
	~back_edge
}

[martinmr]

Yeah, seems like a bug. Reverse predicate names require the <~pred> notation to be properly parsed. But it doesn't look like the export tool is taking care of that. I'll send a bug fix soon.

[Kingloko]

Thanks @martinmr!