From 547e48cc5f8d98380dd8a7226ce630d3aa3b2245 Mon Sep 17 00:00:00 2001
From: Michael S <54802506+roya1v@users.noreply.github.com>
Date: Mon, 13 May 2024 15:31:12 +0200
Subject: [PATCH] Allow escaped quotes in tag parameters (#124)

* add escaping with "$"

* Add new constant

* Change escaping to double back slash

---------

Co-authored-by: Sam Bishop <sambobjr@gmail.com>
---
 Sources/LeafKit/LeafLexer/LeafLexer.swift | 12 +++++++++++-
 Tests/LeafKitTests/LeafTests.swift        | 10 ++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/Sources/LeafKit/LeafLexer/LeafLexer.swift b/Sources/LeafKit/LeafLexer/LeafLexer.swift
index 09228fd0..206209a0 100644
--- a/Sources/LeafKit/LeafLexer/LeafLexer.swift
+++ b/Sources/LeafKit/LeafLexer/LeafLexer.swift
@@ -160,7 +160,7 @@ internal struct LeafLexer {
             case .comma:
                 return .parameterDelimiter
             case .quote:
-                let read = src.readWhile { $0 != .quote && $0 != .newLine }
+                let read = readWithEscapingQuotes(src: &src)
                 guard src.peek() == .quote else {
                     throw LexerError(.unterminatedStringLiteral, src: src, lexed: lexed)
                 }
@@ -269,4 +269,14 @@ internal struct LeafLexer {
             return .parameter(.variable(name: name))
         }
     }
+
+    private func readWithEscapingQuotes(src: inout LeafRawTemplate) -> String {
+        let read = src.readWhile { $0 != .quote && $0 != .newLine }
+        if read.last == .backSlash && src.peek() == .quote {
+            src.pop()
+            return read.dropLast() + "\"" + readWithEscapingQuotes(src: &src)
+        } else {
+            return read
+        }
+    }
 }
diff --git a/Tests/LeafKitTests/LeafTests.swift b/Tests/LeafKitTests/LeafTests.swift
index de4c302a..9dbb7e09 100644
--- a/Tests/LeafKitTests/LeafTests.swift
+++ b/Tests/LeafKitTests/LeafTests.swift
@@ -191,6 +191,16 @@ final class LeafTests: XCTestCase {
         try XCTAssertEqual(render(template, [:]), expected)
     }
 
+    func testEscapingQuote() throws {
+        let template = """
+        #("foo \\"bar\\"")
+        """
+        let expected = """
+        foo "bar"
+        """
+        try XCTAssertEqual(render(template), expected)
+    }
+
     func testCount() throws {
         let template = """
         count: #count(array)