From c04e54753fb30a985b42c3be8530bb94442da9c6 Mon Sep 17 00:00:00 2001
From: Francesco Paolo Severino <96546612+fpseverino@users.noreply.github.com>
Date: Tue, 9 Jul 2024 15:55:14 +0200
Subject: [PATCH] Add support for time zones in `DateTag`. (#131)

* Add support for time zones in `DateTag`.

* Fix tests.
---
 Sources/LeafKit/LeafSyntax/LeafTag.swift |  9 +++++++++
 Tests/LeafKitTests/TagTests.swift        | 24 ++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/Sources/LeafKit/LeafSyntax/LeafTag.swift b/Sources/LeafKit/LeafSyntax/LeafTag.swift
index c8fa105..ecdbb91 100644
--- a/Sources/LeafKit/LeafSyntax/LeafTag.swift
+++ b/Sources/LeafKit/LeafSyntax/LeafTag.swift
@@ -87,6 +87,15 @@ struct DateTag: LeafTag {
                 throw "Unable to convert date format to string"
             }
             formatter.dateFormat = string
+        case 3:
+            guard let string = ctx.parameters[1].string else {
+                throw "Unable to convert date format to string"
+            }
+            formatter.dateFormat = string
+            guard let timeZone = ctx.parameters[2].string else {
+                throw "Unable to convert time zone to string"
+            }
+            formatter.timeZone = TimeZone(identifier: timeZone)
         default:
             throw "invalid parameters provided for date"
         }
diff --git a/Tests/LeafKitTests/TagTests.swift b/Tests/LeafKitTests/TagTests.swift
index 101fe1f..424e875 100644
--- a/Tests/LeafKitTests/TagTests.swift
+++ b/Tests/LeafKitTests/TagTests.swift
@@ -208,6 +208,30 @@ class TagTests: XCTestCase {
         try XCTAssertEqual(render(template, ["now": .int(now)]), expected)
     }
 
+    func testDateWithCustomFormatAndTimeZone() throws {
+        let now = 1604932200 - Calendar.current.timeZone.secondsFromGMT()
+        
+        let templateNewYork = """
+        The date is #date(now, "yyyy-MM-dd'T'HH:mm", "America/New_York")
+        """
+
+        let expectedNewYork = """
+        The date is 2020-11-09T09:30
+        """
+        
+        try XCTAssertEqual(render(templateNewYork, ["now": .int(now)]), expectedNewYork)
+        
+        let templateCalifornia = """
+        The date is #date(now, "yyyy-MM-dd'T'HH:mm", "America/Los_Angeles")
+        """
+
+        let expectedCalifornia = """
+        The date is 2020-11-09T06:30
+        """
+        
+        try XCTAssertEqual(render(templateCalifornia, ["now": .int(now)]), expectedCalifornia)
+    }
+
     func testDumpContext() throws {
         let data: [String: LeafData] = ["value": 12345]
         let template = """