CBU (Clave Bancaria Uniforme, Argentine bank account number)

lib/ar/cbu.ml

@@ -0,0 +1,41 @@
+open Tools
+
+exception Invalid_length
+exception Invalid_format
+exception Invalid_checksum
+
+let compact number = Utils.clean number " -" |> String.trim
+
+let calc_check_digit number =
+  let weights = [| 3; 1; 7; 9 |] in
+  let len = String.length number in
+  let rec sum i acc =
+    if i < len then
+      let w = weights.((len - 1 - i) mod 4) in
+      let n = int_of_char number.[i] - int_of_char '0' in
+      sum (i + 1) (acc + (w * n))
+    else acc
+  in
+  string_of_int ((10 - sum 0 0) mod 10)
+
+let validate number =
+  let number = compact number in
+  if String.length number <> 22 then raise Invalid_length
+  else if not (Utils.is_digits number) then raise Invalid_format
+  else if number.[7] <> (calc_check_digit (String.sub number 0 7)).[0] then
+    raise Invalid_checksum
+  else if
+    number.[String.length number - 1]
+    <> (calc_check_digit (String.sub number 8 (String.length number - 9))).[0]
+  then raise Invalid_checksum
+  else number
+
+let is_valid number =
+  try
+    ignore (validate number);
+    true
+  with Invalid_format | Invalid_length | Invalid_checksum -> false
+
+let format number =
+  let number = compact number in
+  String.sub number 0 8 ^ " " ^ String.sub number 8 14

lib/ar/cbu.mli

@@ -0,0 +1,40 @@
+(*
+CBU (Clave Bancaria Uniforme, Argentine bank account number).
+
+CBU it s a code of the Banks of Argentina to identify customer accounts. The
+number consists of 22 digits and consists of a 3 digit bank identifier,
+followed by a 4 digit branch identifier, a check digit, a 13 digit account
+identifier and another check digit.
+
+More information:
+
+* https://es.wikipedia.org/wiki/Clave_Bancaria_Uniforme
+*)
+
+exception Invalid_length
+(** Exception raised when the CBU number has an invalid length. *)
+
+exception Invalid_format
+(** Exception raised when the CBU number has an invalid format. *)
+
+exception Invalid_checksum
+(** Exception raised when the CBU number has an invalid checksum. *)
+
+val validate : string -> string
+(** Check if the number is a valid CBU. Returns the normalized number if valid.
+    @raise Invalid_length if the number length is not 22
+    @raise Invalid_format if the number contains non-digit characters
+    @raise Invalid_checksum if either check digit is invalid *)
+
+val is_valid : string -> bool
+(** Check if the number is a valid CBU. Returns true if valid, false otherwise. *)
+
+val format : string -> string
+(** Reformat the number to the standard presentation format with spaces. *)
+
+val compact : string -> string
+(** [compact number] removes spaces and dashes from the number. *)
+
+val calc_check_digit : string -> string
+(** [calc_check_digit number] calculates the check digit for the given number sequence
+    using the CBU algorithm. *)

lib/ar/dune

@@ -0,0 +1,4 @@
+(library
+ (name ar)
+ (public_name stdnum.ar)
+ (libraries stdnum.tools))

lib/tools/dune

@@ -1,3 +1,4 @@
 (library
  (name tools)
+ (public_name stdnum.tools)
  (libraries str))

test/ar/dune

@@ -0,0 +1,3 @@
+(test
+ (name test_cbu)
+ (libraries alcotest stdnum.tools stdnum.ar))

test/ar/test_cbu.ml

@@ -0,0 +1,146 @@
+open Ar.Cbu
+open Alcotest
+
+let test_valid_numbers () =
+  let numbers =
+    [
+      "0070999020000065706080"
+    ; "0110433630043313857683"
+    ; "0140339601630201381276"
+    ; "0140023601506802625874"
+    ; "0440064640000142941092"
+    ; "0720146820000001062340"
+    ; "0720168020000001183236"
+    ; "0720380888000035533968"
+    ; "0070034420000002310035"
+    ; "0070085620000002598406"
+    ; "0070089420000002991793"
+    ; "0070090020000004146504"
+    ; "0070109530004141775453"
+    ; "0070114920000004100700"
+    ; "0070274620000003448717"
+    ; "0070999020000057705860"
+    ; "0110097630009704213797"
+    ; "0110102320010200444955"
+    ; "0110106130010603111097"
+    ; "0110106130010604601847"
+    ; "0110125220012510923535"
+    ; "0110130620013014594573"
+    ; "0110175730017523189801"
+    ; "0110204030020409626051"
+    ; "0110216320021610025999"
+    ; "0110230930023001323933"
+    ; "0110230930023008918451"
+    ; "0110283520028310814652"
+    ; "0110363020036300101822"
+    ; "0110377720037700120402"
+    ; "0110385220038500036492"
+    ; "0110409120040921180719"
+    ; "0110424420042410570553"
+    ; "0110454130045407688379"
+    ; "0110477020047731297428"
+    ; "0110508720050800019135"
+    ; "0110521620052100223696"
+    ; "0110551320055100112719"
+    ; "0140313601697100515896"
+    ; "0140313601697100557414"
+    ; "0140339601630201381276"
+    ; "0140351801684605023087"
+    ; "0140352501684700733410"
+    ; "0140352503684700819149"
+    ; "0140369303631000285682"
+    ; "0140391403672850026131"
+    ; "0140410801680000361629"
+    ; "0140417701630000088992"
+    ; "0140444301650700088379"
+    ; "0140476401626402048153"
+    ; "0150501602000120967405"
+    ; "0168888100008274410158"
+    ; "0168888100000641080265"
+    ; "0170074920000030293449"
+    ; "0170334220000030367766"
+    ; "0200306901000040010097"
+    ; "0200348901000000334779"
+    ; "0200398411000030044362"
+    ; "0200405501000000213951"
+    ; "0200451211000030033962"
+    ; "0200915901000000274233"
+    ; "0340056200560007577005"
+    ; "0720000720000001681136"
+    ; "0720079388000035942322"
+    ; "0720297320000000081418"
+    ; "0720402320000002633754"
+    ; "0930301810100000992800"
+    ; "0930301810100001043132"
+    ; "0930310010100014278400"
+    ; "0930324720100053299139"
+    ; "0930324720100055211111"
+    ; "0940099324001313220028"
+    ; "1500006000005660447200"
+    ; "1500087900051332075196"
+    ; "1910119655011901084646"
+    ; "1910104255110401549353"
+    ; "1910126455012600786400"
+    ; "1910186855018601143246"
+    ; "1910369755036901130632"
+    ; "2850345330000000781858"
+    ; "2850353830094127564171"
+    ; "2850376730000059833142"
+    ; "2850400530094105352671"
+    ; "2850536730094125514871"
+    ; "2850590940090418135201"
+    ; "2850729540000001576069"
+    ; "2850732530000002707016"
+    ; "2850734940094696942458"
+    ; "2850760830094054972021"
+    ; "2850882330094054578991"
+    ; "3110003611000000537014"
+    ; "3110013511000600125046"
+    ; "3300542115420000740012"
+    ; "3300551315510001836040"
+    ; "3860002703000000438381"
+    ; "3860011901000020526675"
+    ; "3860060703000013990500"
+    ; "5729195067928761667584"
+    ; "7362966507842824472644"
+    ; "9498175528566296510521"
+    ]
+  in
+  List.iter
+    (fun n -> check bool (n ^ " should be valid") true (is_valid n))
+    numbers
+
+let test_invalid_length () =
+  Alcotest.check_raises "should raise Invalid_length" Invalid_length (fun () ->
+      ignore (validate "285059094009041"))
+
+let test_invalid_format () =
+  check_raises "should raise Invalid_format" Invalid_format (fun () ->
+      ignore "A850590940090418135201")
+
+let test_valid_number () =
+  check string "should validate correct number" "0940099324001313220028"
+    (validate "0940099324001313220028")
+
+let test_invalid_first_part () =
+  check_raises "should raise Invalid_checksum" Invalid_checksum (fun () ->
+      ignore "1940099324001313220028")
+
+let test_invalid_second_part () =
+  check_raises "should raise Invalid_checksum" Invalid_checksum (fun () ->
+      ignore "0940099324001313220038")
+
+let test_cases =
+  [
+    ( "CBU validation"
+    , [
+        test_case "valid numbers" `Quick test_valid_numbers
+      ; test_case "invalid length" `Quick test_invalid_length
+      ; test_case "invalid format" `Quick test_invalid_format
+      ; test_case "valid number" `Quick test_valid_number
+      ; test_case "invalid first part" `Quick test_invalid_first_part
+      ; test_case "invalid second part" `Quick test_invalid_second_part
+      ] )
+  ]
+
+let () = run "CBU" test_cases