From fbbb507c53a3a3de02cd96d44b0de04c2ead73b6 Mon Sep 17 00:00:00 2001
From: Harsh <hanandji@amazon.com>
Date: Fri, 15 May 2026 17:40:28 +0200
Subject: [PATCH] fix: remove trailing newline after last rendered line

---
 src/code-view/__tests__/code-view.test.tsx | 27 +++++++++++++++++-----
 src/code-view/highlight/index.tsx          |  2 +-
 src/code-view/internal.tsx                 |  2 +-
 3 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/src/code-view/__tests__/code-view.test.tsx b/src/code-view/__tests__/code-view.test.tsx
index 437aed6..f896f0c 100644
--- a/src/code-view/__tests__/code-view.test.tsx
+++ b/src/code-view/__tests__/code-view.test.tsx
@@ -14,16 +14,24 @@ describe("CodeView", () => {
     cleanup();
   });
   test("correctly renders simple content", () => {
-    render(<CodeView content={"Hello World"}></CodeView>);
-    const wrapper = createWrapper()!.findCodeView();
-    expect(wrapper!.findContent().getElement()).toHaveTextContent("Hello World");
+    const input = "Hello World";
+    render(<CodeView content={input}></CodeView>);
+    const wrapper = createWrapper()!.findCodeView()!;
+    expect(wrapper.findContent().getElement().textContent).toBe(input);
   });
 
   test("correctly renders multi line content", () => {
-    render(<CodeView content={`# Hello World\n\nThis is a markdown example.`}></CodeView>);
+    const input = `# Hello World\n\nThis is a markdown example.`;
+    render(<CodeView content={input}></CodeView>);
     const wrapper = createWrapper()!.findCodeView()!;
-    const content = wrapper.findContent();
-    expect(content.getElement()).toHaveTextContent("# Hello World This is a markdown example.");
+    expect(wrapper.findContent().getElement().textContent).toBe(input);
+  });
+
+  test("preserves a trailing newline when present in the input", () => {
+    const input = "a\nb\n";
+    render(<CodeView content={input}></CodeView>);
+    const wrapper = createWrapper()!.findCodeView()!;
+    expect(wrapper.findContent().getElement().textContent).toBe(input);
   });
 
   test("correctly renders table markup with line numbers", () => {
@@ -102,6 +110,13 @@ describe("CodeView", () => {
     expect(getByText(element, '"world"')).toHaveClass("ace_string");
   });
 
+  test("renders highlighted content without trailing newline", () => {
+    const input = 'const hello: string = "world";';
+    render(<CodeView content={input} highlight={typescriptHighlightRules}></CodeView>);
+    const wrapper = createWrapper()!.findCodeView()!;
+    expect(wrapper.findContent().getElement().textContent).toBe(input);
+  });
+
   test("sets nowrap class to line if linesWrapping undefined", () => {
     render(<CodeView content={"Hello World"}></CodeView>);
     const wrapper = createWrapper().findCodeView()!;
diff --git a/src/code-view/highlight/index.tsx b/src/code-view/highlight/index.tsx
index d0103e8..84a9840 100644
--- a/src/code-view/highlight/index.tsx
+++ b/src/code-view/highlight/index.tsx
@@ -25,7 +25,7 @@ export function createHighlight(rules: Ace.HighlightRules): CreateHighlightType
                 token.value
               );
             })}
-            {"\n"}
+            {lineIndex < tokens.length - 1 ? "\n" : ""}
           </Fragment>
         ))}
       </span>
diff --git a/src/code-view/internal.tsx b/src/code-view/internal.tsx
index 496c640..48f3e4e 100644
--- a/src/code-view/internal.tsx
+++ b/src/code-view/internal.tsx
@@ -28,7 +28,7 @@ const textHighlight = (code: string) => {
       {lines.map((line, lineIndex) => (
         <span key={lineIndex}>
           {line}
-          {"\n"}
+          {lineIndex < lines.length - 1 ? "\n" : ""}
         </span>
       ))}
     </span>