module CircularBufferTests open FsUnit.Xunit open Xunit open System open CircularBuffer [] let ``Reading empty buffer should fail`` () = let buffer1 = mkCircularBuffer 1 (fun () -> read buffer1 |> ignore) |> should throw typeof [] let ``Can read an item just written`` () = let buffer1 = mkCircularBuffer 1 let buffer2 = write 1 buffer1 let (val3, _) = read buffer2 val3 |> should equal 1 [] let ``Each item may only be read once`` () = let buffer1 = mkCircularBuffer 1 let buffer2 = write 1 buffer1 let (val3, buffer3) = read buffer2 val3 |> should equal 1 (fun () -> read buffer3 |> ignore) |> should throw typeof [] let ``Items are read in the order they are written`` () = let buffer1 = mkCircularBuffer 2 let buffer2 = write 1 buffer1 let buffer3 = write 2 buffer2 let (val4, buffer4) = read buffer3 val4 |> should equal 1 let (val5, _) = read buffer4 val5 |> should equal 2 [] let ``Full buffer can't be written to`` () = let buffer1 = mkCircularBuffer 1 let buffer2 = write 1 buffer1 (fun () -> write 2 buffer2 |> ignore) |> should throw typeof [] let ``A read frees up capacity for another write`` () = let buffer1 = mkCircularBuffer 1 let buffer2 = write 1 buffer1 let (val3, buffer3) = read buffer2 val3 |> should equal 1 let buffer4 = write 2 buffer3 let (val5, _) = read buffer4 val5 |> should equal 2 [] let ``Read position is maintained even across multiple writes`` () = let buffer1 = mkCircularBuffer 3 let buffer2 = write 1 buffer1 let buffer3 = write 2 buffer2 let (val4, buffer4) = read buffer3 val4 |> should equal 1 let buffer5 = write 3 buffer4 let (val6, buffer6) = read buffer5 val6 |> should equal 2 let (val7, _) = read buffer6 val7 |> should equal 3 [] let ``Items cleared out of buffer can't be read`` () = let buffer1 = mkCircularBuffer 1 let buffer2 = write 1 buffer1 let buffer3 = clear buffer2 (fun () -> read buffer3 |> ignore) |> should throw typeof [] let ``Clear frees up capacity for another write`` () = let buffer1 = mkCircularBuffer 1 let buffer2 = write 1 buffer1 let buffer3 = clear buffer2 let buffer4 = write 2 buffer3 let (val5, _) = read buffer4 val5 |> should equal 2 [] let ``Clear does nothing on empty buffer`` () = let buffer1 = mkCircularBuffer 1 let buffer2 = clear buffer1 let buffer3 = write 1 buffer2 let (val4, _) = read buffer3 val4 |> should equal 1 [] let ``Overwrite acts like write on non-full buffer`` () = let buffer1 = mkCircularBuffer 2 let buffer2 = write 1 buffer1 let buffer3 = forceWrite 2 buffer2 let (val4, buffer4) = read buffer3 val4 |> should equal 1 let (val5, _) = read buffer4 val5 |> should equal 2 [] let ``Overwrite replaces the oldest item on full buffer`` () = let buffer1 = mkCircularBuffer 2 let buffer2 = write 1 buffer1 let buffer3 = write 2 buffer2 let buffer4 = forceWrite 3 buffer3 let (val5, buffer5) = read buffer4 val5 |> should equal 2 let (val6, _) = read buffer5 val6 |> should equal 3 [] let ``Overwrite replaces the oldest item remaining in buffer following a read`` () = let buffer1 = mkCircularBuffer 3 let buffer2 = write 1 buffer1 let buffer3 = write 2 buffer2 let buffer4 = write 3 buffer3 let (val5, buffer5) = read buffer4 val5 |> should equal 1 let buffer6 = write 4 buffer5 let buffer7 = forceWrite 5 buffer6 let (val8, buffer8) = read buffer7 val8 |> should equal 3 let (val9, buffer9) = read buffer8 val9 |> should equal 4 let (val10, _) = read buffer9 val10 |> should equal 5 [] let ``Initial clear does not affect wrapping around`` () = let buffer1 = mkCircularBuffer 2 let buffer2 = clear buffer1 let buffer3 = write 1 buffer2 let buffer4 = write 2 buffer3 let buffer5 = forceWrite 3 buffer4 let buffer6 = forceWrite 4 buffer5 let (val7, buffer7) = read buffer6 val7 |> should equal 3 let (val8, buffer8) = read buffer7 val8 |> should equal 4 (fun () -> read buffer8 |> ignore) |> should throw typeof