Support weird cookie trick

src/Tie/Codegen/Operation.hs

@@ -93,7 +93,7 @@ codegenOperations resolver operations = do
                     )
               )
 
-      inlineablePragma = 
+      inlineablePragma =
         "{-#" <+> "INLINABLE" <+> "application" <+> "#-}"
 
   pure (dataApiDecl <> PP.line <> PP.line <> apiDecl <> PP.line <> inlineablePragma)

src/Tie/Name.hs

@@ -154,9 +154,14 @@ toFieldName :: Name -> PP.Doc ann
 toFieldName =
   PP.pretty . Text.pack . escapeKeyword . lowerFirstLetter . toCamelCase . Text.unpack . unName
 
+-- | Returns the name as written, should be used within quotes only.
 toParamName :: Name -> PP.Doc ann
 toParamName =
-  PP.pretty . unName
+  PP.pretty . filterNUL . unName
+  where
+    -- Filter away '\0' to support the weird cookie trick
+    -- (see test/golden/weird-cookie-trick.yaml)
+    filterNUL = Text.filter (/= '\0')
 
 toParamBinder :: Name -> PP.Doc ann
 toParamBinder =
@@ -262,12 +267,12 @@ escapeKeyword input = haskelify $ case input of
   _ -> input
 
 haskelify :: String -> String
-haskelify xs =
-  [ case x of
-      '-' -> '_'
-      _ -> x
-    | x <- xs
-  ]
+haskelify = concatMap escape
+  where
+    escape c = case c of
+      '-' -> "_"
+      '\0' -> "NUL"
+      _ -> [c]
 
 toCamelCase :: String -> String
 toCamelCase input =

test/golden/weird-cookie-trick.yaml

@@ -0,0 +1,32 @@
+openapi: "3.0.0"
+info:
+  version: 1.0.0
+  title: Scarf
+  license:
+    name: AllRightsReserved
+servers:
+  - url: https://scarf.sh/api/v1
+paths:
+  /test:
+    get:
+      summary: test
+      operationId: test
+      responses:
+        '200':
+          description: Some response
+          content:
+            application/json: 
+              schema:
+                description: Undocumented
+          headers:
+            Set-Cookie:
+              description: Session cookie
+              schema:
+                type: string
+                example: SESSIONID=abcde12345; Path=/
+            "\0Set-Cookie":
+              description: CSRF token
+              schema:
+                type: string
+                example: CSRFTOKEN=fghijk678910; Path=/; HttpOnly
+components: {}