Add case-insensitive fallback for response header logging (#150)

* add case-insensitive fallback for response header logging

* formatting

* Update src/Logging.fs

Co-authored-by: Dag Brattli <[email protected]>

* Simplify header logging

---------

Co-authored-by: Dag Brattli <[email protected]>

Author: ozangoktan

.paket/Paket.Restore.targets

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="Current" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <ActiveDebugProfile>IIS Express</ActiveDebugProfile>
+  </PropertyGroup>
+</Project>

examples/github/GitHub.fsproj.user

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="Current" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <ActiveDebugProfile>IIS Express</ActiveDebugProfile>
+  </PropertyGroup>
+</Project>

examples/wikisearch/WikiSearch.fsproj.user

@@ -24,19 +24,23 @@ module Logging =
     let private replacer (_: Match) : string =
         $"{{{PlaceHolder.ResponseHeader}__{Interlocked.Increment(&placeholderCounter)}}}"
 
+    let private lowerCaseHeaders (headers: Map<string, seq<string>>) : Map<string, seq<string>> =
+        headers |> Seq.map (fun kv -> kv.Key.ToLowerInvariant(), kv.Value) |> Map.ofSeq
+
     let private getHeaderValue (headers: Map<string, seq<string>>) (key: string) : string =
-        match headers.TryGetValue(key) with
-        | true, v ->
-            match Seq.tryHead v with
-            | first -> if first.IsSome then first.Value else String.Empty
-        | false, _ -> String.Empty
+        headers
+        |> Map.tryFind key
+        |> Option.defaultValue Seq.empty
+        |> Seq.tryHead
+        |> Option.defaultValue String.Empty
 
     let private log' logLevel ctx content =
         match ctx.Request.Logger with
         | Some logger ->
             let format = ctx.Request.LogFormat
             let request = ctx.Request
             let matches = reqex.Matches format
+            let lowerCaseHeaders = lazy (lowerCaseHeaders ctx.Response.Headers)
 
             // Create an array with values in the same order as in the format string. Important to be lazy and not
             // stringify any values here. Only pass references to the objects themselves so the logger can stringify
@@ -56,7 +60,7 @@ module Logging =
                     | PlaceHolder.ResponseHeader ->
                         // GroupCollection returns empty string values for indexes beyond what was captured, therefore
                         // we don't cause an exception here if the optional second group was not captured
-                        getHeaderValue ctx.Response.Headers match'.Groups[3].Value :> _
+                        getHeaderValue lowerCaseHeaders.Value (match'.Groups[3].Value.ToLowerInvariant()) :> _
                     | key ->
                         // Look for the key in the extra info. This also enables custom HTTP handlers to add custom
                         // placeholders to the format string.

src/Logging.fs

@@ -132,6 +132,7 @@ let ``Get with logging is OK`` () =
                    "Message"
                    "ResponseHeader[missing-key]"
                    "ResponseHeader[X-Request-ID]"
+                   "ResponseHeader[x-request-id]"
                    "ResponseHeader"
                    "ResponseHeader["
                    "ResponseHeader]"
@@ -163,7 +164,13 @@ let ``Get with logging is OK`` () =
         // Assert
         test <@ logger.Output.Contains "42" @>
         test <@ logger.Output.Contains "http://test.org" @>
-        test <@ logger.Output.Contains $"test-value\n← {msg}\n← \n← test-request-id\n← \n← \n← \n← \n← end" @>
+
+        test
+            <@
+                logger.Output.Contains
+                    $"test-value\n← {msg}\n← \n← test-request-id\n← test-request-id\n← \n← \n← \n← \n← end"
+            @>
+
         test <@ logger.Output.Contains "not-included-in-log" = false @>
         test <@ Result.isOk result @>
         test <@ metrics.Retries = 0L @>
@@ -204,6 +211,7 @@ let ``Post with logging is OK`` () =
                    "Message"
                    "ResponseHeader[missing-key]"
                    "ResponseHeader[X-Request-ID]"
+                   "ResponseHeader[x-request-id]"
                    "ResponseHeader"
                    "ResponseHeader["
                    "ResponseHeader]"
@@ -230,7 +238,13 @@ let ``Post with logging is OK`` () =
         test <@ logger.Output.Contains json @>
         test <@ logger.Output.Contains msg @>
         test <@ logger.Output.Contains "http://testing.org" @>
-        test <@ logger.Output.Contains $"test-value\n← {msg}\n← \n← test-request-id\n← \n← \n← \n← \n← end" @>
+
+        test
+            <@
+                logger.Output.Contains
+                    $"test-value\n← {msg}\n← \n← test-request-id\n← test-request-id\n← \n← \n← \n← \n← end"
+            @>
+
         test <@ logger.Output.Contains "not-included-in-log" = false @>
         test <@ Result.isOk result @>
         test <@ retries' = 1 @>

test/Fetch.fs

@@ -1 +1 @@
-6.0.1
+6.0.2