clock: Add timezone to all parsed dates

Previously the dates without timezone were assumed to use UTC when being
converted to unix time, but the datatype maintained the lack of timezone when
being printed. This means that the problematic timezoneless timestamps were
kept and could be produced by the hosts.

Since the dates are assumed to be UTC, add the timezone when they are parsed
for the first time. Now their timezone is displayed at all times.

The output of Localtime is kept without a timezone because clients are not
prepared to accept arbitrary timezones in dates. (Both the SDK and XO(Lite))

Signed-off-by: Pau Ruiz Safont <pau.ruizsafont@cloud.com>

Author: psafont

ocaml/libs/clock/date.ml

@@ -56,8 +56,8 @@ let best_effort_iso8601_to_rfc3339 x =
   in
   match tz with
   | None | Some "" ->
-      (* the caller didn't specify a tz, use the Unqualified Local Time *)
-      Printf.sprintf "%s-00:00" x
+      (* the caller didn't specify a tz, assume Coordinatel Universal Time *)
+      Printf.sprintf "%sZ" x
   | Some _ ->
       x
 

ocaml/libs/clock/test_date.ml

@@ -10,6 +10,28 @@ let dash_time_str = "2020-04-07T08:28:32Z"
 
 let no_dash_utc_time_str = "20200407T08:28:32Z"
 
+let best_effort_iso8601_to_rfc3339 x =
+  let x =
+    try
+      Scanf.sscanf x "%04d%02d%02dT%s" (fun y mon d rest ->
+          Printf.sprintf "%04d-%02d-%02dT%s" y mon d rest
+      )
+    with _ -> x
+  in
+  let tz =
+    try
+      Scanf.sscanf x "%04d-%02d-%02dT%02d:%02d:%02d%s" (fun _ _ _ _ _ _ tz ->
+          Some tz
+      )
+    with _ -> None
+  in
+  match tz with
+  | None | Some "" ->
+      (* the caller didn't specify a tz, use the Unqualified Local Time *)
+      Printf.sprintf "%s-00:00" x
+  | Some _ ->
+      x
+
 let tests =
   let test_of_unix_time_invertible () =
     let non_int_time = 1586245987.70200706 in
@@ -55,6 +77,21 @@ let tests =
     check_string "to_rfc3339 is backwards compatible" no_dash_utc_time_str
       (dash_time_str |> of_iso8601 |> to_rfc3339)
   in
+  let test_localtime () =
+    let time = localtime () in
+    match
+      time
+      |> to_rfc3339
+      |> best_effort_iso8601_to_rfc3339
+      |> Ptime.of_rfc3339
+      |> Ptime.rfc3339_error_to_msg
+    with
+    | Ok (_, tz, _) ->
+        Alcotest.(check @@ option int)
+          "localtime generates a timestamp without timezone" None tz
+    | Error (`Msg msg) ->
+        Alcotest.failf "Unexpected error: %s" msg
+  in
   let test_localtime_string () =
     let[@warning "-8"] (Ok (t, _, _)) =
       Ptime.of_rfc3339 "2020-04-07T09:01:28Z"
@@ -86,17 +123,19 @@ let tests =
       (String.contains localtime_string 'Z')
   in
   let test_xsi894 () =
+    let canonical = "20201210T17:19:20Z" in
     let missing_tz_no_dash = "20201210T17:19:20" in
     let missing_tz_dash = "2020-12-10T17:19:20" in
-    check_string "can process missing tz no dash" missing_tz_no_dash
+    check_string
+      "Timestamp without timezones nor dashes is accepted, gets converted to \
+       UTC"
+      canonical
       (missing_tz_no_dash |> of_iso8601 |> to_rfc3339) ;
-    check_string "can process missing tz with dashes, but return without dashes"
-      missing_tz_no_dash
-      (missing_tz_dash |> of_iso8601 |> to_rfc3339) ;
-    let localtime' = localtime () in
-    check_string "to_rfc3339 inverts of_iso8601 for localtime"
-      (localtime' |> to_rfc3339)
-      (localtime' |> to_rfc3339 |> of_iso8601 |> to_rfc3339)
+    check_string
+      "Timestamp without timezones, and dashes is accepted, gets converted to \
+       UTC"
+      canonical
+      (missing_tz_dash |> of_iso8601 |> to_rfc3339)
   in
   let test_email_date (unix_timestamp, expected) =
     let formatted = of_unix_time unix_timestamp |> to_rfc822 in
@@ -135,9 +174,10 @@ let tests =
     , `Quick
     , test_to_rfc3339_backwards_compatibility
     )
+  ; ("localtime is printed without timezone", `Quick, test_localtime)
   ; ("test_localtime_string", `Quick, test_localtime_string)
   ; ("test_ca342171", `Quick, test_ca342171)
-  ; ("test_xsi894", `Quick, test_xsi894)
+  ; ("Parsing datetimes without timezones", `Quick, test_xsi894)
   ; ( "Date w/o timezone to POSIX time conversion"
     , `Quick
     , test_no_timezone_to_unix