From 573afbc44f2ee4592660ec53b0bfff2dce3226f6 Mon Sep 17 00:00:00 2001
From: memothelemo <dev@memothelemo.xyz>
Date: Wed, 1 Jan 2025 19:14:56 +0800
Subject: [PATCH] Fix invalid emit of escaped new line character in strings

---
 .../nodes/expressions/renderStringLiteral.ts   |  4 +++-
 .../fields/renderInterpolatedStringPart.ts     |  3 ++-
 .../util/stripBackslashInEscapedNewLines.ts    | 18 ++++++++++++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 src/LuauRenderer/util/stripBackslashInEscapedNewLines.ts

diff --git a/src/LuauRenderer/nodes/expressions/renderStringLiteral.ts b/src/LuauRenderer/nodes/expressions/renderStringLiteral.ts
index 18d86ea..0d900bd 100644
--- a/src/LuauRenderer/nodes/expressions/renderStringLiteral.ts
+++ b/src/LuauRenderer/nodes/expressions/renderStringLiteral.ts
@@ -1,6 +1,7 @@
 import luau from "LuauAST";
 import { RenderState } from "LuauRenderer";
 import { getSafeBracketEquals } from "LuauRenderer/util/getSafeBracketEquals";
+import { stripBackslashInEscapedNewLines } from "LuauRenderer/util/stripBackslashInEscapedNewLines";
 
 function needsBracketSpacing(node: luau.StringLiteral) {
 	const parent = node.parent;
@@ -32,6 +33,7 @@ export function renderStringLiteral(state: RenderState, node: luau.StringLiteral
 	} else {
 		const eqStr = getSafeBracketEquals(node.value);
 		const spacing = needsBracketSpacing(node) ? " " : "";
-		return `${spacing}[${eqStr}[${node.value}]${eqStr}]${spacing}`;
+		const value = stripBackslashInEscapedNewLines(node.value);
+		return `${spacing}[${eqStr}[${value}]${eqStr}]${spacing}`;
 	}
 }
diff --git a/src/LuauRenderer/nodes/fields/renderInterpolatedStringPart.ts b/src/LuauRenderer/nodes/fields/renderInterpolatedStringPart.ts
index f246820..fdc4fd9 100644
--- a/src/LuauRenderer/nodes/fields/renderInterpolatedStringPart.ts
+++ b/src/LuauRenderer/nodes/fields/renderInterpolatedStringPart.ts
@@ -1,9 +1,10 @@
 import luau from "LuauAST";
 import { RenderState } from "LuauRenderer";
+import { stripBackslashInEscapedNewLines } from "LuauRenderer/util/stripBackslashInEscapedNewLines";
 
 export function renderInterpolatedStringPart(state: RenderState, node: luau.InterpolatedStringPart) {
 	return (
-		node.text
+		stripBackslashInEscapedNewLines(node.text)
 			// escape braces, but do not touch braces within unicode escape codes
 			.replace(/(\\u{[a-fA-F0-9]+})|([{}])/g, (_, unicodeEscape, brace) => unicodeEscape ?? "\\" + brace)
 			// escape newlines, captures a CR with optionally an LF after it or just an LF on its own
diff --git a/src/LuauRenderer/util/stripBackslashInEscapedNewLines.ts b/src/LuauRenderer/util/stripBackslashInEscapedNewLines.ts
new file mode 100644
index 0000000..5e80a72
--- /dev/null
+++ b/src/LuauRenderer/util/stripBackslashInEscapedNewLines.ts
@@ -0,0 +1,18 @@
+/**
+ * Strips off any excess backslash if it is escaped with `\n`
+ *
+ * **From**:
+ * ```ts
+ * "Hello\
+ * World!"
+ * ```
+ *
+ * **To**:
+ * ```lua
+ * [[Hello
+ * World!]]
+ * ```
+ */
+export function stripBackslashInEscapedNewLines(value: string) {
+	return value.replace(/\\(\r\n?|\n)/g, "$1");
+}