From c226537fb46be727e994bf9abcf0fe819f7b7cfe Mon Sep 17 00:00:00 2001
From: Vinicius Moraes <67981656+ding-an-sich@users.noreply.github.com>
Date: Sun, 9 Jun 2024 13:23:37 -0300
Subject: [PATCH] Handle date and datetime values encoded with numeric cell
 type (#33)

---
 lib/xlsx_reader/parsers/worksheet_parser.ex |   6 ++
 test/compatibility_test.exs                 | 112 +++++++++++---------
 2 files changed, 69 insertions(+), 49 deletions(-)

diff --git a/lib/xlsx_reader/parsers/worksheet_parser.ex b/lib/xlsx_reader/parsers/worksheet_parser.ex
index 43846bc..bace11d 100644
--- a/lib/xlsx_reader/parsers/worksheet_parser.ex
+++ b/lib/xlsx_reader/parsers/worksheet_parser.ex
@@ -373,6 +373,12 @@ defmodule XlsxReader.Parsers.WorksheetParser do
 
       # Numbers
 
+      {"n", :date, value} ->
+        value |> Conversion.to_date(state.workbook.base_date) |> handle_conversion_error()
+
+      {"n", type, value} when type in [:time, :date_time] ->
+        value |> Conversion.to_date_time(state.workbook.base_date) |> handle_conversion_error()
+
       {"n", _, value} ->
         value |> Conversion.to_number(state.number_type) |> handle_conversion_error()
 
diff --git a/test/compatibility_test.exs b/test/compatibility_test.exs
index eab03fe..a04c00d 100644
--- a/test/compatibility_test.exs
+++ b/test/compatibility_test.exs
@@ -2,6 +2,69 @@
 defmodule CompatibilityTest do
   use ExUnit.Case
 
+  describe "elixlsx" do
+    test "file generated by elixlsx" do
+      test_row = [
+        "string1",
+        "",
+        nil,
+        :empty,
+        "string1",
+        "string2",
+        123,
+        true,
+        false
+      ]
+
+      workbook = %Elixlsx.Workbook{
+        sheets: [
+          %Elixlsx.Sheet{
+            name: "sheet1",
+            rows: [
+              test_row
+            ]
+          },
+          %Elixlsx.Sheet{name: "sheet2", rows: []}
+        ]
+      }
+
+      assert {:ok, {_filename, zip_binary}} = Elixlsx.write_to_memory(workbook, "test.xlsx")
+
+      assert {:ok, package} = XlsxReader.open(zip_binary, source: :binary)
+
+      assert ["sheet1", "sheet2"] = XlsxReader.sheet_names(package)
+
+      assert {:ok,
+              [
+                [
+                  "string1",
+                  "",
+                  nil,
+                  nil,
+                  "string1",
+                  "string2",
+                  123.0,
+                  true,
+                  false
+                ]
+              ]} = XlsxReader.sheet(package, "sheet1", blank_value: nil)
+
+      assert {:ok, []} = XlsxReader.sheet(package, "sheet2")
+    end
+
+    test "sheets with dates and datetimes" do
+      s1 = Elixlsx.Sheet.with_name("1") |> Elixlsx.Sheet.set_cell("A1", {{2015, 11, 30}, {21, 20, 38}}, datetime: true)
+      s2 = Elixlsx.Sheet.with_name("2") |> Elixlsx.Sheet.set_cell("A1", {{2015, 11, 30}, {21, 20, 38}}, yyyymmdd: true)
+      wk = %Elixlsx.Workbook{sheets: [s1, s2]}
+
+      {:ok, {_filename, bin}} = Elixlsx.write_to_memory(wk, "test.xlsx")
+      {:ok, package} = XlsxReader.open(bin, source: :binary)
+      {:ok, sheets} = XlsxReader.sheets(package)
+
+      assert [{"1", [[~N[2015-11-30 21:20:38]]]}, {"2", [[~D[2015-11-30]]]}] = sheets
+    end
+  end
+
   test "google_spreadsheet.xlsx" do
     assert {:ok, package} =
              XlsxReader.open(
@@ -37,55 +100,6 @@ defmodule CompatibilityTest do
             ]} = XlsxReader.sheet(package, "merged")
   end
 
-  test "file generated by elixlsx" do
-    test_row = [
-      "string1",
-      "",
-      nil,
-      :empty,
-      "string1",
-      "string2",
-      123,
-      true,
-      false
-    ]
-
-    workbook = %Elixlsx.Workbook{
-      sheets: [
-        %Elixlsx.Sheet{
-          name: "sheet1",
-          rows: [
-            test_row
-          ]
-        },
-        %Elixlsx.Sheet{name: "sheet2", rows: []}
-      ]
-    }
-
-    assert {:ok, {_filename, zip_binary}} = Elixlsx.write_to_memory(workbook, "test.xlsx")
-
-    assert {:ok, package} = XlsxReader.open(zip_binary, source: :binary)
-
-    assert ["sheet1", "sheet2"] = XlsxReader.sheet_names(package)
-
-    assert {:ok,
-            [
-              [
-                "string1",
-                "",
-                nil,
-                nil,
-                "string1",
-                "string2",
-                123.0,
-                true,
-                false
-              ]
-            ]} = XlsxReader.sheet(package, "sheet1", blank_value: nil)
-
-    assert {:ok, []} = XlsxReader.sheet(package, "sheet2")
-  end
-
   test "file with omitted row elements" do
     assert {:ok, package} = XlsxReader.open(TestFixtures.path("omitted_row.xlsx"))