fix: add missing Content-Length to empty HTTP 201 responses

For when a preference other than return=representation is requested.

CHANGELOG.md

@@ -12,6 +12,7 @@ All notable changes to this project will be documented in this file. From versio
 
 - Fix regression where the `PGRST103` error response was truncated by @laurenceisla in #4455
   + Happened when an `offset` was greater than the rows requested and `Prefer: count=exact` was sent.
+- Fix not returning `Content-Length` on empty HTTP `201` responses by @laurenceisla in #4518
 
 ## Fixed
 

src/PostgREST/Response.hs

@@ -106,7 +106,6 @@ actionResponse (DbCrudResult MutateReadPlan{mrMutation=MutationCreate, mrMutateP
               )
         , Just . RangeQuery.contentRangeH 1 0 $
             if shouldCount preferCount then Just rsQueryTotal else Nothing
-        , Just $ contentLengthHeaderStrict rsBody
         , prefHeader ]
 
     isInsertIfGTZero i =
@@ -121,7 +120,7 @@ actionResponse (DbCrudResult MutateReadPlan{mrMutation=MutationCreate, mrMutateP
       Just HeadersOnly -> (headers, mempty)
       Nothing -> (headers, mempty)
 
-  (ovStatus, ovHeaders) <- overrideStatusHeaders rsGucStatus rsGucHeaders status headers'
+  (ovStatus, ovHeaders) <- overrideStatusHeaders rsGucStatus rsGucHeaders status $ contentLengthHeaderLazy bod:headers'
 
   Right $ PgrstResponse ovStatus ovHeaders bod
 

test/spec/Feature/Query/InsertSpec.hs

@@ -138,6 +138,7 @@ spec actualPgVersion = do
             , matchHeaders = [ matchHeaderAbsent hContentType
                              , "Location" <:> "/projects?id=eq.11"
                              , "Content-Range" <:> "*/*"
+                             , "Content-Length" <:> "0"
                              , "Preference-Applied" <:> "return=headers-only"]
             }
 
@@ -151,6 +152,7 @@ spec actualPgVersion = do
             , matchHeaders = [ matchHeaderAbsent hContentType
                              , "Location" <:> "/car_models?name=eq.Enzo&year=eq.2021"
                              , "Content-Range" <:> "*/*"
+                             , "Content-Length" <:> "0"
                              , "Preference-Applied" <:> "return=headers-only"]
             }
 
@@ -163,7 +165,8 @@ spec actualPgVersion = do
             ""
             { matchStatus  = 201
             , matchHeaders = [ matchHeaderAbsent hContentType
-                             , matchHeaderAbsent hLocation ]
+                             , matchHeaderAbsent hLocation
+                             , "Content-Length" <:> "0"]
             }
 
     context "from an html form" $
@@ -175,7 +178,8 @@ spec actualPgVersion = do
           `shouldRespondWith`
             ""
             { matchStatus = 201
-            , matchHeaders = [ matchHeaderAbsent hContentType ]
+            , matchHeaders = [ matchHeaderAbsent hContentType
+                             , "Content-Length" <:> "0"]
             }
 
     context "with no pk supplied" $ do
@@ -199,6 +203,7 @@ spec actualPgVersion = do
               ""
               { matchStatus  = 201
               , matchHeaders = [ matchHeaderAbsent hContentType
+                               , "Content-Length" <:> "0"
                                , "Location" <:> "/auto_incrementing_pk?id=eq.2"
                                , "Preference-Applied" <:> "return=headers-only"]
               }
@@ -741,6 +746,7 @@ spec actualPgVersion = do
           ""
           { matchStatus = 201
           , matchHeaders = [matchHeaderAbsent hContentType
+                           , "Content-Length" <:> "0"
                            , "Preference-Applied" <:> "return=minimal"]
           }
 
@@ -753,7 +759,8 @@ spec actualPgVersion = do
             ""
             { matchStatus  = 201
             , matchHeaders = [ matchHeaderAbsent hContentType
-                             , matchHeaderAbsent hLocation ]
+                             , matchHeaderAbsent hLocation
+                             , "Content-Length" <:> "0"]
             }
 
       it "returns a location header with pks from both tables" $
@@ -765,6 +772,7 @@ spec actualPgVersion = do
             , matchHeaders = [ matchHeaderAbsent hContentType
                              , "Location" <:> "/with_multiple_pks?pk1=eq.1&pk2=eq.2"
                              , "Content-Range" <:> "*/*"
+                             , "Content-Length" <:> "0"
                              , "Preference-Applied" <:> "return=headers-only"]
             }
 
@@ -778,6 +786,7 @@ spec actualPgVersion = do
             , matchHeaders = [ matchHeaderAbsent hContentType
                              , "Location" <:> "/compound_pk_view?k1=eq.1&k2=eq.test"
                              , "Content-Range" <:> "*/*"
+                             , "Content-Length" <:> "0"
                              , "Preference-Applied" <:> "return=headers-only"]
             }
 
@@ -790,6 +799,7 @@ spec actualPgVersion = do
             , matchHeaders = [ matchHeaderAbsent hContentType
                              , "Location" <:> "/test_null_pk_competitors_sponsors?id=eq.1&sponsor_id=is.null"
                              , "Content-Range" <:> "*/*"
+                             , "Content-Length" <:> "0"
                              , "Preference-Applied" <:> "return=headers-only"]
             }
 
@@ -807,6 +817,7 @@ spec actualPgVersion = do
             , matchHeaders = [ matchHeaderAbsent hContentType
                              , "Location" <:> "/datarep_todos?id=eq.5"
                              , "Content-Range" <:> "*/*"
+                             , "Content-Length" <:> "0"
                              , "Preference-Applied" <:> "return=headers-only"]
             }
 
@@ -862,6 +873,7 @@ spec actualPgVersion = do
             , matchHeaders = [ matchHeaderAbsent hContentType
                              , "Location" <:> "/datarep_todos_computed?id=eq.5"
                              , "Content-Range" <:> "*/*"
+                             , "Content-Length" <:> "0"
                              , "Preference-Applied" <:> "return=headers-only"]
             }
 

test/spec/Feature/RollbackSpec.hs

@@ -20,7 +20,9 @@ postItem =
     `shouldRespondWith`
       ""
       { matchStatus  = 201
-      , matchHeaders = [matchHeaderAbsent hContentType]  }
+      , matchHeaders = [ matchHeaderAbsent hContentType
+                       , "Content-Length" <:> "0" ]
+      }
 
 -- removes Items left over from POST, PUT, and PATCH
 deleteItems =