Add ltxtquery support (#735)

Author: realglebivanov

.github/workflows/ci.yml

@@ -69,7 +69,7 @@ jobs:
           otp-version: ${{matrix.pair.otp}}
           elixir-version: ${{matrix.pair.elixir}}
 
-      - uses: actions/cache@v2
+      - uses: actions/cache@v4
         with:
           path: |
             deps

lib/postgrex/extensions/ltxtquery.ex

@@ -0,0 +1,37 @@
+defmodule Postgrex.Extensions.Ltxtquery do
+  @moduledoc false
+  import Postgrex.BinaryUtils, warn: false
+  use Postgrex.BinaryExtension, type: "ltxtquery"
+
+  @impl true
+  def init(opts), do: Keyword.get(opts, :decode_binary, :copy)
+
+  # ltxtquery binary formats are versioned
+  # https://github.com/postgres/postgres/blob/master/contrib/ltree/ltxtquery_io.c
+  @impl true
+  def encode(_state) do
+    quote location: :keep, generated: true do
+      bin when is_binary(bin) ->
+        version = 1
+        size = byte_size(bin) + 1
+        [<<size::int32(), version::int8()>> | bin]
+    end
+  end
+
+  @impl true
+  def decode(:reference) do
+    quote location: :keep do
+      <<len::int32(), bin::binary-size(len)>> ->
+        <<_version::int8(), ltxtquery::binary>> = bin
+        ltxtquery
+    end
+  end
+
+  def decode(:copy) do
+    quote location: :keep do
+      <<len::int32(), bin::binary-size(len)>> ->
+        <<_version::int8(), ltxtquery::binary>> = bin
+        :binary.copy(ltxtquery)
+    end
+  end
+end

lib/postgrex/utils.ex

@@ -22,6 +22,7 @@ defmodule Postgrex.Utils do
     Postgrex.Extensions.LineSegment,
     Postgrex.Extensions.Lquery,
     Postgrex.Extensions.Ltree,
+    Postgrex.Extensions.Ltxtquery,
     Postgrex.Extensions.MACADDR,
     Postgrex.Extensions.Multirange,
     Postgrex.Extensions.Name,

test/query_test.exs

@@ -765,6 +765,12 @@ defmodule QueryTest do
     assert [[ltree]] == query("SELECT '#{ltree}'::ltree", [])
   end
 
+  @tag min_pg_version: "13.0"
+  test "decode ltxtquery", context do
+    ltxtquery = "Europe% & Russia@* & !( Transportation & Test )"
+    assert [[ltxtquery]] == query("SELECT '#{ltxtquery}'::ltxtquery", [])
+  end
+
   test "encode oid and its aliases", context do
     # oid's range is 0 to 4294967295
     assert [[0]] = query("select $1::oid;", [0])
@@ -1533,6 +1539,12 @@ defmodule QueryTest do
     assert [[ltree]] == query("SELECT $1::ltree", [ltree])
   end
 
+  @tag min_pg_version: "13.0"
+  test "encode ltxtquery", context do
+    ltxtquery = "Europe% & Russia@* & !( Transportation & Test )"
+    assert [[ltxtquery]] == query("SELECT $1::ltxtquery", [ltxtquery])
+  end
+
   test "fail on encode arrays", context do
     assert_raise ArgumentError, "nested lists must have lists with matching lengths", fn ->
       query("SELECT $1::integer[]", [[[1], [1, 2]]])