Fix seconds being returned as seconds.milliseconds in timestamps

CHANGELOG.md

@@ -3,6 +3,9 @@
 ## v0.15.0 - Unreleased
 
 - Ensure `ssl` and `pgo` are running before using `gleam_pgo`.
+- Fix a bug where timestamps are returned as `#(#(Int, Int, Int), #(Int, Int, Float))`
+  leading `decode_timestamp` to fail. `decode_timestamp` now properly returns
+  `#(#(Int, Int, Int), #(Int, Int, Float))`.
 
 ## v0.14.0 - 2024-08-15
 

README.md

@@ -98,6 +98,16 @@ By default, `pgo` will return every selected value from your query as a tuple.
 In case you want a different output, you can activate `rows_as_maps` in `Config`.
 Once activated, every returned rows will take the form of a `Dict`.
 
+## About timestamps
+
+If you're used to manage timestamps in Postgres, you know timestamp are stored
+as bytes, and clients transforms them in their desired formats. `pgo` uses the
+Erlang datetime convention, i.e. managing a timestamp as a tuple
+`#(#(year, month, day), #(hour, minutes, seconds))`. When querying a timestamp,
+unless you're casting it (in ISO-8601 for example) voluntarily in your SQL query,
+`pgo` will give you such a tuple. You're expected to decode it using
+`pgo.decode_timestamp` that will do the work of decoding it for you.
+
 ## Atom generation
 
 Creating a connection pool with the `pgo.connect` function dynamically generates

src/gleam/pgo.gleam

@@ -3,6 +3,7 @@
 //// Gleam wrapper around pgo library
 
 import gleam/dynamic.{type DecodeErrors, type Decoder, type Dynamic}
+import gleam/int
 import gleam/list
 import gleam/option.{type Option, None, Some}
 import gleam/result
@@ -170,7 +171,7 @@ pub fn array(a: List(a)) -> Value
 
 /// Coerce a timestamp represented as `#(#(year, month, day), #(hour, minute, second))` into a `Value`.
 @external(erlang, "gleam_pgo_ffi", "coerce")
-pub fn timestamp(a: #(#(Int, Int, Int), #(Int, Int, Int))) -> Value
+pub fn timestamp(a: #(#(Int, Int, Int), #(Int, Int, Float))) -> Value
 
 /// Coerce a date represented as `#(year, month, day)` into a `Value`.
 @external(erlang, "gleam_pgo_ffi", "coerce")
@@ -525,16 +526,24 @@ pub fn error_code_name(error_code: String) -> Result(String, Nil) {
   }
 }
 
-/// Checks to see if the value is formatted as `#(#(Int, Int, Int), #(Int, Int, Int))`
-/// to represent `#(#(year, month, day), #(hour, minute, second))`, and returns the
+/// Checks to see if the value is formatted as `#(#(Int, Int, Int), #(Int, Int, Float))`
+/// to represent `#(#(year, month, day), #(hour, minute, second.milliseconds))`, and returns the
 /// value if it is.
 pub fn decode_timestamp(value: dynamic.Dynamic) {
   dynamic.tuple2(
     dynamic.tuple3(dynamic.int, dynamic.int, dynamic.int),
-    dynamic.tuple3(dynamic.int, dynamic.int, dynamic.int),
+    dynamic.tuple3(dynamic.int, dynamic.int, decode_seconds),
   )(value)
 }
 
+fn decode_int_to_float(value: dynamic.Dynamic) {
+  dynamic.int(value) |> result.map(int.to_float)
+}
+
+fn decode_seconds(value: dynamic.Dynamic) {
+  dynamic.any([dynamic.float, decode_int_to_float])(value)
+}
+
 /// Checks to see if the value is formatted as `#(Int, Int, Int)` to represent a date
 /// as `#(year, month, day)`, and returns the value if it is.
 pub fn decode_date(value: dynamic.Dynamic) {

test/gleam/pgo_test.gleam

@@ -150,7 +150,7 @@ pub fn selecting_rows_test() {
   |> should.equal(1)
   returned.rows
   |> should.equal([
-    #(id, "neo", True, ["black"], #(#(2022, 10, 10), #(11, 30, 30)), #(
+    #(id, "neo", True, ["black"], #(#(2022, 10, 10), #(11, 30, 30.0)), #(
       2020,
       3,
       4,
@@ -362,7 +362,7 @@ pub fn array_test() {
 pub fn datetime_test() {
   start_default()
   |> assert_roundtrip(
-    #(#(2022, 10, 12), #(11, 30, 33)),
+    #(#(2022, 10, 12), #(11, 30, 33.0)),
     "timestamp",
     pgo.timestamp,
     pgo.decode_timestamp,
@@ -464,7 +464,7 @@ pub fn expected_maps_test() {
   |> should.equal(1)
   returned.rows
   |> should.equal([
-    #(id, "neo", True, ["black"], #(#(2022, 10, 10), #(11, 30, 30)), #(
+    #(id, "neo", True, ["black"], #(#(2022, 10, 10), #(11, 30, 30.0)), #(
       2020,
       3,
       4,