public async Task TakeLast()
{
// arrange
var list = new List <string> {
"a", "b", "c", "d", "e", "f", "g",
};
var pagingDetails = new PagingDetails
{
Last = 2
};
var connectionFactory = new QueryableConnectionResolver <string>(
list.AsQueryable(), pagingDetails);
// act
var connection = await connectionFactory.ResolveAsync(
CancellationToken.None);
// assert
Assert.Collection(connection.Edges,
t =>
{
Assert.Equal("f", t.Node);
Assert.Equal(5, GetPositionFromCursor(t.Cursor));
},
t =>
{
Assert.Equal("g", t.Node);
Assert.Equal(6, GetPositionFromCursor(t.Cursor));
});
}
public async Task HasPrevious_True()
{
// arrange
var list = new List <string> {
"a", "b", "c", "d", "e", "f", "g",
};
var connectionFactory = new QueryableConnectionResolver <string>(
list.AsQueryable(), new PagingDetails {
First = 1
});
var connection = await connectionFactory.ResolveAsync(
CancellationToken.None);
var pagingDetails = new PagingDetails
{
After = connection.PageInfo.StartCursor,
First = 2
};
connectionFactory = new QueryableConnectionResolver <string>(
list.AsQueryable(), pagingDetails);
// act
connection = await connectionFactory.ResolveAsync(
CancellationToken.None);
// assert
Assert.True(connection.PageInfo.HasPreviousPage);
}
private static QueryablePagingDetails DeserializePagingDetails(
PagingDetails pagingDetails)
{
Dictionary <string, object> afterProperties =
DeserializeCursor(pagingDetails.After);
Dictionary <string, object> beforeProperties =
DeserializeCursor(pagingDetails.Before);
return(new QueryablePagingDetails
{
After = GetPositionFromCurser(afterProperties),
Before = GetPositionFromCurser(beforeProperties),
TotalCount = GetPositionFromCurser(afterProperties)
?? GetPositionFromCurser(beforeProperties),
First = pagingDetails.First,
Last = pagingDetails.Last
});
}
public async Task HasPrevious_False()
{
// arrange
var list = new List <string> {
"a", "b", "c", "d", "e", "f", "g",
};
var pagingDetails = new PagingDetails();
var connectionFactory = new QueryableConnectionResolver <string>(
list.AsQueryable(), pagingDetails);
// act
var connection = await connectionFactory.ResolveAsync(
CancellationToken.None);
// assert
Assert.False(connection.PageInfo.HasPreviousPage);
}
public QueryableConnectionResolver(
IQueryable <T> source,
PagingDetails pagingDetails)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
if (pagingDetails == null)
{
throw new ArgumentNullException(nameof(pagingDetails));
}
_source = source;
_pageDetails = DeserializePagingDetails(pagingDetails);
_properties = pagingDetails.Properties
?? new Dictionary <string, object>();
}
public async Task TakeFirstAfter()
{
// arrange
var list = new List <string> {
"a", "b", "c", "d", "e", "f", "g",
};
var connectionFactory = new QueryableConnectionResolver <string>(
list.AsQueryable(), new PagingDetails {
First = 1
});
var connection = await connectionFactory.ResolveAsync(
CancellationToken.None);
var pagingDetails = new PagingDetails
{
After = connection.PageInfo.StartCursor,
First = 2
};
connectionFactory = new QueryableConnectionResolver <string>(
list.AsQueryable(), pagingDetails);
// act
connection = await connectionFactory.ResolveAsync(
CancellationToken.None);
// assert
Assert.Collection(connection.Edges,
t =>
{
Assert.Equal("b", t.Node);
Assert.Equal(1, GetPositionFromCursor(t.Cursor));
},
t =>
{
Assert.Equal("c", t.Node);
Assert.Equal(2, GetPositionFromCursor(t.Cursor));
});
}
public async Task InvokeAsync(IMiddlewareContext context)
{
await _next(context);
var pagingDetails = new PagingDetails
{
First = context.Argument <int?>("first"),
After = context.Argument <string>("after"),
Last = context.Argument <int?>("last"),
Before = context.Argument <string>("before"),
};
IQueryable <T> source = null;
if (context.Result is PageableData <T> p)
{
source = p.Source;
pagingDetails.Properties = p.Properties;
}
if (context.Result is IQueryable <T> q)
{
source = q;
}
if (context.Result is IEnumerable <T> e)
{
source = e.AsQueryable();
}
if (source != null)
{
var connectionResolver = _createConnectionResolver(
source, pagingDetails);
context.Result = await connectionResolver.ResolveAsync(
context.RequestAborted);
}
}
private static IConnectionResolver CreateConnectionResolver(
IQueryable <T> source, PagingDetails pagingDetails)
{
return(new QueryableConnectionResolver <T>(
source, pagingDetails));
}