feat(GraphQL): add support for between filter in GraphQL

[minhaj-shakeel]

Fixes GRAPHQL-667.

This PR extend support for between filter in GraphQL. This filter can be used for all scalars when indexed in a type (exact index for String). For the given type

type Student{
   age: Int @search
   name: String @search(by: [exact])
}

between filter can be used both on the age and name field. for eg:

queryStudent(filter: {age: {between: {min: 10, max: 20}}}){
    age
    name
}

and

queryStudent(filter: {name: {between: {min: "abc", max: "def"}}}){
    age
    name
}

are both valid queries.

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This change is 

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[pawanrawal]

Currently between only works at the root and not inside filter, so it won't work well with GraphQL. We are keeping this on hold until between works properly at the root and in filters and then we'll do this.

[pawanrawal]

It's looking great but some CI tests are failing. Can you fix those?

Reviewed 49 of 49 files at r2.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @MichaelJCompton and @minhaj-shakeel)

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graphql/e2e/common/query.go, line 449 at r2 (raw file):

	err := json.Unmarshal([]byte(gqlResponse.Data), &result)
	require.NoError(t, err)
	require.Equal(t, 3, len(result.QueryPost))

Can we compare the result as well?

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graphql/resolve/query_rewriter.go, line 1097 at r2 (raw file):

					// 	between(numLikes,10,20). Order of arguments (min,max) is neccessary or
					// it will return empty
					vals := val.(map[string]interface{})

Is this safe to do? We should check the second argument and return an error if this conversion is not possible.

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graphql/resolve/query_rewriter.go, line 1098 at r2 (raw file):

					// it will return empty
					vals := val.(map[string]interface{})
					args = append(args, gql.Arg{Value: maybeQuoteArg(fn, vals["min"])})

You can do this in one statement.

args = append(args, arg1 , arg2)

[minhaj-shakeel]

Reviewable status: 46 of 49 files reviewed, 3 unresolved discussions (waiting on @MichaelJCompton and @pawanrawal)

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graphql/e2e/common/query.go, line 449 at r2 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

Can we compare the result as well?

Done.

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graphql/resolve/query_rewriter.go, line 1097 at r2 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

Is this safe to do? We should check the second argument and return an error if this conversion is not possible.

Yeah, it is safe as it will be get caught up in the validation stage.

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graphql/resolve/query_rewriter.go, line 1098 at r2 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

You can do this in one statement.

args = append(args, arg1 , arg2)

Done.