From 0a2e711351da8577e72b6fa182e024ab0e107ebb Mon Sep 17 00:00:00 2001
From: mike <98623181+1Kinoti@users.noreply.github.com>
Date: Mon, 27 Feb 2023 23:17:58 +0300
Subject: [PATCH] fix: allow subtraction of durations from dates (#8247)

`date` - `duration` is
[implemented](https://github.com/nushell/nushell/blob/ba5258d7165423b360edf1747d0ffec00052db13/crates/nu-protocol/src/value/mod.rs#L2145)
but the type checker rejects it

this pr fixes that
---
 crates/nu-parser/src/type_check.rs |  1 +
 src/tests/test_type_check.rs       | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/crates/nu-parser/src/type_check.rs b/crates/nu-parser/src/type_check.rs
index 13c0f3c93d..fb8fada23f 100644
--- a/crates/nu-parser/src/type_check.rs
+++ b/crates/nu-parser/src/type_check.rs
@@ -107,6 +107,7 @@ pub fn math_result_type(
                 (Type::Int, Type::Float) => (Type::Float, None),
                 (Type::Float, Type::Float) => (Type::Float, None),
                 (Type::Date, Type::Date) => (Type::Duration, None),
+                (Type::Date, Type::Duration) => (Type::Date, None),
                 (Type::Duration, Type::Duration) => (Type::Duration, None),
                 (Type::Filesize, Type::Filesize) => (Type::Filesize, None),
 
diff --git a/src/tests/test_type_check.rs b/src/tests/test_type_check.rs
index cf022ad57b..dfac8a3e2a 100644
--- a/src/tests/test_type_check.rs
+++ b/src/tests/test_type_check.rs
@@ -24,3 +24,17 @@ fn number_int() -> TestResult {
 fn number_float() -> TestResult {
     run_test(r#"def foo [x:number] { $x }; foo 1.4"#, "1.4")
 }
+
+#[test]
+fn date_minus_duration() -> TestResult {
+    let input = "2023-04-22 - 2day | date format %Y-%m-%d";
+    let expected = "2023-04-20";
+    run_test(input, expected)
+}
+
+#[test]
+fn date_plus_duration() -> TestResult {
+    let input = "2023-04-18 + 2day | date format %Y-%m-%d";
+    let expected = "2023-04-20";
+    run_test(input, expected)
+}