Add support for multiple uids in uid_in function

[all-seeing-code]

Currently uid_in functions checks membership of only one uid across a given predicate edge. This PR will extend the support of membership checks to multiple uids in a single query fragment. Particularly we can run queries like this which checks for the presense of two uids (0x4e472a and 0x4e472b):

q(func: eq(name, "Jane Doe") ){
                name
                friend @filter( uid_in(memberOf, [0x4e472a, 0x4e472b]) ) {
                    name
                }
 }

Fixes DGRAPH-1292

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This change is 

[pawanrawal]

Please add some tests similar to others that we have in the query package to make sure this works as expected.

Reviewed 2 of 2 files at r1.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @anurags92, @manishrjain, and @MichelDiz)

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worker/task.go, line 1831 at r1 (raw file):

				return nil, err
			}
			fc.uidsPresent = append(fc.uidsPresent, uidParsed)

This list probably needs to be sorted before interesting. See if your tests pass with the code as it is.

[MichelDiz]

Reviewed 4 of 4 files at r2.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @anurags92 and @manishrjain)

[all-seeing-code]

Added testing in parser and query packages

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @manishrjain and @pawanrawal)

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worker/task.go, line 1831 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

This list probably needs to be sorted before interesting. See if your tests pass with the code as it is.

Done.

[pawanrawal]

Mostly looks good, just needs some small changes.

Reviewed 4 of 4 files at r2.
Reviewable status: all files reviewed, 4 unresolved discussions (waiting on @anurags92 and @manishrjain)

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gql/parser_test.go, line 4903 at r2 (raw file):

			}
		}
		require.True(t, found, "vars not matched: %v", tc.vars)

Shouldn't this found be checked for each variable? That is it should be reset for each variable and checked in the loop above?

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query/query1_test.go, line 1044 at r2 (raw file):

	query := `
	{
		me(func: UID(1, 23, 24)) @filter(uid_in(school, 5000, 5001)) {

Lets add a couple of tests (one at root and one as a child) where the input to uid_in is not already sorted.

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query/query1_test.go, line 1049 at r2 (raw file):

	}`
	js := processQueryNoErr(t, query)
	require.JSONEq(t, `{"data": {"me":[{"name":"Michonne"},{"name":"Rick Grimes"},{"name":"Glenn Rhee"}]}}`, js)

Can you also add a starting node for which the uid_in filter fails? Right now it seems to pass for all 1, 23 and 24.

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query/query1_test.go, line 1083 at r2 (raw file):

	{
		me(func: uid(1, 23, 24 )) {
			friend @filter(uid_in(school, [5000, 5001])) {

We don't need to have separate cases for [5000, 5001] and 5000, 5001 since they are just different syntax for the same query. If anything, we can add those tests in gql/parser.go to verify they have the same args.

[all-seeing-code]

Reviewable status: 2 of 4 files reviewed, 4 unresolved discussions (waiting on @manishrjain, @MichelDiz, and @pawanrawal)

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gql/parser_test.go, line 4903 at r2 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

Shouldn't this found be checked for each variable? That is it should be reset for each variable and checked in the loop above?

Yes, nice catch. I have updated that in another function from where I copied this.

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query/query1_test.go, line 1044 at r2 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

Lets add a couple of tests (one at root and one as a child) where the input to uid_in is not already sorted.

Done.

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query/query1_test.go, line 1049 at r2 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

Can you also add a starting node for which the uid_in filter fails? Right now it seems to pass for all 1, 23 and 24.

Done.

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query/query1_test.go, line 1083 at r2 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

We don't need to have separate cases for [5000, 5001] and 5000, 5001 since they are just different syntax for the same query. If anything, we can add those tests in gql/parser.go to verify they have the same args.

Done.

[pawanrawal]

Reviewed 3 of 3 files at r3.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @anurags92 and @manishrjain)

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gql/parser_test.go, line 4905 at r3 (raw file):

			}
		}
		require.True(t, found, "vars not matched: %v", tc.vars)

This require.True should be in the loop above which goes over tc.vars.

[all-seeing-code]

Reviewable status: 2 of 4 files reviewed, 1 unresolved discussion (waiting on @manishrjain and @pawanrawal)

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gql/parser_test.go, line 4905 at r3 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

This require.True should be in the loop above which goes over tc.vars.

Done.

[manishrjain]

Got a couple of comments. Good to go!

Reviewable status: 2 of 4 files reviewed, 3 unresolved discussions (waiting on @anurags92 and @pawanrawal)

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query/query1_test.go, line 1049 at r4 (raw file):

	}`
	js := processQueryNoErr(t, query)
	require.JSONEq(t, `{"data": {"me":[{"name":"Michonne"},{"name":"Rick Grimes"},{"name":"Glenn Rhee"}]}}`, js)

I'd check if other lines in this file are violating the 100 char limit.

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worker/task.go, line 1835 at r4 (raw file):

			fc.uidsPresent = append(fc.uidsPresent, uidParsed)
		}
		sort.Slice(fc.uidsPresent, func(i, j int) bool { return fc.uidsPresent[i] < fc.uidsPresent[j] })

100 chars.

[all-seeing-code]

Reviewable status: 2 of 4 files reviewed, 3 unresolved discussions (waiting on @anurags92, @manishrjain, and @pawanrawal)

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query/query1_test.go, line 1049 at r4 (raw file):

Previously, manishrjain (Manish R Jain) wrote…

I'd check if other lines in this file are violating the 100 char limit.

Yes, a lot of tests are violating the 100 char limit mainly because the expected JSON strings are kept in one single line.