refactor: Remove pipeline abstraction

src/HttpHandler/Builder.fs → src/Builder.fs

@@ -3,7 +3,6 @@
 
 namespace Oryx
 
-open Oryx.Pipeline
 
 type RequestBuilder() =
     member _.Zero() : HttpHandler<unit> = httpRequest
@@ -12,14 +11,14 @@ type RequestBuilder() =
     member _.Return(content: 'TResult) : HttpHandler<'TResult> = singleton content
     member _.ReturnFrom(req: HttpHandler<'TResult>) : HttpHandler<'TResult> = req
     member _.Delay(fn) = fn ()
-    member _.Combine(source, other) = source |> Core.bind (fun _ -> other)
+    member _.Combine(source, other) = source |> bind (fun _ -> other)
 
     member _.For(source: 'TSource seq, func: 'TSource -> HttpHandler<'TResult>) : HttpHandler<'TResult list> =
         source |> Seq.map func |> sequential
 
     /// Binds value of 'TValue for let! All handlers runs in same context within the builder.
     member _.Bind(source: HttpHandler<'TSource>, fn: 'TSource -> HttpHandler<'TResult>) : HttpHandler<'TResult> =
-        source |> Core.bind fn
+        source |> bind fn
 
 [<AutoOpen>]
 module Builder =

src/Core.fs

@@ -0,0 +1,19 @@
+// Copyright 2020 Cognite AS
+// SPDX-License-Identifier: Apache-2.0
+
+namespace Oryx
+
+open System.Threading.Tasks
+
+type IHttpNext<'TSource> =
+    abstract member OnSuccessAsync: ctx: HttpContext * content: 'TSource -> Task<unit>
+    abstract member OnErrorAsync: ctx: HttpContext * error: exn -> Task<unit>
+    abstract member OnCancelAsync: ctx: HttpContext -> Task<unit>
+
+type HttpHandler<'TResult> = IHttpNext<'TResult> -> Task<unit>
+
+exception HttpException of (HttpContext * exn) with
+    override this.ToString() =
+        match this :> exn with
+        | HttpException(_, err) -> err.ToString()
+        | _ -> failwith "This should not never happen."

src/Pipeline/Error.fs → src/Error.fs

@@ -1,20 +1,19 @@
 // Copyright 2020 Cognite AS
 // SPDX-License-Identifier: Apache-2.0
-
-namespace Oryx.Pipeline
+namespace Oryx
 
 open System
 
 open FSharp.Control.TaskBuilder
 open Oryx
 
 module Error =
-    /// Handler for protecting the pipeline from exceptions and protocol violations.
-    let protect<'TContext, 'TSource> (source: Pipeline<'TContext, 'TSource>) : Pipeline<'TContext, 'TSource> =
+    /// Handler for protecting the HttpHandler from exceptions and protocol violations.
+    let protect<'TSource> (source: HttpHandler<'TSource>) : HttpHandler<'TSource> =
         fun next ->
             let mutable stopped = false
 
-            { new IAsyncNext<'TContext, 'TSource> with
+            { new IHttpNext<'TSource> with
                 member _.OnSuccessAsync(ctx, content) =
                     task {
                         match stopped with
@@ -47,12 +46,12 @@ module Error =
             |> source
 
     /// Handler for catching errors and then delegating to the error handler on what to do.
-    let catch<'TContext, 'TSource>
-        (errorHandler: 'TContext -> exn -> Pipeline<'TContext, 'TSource>)
-        (source: Pipeline<'TContext, 'TSource>)
-        : Pipeline<'TContext, 'TSource> =
+    let catch<'TSource>
+        (errorHandler: HttpContext -> exn -> HttpHandler<'TSource>)
+        (source: HttpHandler<'TSource>)
+        : HttpHandler<'TSource> =
         fun next ->
-            { new IAsyncNext<'TContext, 'TSource> with
+            { new IHttpNext<'TSource> with
                 member _.OnSuccessAsync(ctx, content) =
                     task {
                         try
@@ -66,7 +65,6 @@ module Error =
                         match err with
                         | PanicException error -> return! next.OnErrorAsync(ctx, error)
                         | _ -> do! (errorHandler ctx err) next
-
                     }
 
                 member _.OnCancelAsync(ctx) = next.OnCancelAsync(ctx) }
@@ -79,22 +77,22 @@ module Error =
         | Error
         | Panic
 
-    /// Choose from a list of pipelines to use. The first middleware that succeeds will be used. Handlers will be
+    /// Choose from a list of HttpHandlers to use. The first middleware that succeeds will be used. Handlers will be
     /// tried until one does not produce any error, or a `PanicException`.
-    let choose<'TContext, 'TSource, 'TResult>
-        (handlers: (Pipeline<'TContext, 'TSource> -> Pipeline<'TContext, 'TResult>) list)
-        (source: Pipeline<'TContext, 'TSource>)
-        : Pipeline<'TContext, 'TResult> =
+    let choose<'TSource, 'TResult>
+        (handlers: (HttpHandler<'TSource> -> HttpHandler<'TResult>) list)
+        (source: HttpHandler<'TSource>)
+        : HttpHandler<'TResult> =
         fun next ->
             let exns: ResizeArray<exn> = ResizeArray()
 
-            { new IAsyncNext<'TContext, 'TSource> with
+            { new IHttpNext<'TSource> with
                 member _.OnSuccessAsync(ctx, content) =
                     let mutable state = ChooseState.Error
 
                     task {
                         let obv =
-                            { new IAsyncNext<'TContext, 'TResult> with
+                            { new IHttpNext<'TResult> with
                                 member _.OnSuccessAsync(ctx, content) =
                                     task {
                                         exns.Clear() // Clear to avoid buildup of exceptions in streaming scenarios.
@@ -106,10 +104,10 @@ module Error =
                                 member _.OnErrorAsync(_, error) =
                                     task {
                                         match error, state with
-                                        | PanicException(_), st when st <> ChooseState.Panic ->
+                                        | PanicException _, st when st <> ChooseState.Panic ->
                                             state <- ChooseState.Panic
                                             return! next.OnErrorAsync(ctx, error)
-                                        | SkipException(_), st when st = ChooseState.NoError ->
+                                        | SkipException _, st when st = ChooseState.NoError ->
                                             // Flag error, but do not record skips.
                                             state <- ChooseState.Error
                                         | _, ChooseState.Panic ->
@@ -122,7 +120,7 @@ module Error =
 
                                 member _.OnCancelAsync(ctx) = next.OnCancelAsync(ctx) }
 
-                        /// Proces handlers until `NoError` or `Panic`.
+                        // Process handlers until `NoError` or `Panic`.
                         for handler in handlers do
                             if state = ChooseState.Error then
                                 state <- ChooseState.NoError
@@ -134,9 +132,9 @@ module Error =
                             ()
                         | ChooseState.Error, exns when exns.Count > 1 ->
                             return! next.OnErrorAsync(ctx, AggregateException(exns))
-                        | ChooseState.Error, exns when exns.Count = 1 -> return! next.OnErrorAsync(ctx, exns.[0])
+                        | ChooseState.Error, exns when exns.Count = 1 -> return! next.OnErrorAsync(ctx, exns[0])
                         | ChooseState.Error, _ ->
-                            return! next.OnErrorAsync(ctx, SkipException "Choose: No hander matched")
+                            return! next.OnErrorAsync(ctx, SkipException "Choose: No handler matched")
                         | ChooseState.NoError, _ -> ()
                     }
 
@@ -151,25 +149,19 @@ module Error =
             |> source
 
     /// Error handler for forcing error. Use with e.g `req` computational expression if you need to "return" an error.
-    let fail<'TContext, 'TSource, 'TResult>
-        (err: Exception)
-        (source: Pipeline<'TContext, 'TSource>)
-        : Pipeline<'TContext, 'TResult> =
+    let fail<'TSource, 'TResult> (err: Exception) (source: HttpHandler<'TSource>) : HttpHandler<'TResult> =
         fun next ->
-            { new IAsyncNext<'TContext, 'TSource> with
+            { new IHttpNext<'TSource> with
                 member _.OnSuccessAsync(ctx, content) = next.OnErrorAsync(ctx, err)
                 member _.OnErrorAsync(ctx, exn) = next.OnErrorAsync(ctx, exn)
                 member _.OnCancelAsync(ctx) = next.OnCancelAsync(ctx) }
             |> source
 
     /// Error handler for forcing a panic error. Use with e.g `req` computational expression if you need break out of
     /// the any error handling e.g `choose` or `catch`•.
-    let panic<'TContext, 'TSource, 'TResult>
-        (err: Exception)
-        (source: Pipeline<'TContext, 'TSource>)
-        : Pipeline<'TContext, 'TResult> =
+    let panic<'TSource, 'TResult> (err: Exception) (source: HttpHandler<'TSource>) : HttpHandler<'TResult> =
         fun next ->
-            { new IAsyncNext<'TContext, 'TSource> with
+            { new IHttpNext<'TSource> with
                 member _.OnSuccessAsync(ctx, content) =
                     next.OnErrorAsync(ctx, PanicException(err))
 

src/HttpHandler/Fetch.fs → src/Fetch.fs

@@ -11,7 +11,6 @@ open System.Net.Http.Headers
 open System.Web
 
 open FSharp.Control.TaskBuilder
-open Oryx.Pipeline
 
 [<AutoOpen>]
 module Fetch =
@@ -101,7 +100,6 @@ module Fetch =
                                     response.Content
                                 )
 
-
                             response.Dispose()
                             return result
                         with ex when not (ex :? HttpException) ->