From 94f43c79d0edf980294bdd700f8bffbc6cac1c69 Mon Sep 17 00:00:00 2001
From: Jacob Richman <jacob314@gmail.com>
Date: Mon, 29 Sep 2025 13:38:27 -0700
Subject: [PATCH] Fix markdown rendering on Windows (#10185)

---
 .../cli/src/ui/utils/MarkdownDisplay.test.tsx | 256 +++++++++---------
 packages/cli/src/ui/utils/MarkdownDisplay.tsx |   3 +-
 .../MarkdownDisplay.test.tsx.snap             | 124 +++++++--
 3 files changed, 238 insertions(+), 145 deletions(-)

diff --git a/packages/cli/src/ui/utils/MarkdownDisplay.test.tsx b/packages/cli/src/ui/utils/MarkdownDisplay.test.tsx
index 634888b07c..927a69e154 100644
--- a/packages/cli/src/ui/utils/MarkdownDisplay.test.tsx
+++ b/packages/cli/src/ui/utils/MarkdownDisplay.test.tsx
@@ -7,7 +7,6 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { MarkdownDisplay } from './MarkdownDisplay.js';
 import { LoadedSettings } from '../../config/settings.js';
-import { EOL } from 'node:os';
 import { renderWithProviders } from '../../test-utils/render.js';
 
 describe('<MarkdownDisplay />', () => {
@@ -36,132 +35,138 @@ describe('<MarkdownDisplay />', () => {
     expect(lastFrame()).toMatchSnapshot();
   });
 
-  it('renders headers with correct levels', () => {
-    const text = `
+  const lineEndings = [
+    { name: 'Windows', eol: '\r\n' },
+    { name: 'Unix', eol: '\n' },
+  ];
+
+  describe.each(lineEndings)('with $name line endings', ({ eol }) => {
+    it('renders headers with correct levels', () => {
+      const text = `
 # Header 1
 ## Header 2
 ### Header 3
 #### Header 4
-`.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+`.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('renders a fenced code block with a language', () => {
-    const text = '```javascript\nconst x = 1;\nconsole.log(x);\n```'.replace(
-      /\n/g,
-      EOL,
-    );
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+    it('renders a fenced code block with a language', () => {
+      const text = '```javascript\nconst x = 1;\nconsole.log(x);\n```'.replace(
+        /\n/g,
+        eol,
+      );
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('renders a fenced code block without a language', () => {
-    const text = '```\nplain text\n```'.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+    it('renders a fenced code block without a language', () => {
+      const text = '```\nplain text\n```'.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('handles unclosed (pending) code blocks', () => {
-    const text = '```typescript\nlet y = 2;'.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} isPending={true} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+    it('handles unclosed (pending) code blocks', () => {
+      const text = '```typescript\nlet y = 2;'.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} isPending={true} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('renders unordered lists with different markers', () => {
-    const text = `
+    it('renders unordered lists with different markers', () => {
+      const text = `
 - item A
 * item B
 + item C
-`.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+`.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('renders nested unordered lists', () => {
-    const text = `
+    it('renders nested unordered lists', () => {
+      const text = `
 * Level 1
   * Level 2
     * Level 3
-`.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+`.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('renders ordered lists', () => {
-    const text = `
+    it('renders ordered lists', () => {
+      const text = `
 1. First item
 2. Second item
-`.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+`.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('renders horizontal rules', () => {
-    const text = `
+    it('renders horizontal rules', () => {
+      const text = `
 Hello
 ---
 World
 ***
 Test
-`.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+`.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('renders tables correctly', () => {
-    const text = `
+    it('renders tables correctly', () => {
+      const text = `
 | Header 1 | Header 2 |
 |----------|:--------:|
 | Cell 1   | Cell 2   |
 | Cell 3   | Cell 4   |
-`.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+`.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('handles a table at the end of the input', () => {
-    const text = `
+    it('handles a table at the end of the input', () => {
+      const text = `
 Some text before.
 | A | B |
 |---|
-| 1 | 2 |`.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+| 1 | 2 |`.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('inserts a single space between paragraphs', () => {
-    const text = `Paragraph 1.
+    it('inserts a single space between paragraphs', () => {
+      const text = `Paragraph 1.
 
-Paragraph 2.`.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+Paragraph 2.`.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('correctly parses a mix of markdown elements', () => {
-    const text = `
+    it('correctly parses a mix of markdown elements', () => {
+      const text = `
 # Main Title
 
 Here is a paragraph.
@@ -174,42 +179,43 @@ some code
 \`\`\`
 
 Another paragraph.
-`.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-  });
+`.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+    });
 
-  it('hides line numbers in code blocks when showLineNumbers is false', () => {
-    const text = '```javascript\nconst x = 1;\n```'.replace(/\n/g, EOL);
-    const settings = new LoadedSettings(
-      { path: '', settings: {}, originalSettings: {} },
-      { path: '', settings: {}, originalSettings: {} },
-      {
-        path: '',
-        settings: { ui: { showLineNumbers: false } },
-        originalSettings: { ui: { showLineNumbers: false } },
-      },
-      { path: '', settings: {}, originalSettings: {} },
-      true,
-      new Set(),
-    );
+    it('hides line numbers in code blocks when showLineNumbers is false', () => {
+      const text = '```javascript\nconst x = 1;\n```'.replace(/\n/g, eol);
+      const settings = new LoadedSettings(
+        { path: '', settings: {}, originalSettings: {} },
+        { path: '', settings: {}, originalSettings: {} },
+        {
+          path: '',
+          settings: { ui: { showLineNumbers: false } },
+          originalSettings: { ui: { showLineNumbers: false } },
+        },
+        { path: '', settings: {}, originalSettings: {} },
+        true,
+        new Set(),
+      );
 
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-      { settings },
-    );
-    expect(lastFrame()).toMatchSnapshot();
-    expect(lastFrame()).not.toContain(' 1 ');
-  });
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+        { settings },
+      );
+      expect(lastFrame()).toMatchSnapshot();
+      expect(lastFrame()).not.toContain(' 1 ');
+    });
 
-  it('shows line numbers in code blocks by default', () => {
-    const text = '```javascript\nconst x = 1;\n```'.replace(/\n/g, EOL);
-    const { lastFrame } = renderWithProviders(
-      <MarkdownDisplay {...baseProps} text={text} />,
-    );
-    expect(lastFrame()).toMatchSnapshot();
-    expect(lastFrame()).toContain(' 1 ');
+    it('shows line numbers in code blocks by default', () => {
+      const text = '```javascript\nconst x = 1;\n```'.replace(/\n/g, eol);
+      const { lastFrame } = renderWithProviders(
+        <MarkdownDisplay {...baseProps} text={text} />,
+      );
+      expect(lastFrame()).toMatchSnapshot();
+      expect(lastFrame()).toContain(' 1 ');
+    });
   });
 });
diff --git a/packages/cli/src/ui/utils/MarkdownDisplay.tsx b/packages/cli/src/ui/utils/MarkdownDisplay.tsx
index 2baea99884..da6bf21aaf 100644
--- a/packages/cli/src/ui/utils/MarkdownDisplay.tsx
+++ b/packages/cli/src/ui/utils/MarkdownDisplay.tsx
@@ -6,7 +6,6 @@
 
 import React from 'react';
 import { Text, Box } from 'ink';
-import { EOL } from 'node:os';
 import { theme } from '../semantic-colors.js';
 import { colorizeCode } from './CodeColorizer.js';
 import { TableRenderer } from './TableRenderer.js';
@@ -35,7 +34,7 @@ const MarkdownDisplayInternal: React.FC<MarkdownDisplayProps> = ({
 }) => {
   if (!text) return <></>;
 
-  const lines = text.split(EOL);
+  const lines = text.split(/\r?\n/);
   const headerRegex = /^ *(#{1,4}) +(.*)/;
   const codeFenceRegex = /^ *(`{3,}|~{3,}) *(\w*?) *$/;
   const ulItemRegex = /^([ \t]*)([-*+]) +(.*)/;
diff --git a/packages/cli/src/ui/utils/__snapshots__/MarkdownDisplay.test.tsx.snap b/packages/cli/src/ui/utils/__snapshots__/MarkdownDisplay.test.tsx.snap
index 223c293b19..c340dc8f61 100644
--- a/packages/cli/src/ui/utils/__snapshots__/MarkdownDisplay.test.tsx.snap
+++ b/packages/cli/src/ui/utils/__snapshots__/MarkdownDisplay.test.tsx.snap
@@ -1,6 +1,10 @@
 // Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
-exports[`<MarkdownDisplay /> > correctly parses a mix of markdown elements 1`] = `
+exports[`<MarkdownDisplay /> > renders a simple paragraph 1`] = `"Hello, world."`;
+
+exports[`<MarkdownDisplay /> > renders nothing for empty text 1`] = `""`;
+
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > correctly parses a mix of markdown elements 1`] = `
 "Main Title
 
 Here is a paragraph.
@@ -14,33 +18,31 @@ Another paragraph.
 "
 `;
 
-exports[`<MarkdownDisplay /> > handles a table at the end of the input 1`] = `
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > handles a table at the end of the input 1`] = `
 "Some text before.
 | A | B |
 |---|
 | 1 | 2 |"
 `;
 
-exports[`<MarkdownDisplay /> > handles unclosed (pending) code blocks 1`] = `" 1 let y = 2;"`;
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > handles unclosed (pending) code blocks 1`] = `" 1 let y = 2;"`;
 
-exports[`<MarkdownDisplay /> > hides line numbers in code blocks when showLineNumbers is false 1`] = `" const x = 1;"`;
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > hides line numbers in code blocks when showLineNumbers is false 1`] = `" const x = 1;"`;
 
-exports[`<MarkdownDisplay /> > inserts a single space between paragraphs 1`] = `
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > inserts a single space between paragraphs 1`] = `
 "Paragraph 1.
 
 Paragraph 2."
 `;
 
-exports[`<MarkdownDisplay /> > renders a fenced code block with a language 1`] = `
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > renders a fenced code block with a language 1`] = `
 " 1 const x = 1;
  2 console.log(x);"
 `;
 
-exports[`<MarkdownDisplay /> > renders a fenced code block without a language 1`] = `" 1 plain text"`;
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > renders a fenced code block without a language 1`] = `" 1 plain text"`;
 
-exports[`<MarkdownDisplay /> > renders a simple paragraph 1`] = `"Hello, world."`;
-
-exports[`<MarkdownDisplay /> > renders headers with correct levels 1`] = `
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > renders headers with correct levels 1`] = `
 "Header 1
 Header 2
 Header 3
@@ -48,7 +50,7 @@ Header 4
 "
 `;
 
-exports[`<MarkdownDisplay /> > renders horizontal rules 1`] = `
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > renders horizontal rules 1`] = `
 "Hello
 ---
 World
@@ -57,22 +59,20 @@ Test
 "
 `;
 
-exports[`<MarkdownDisplay /> > renders nested unordered lists 1`] = `
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > renders nested unordered lists 1`] = `
 " * Level 1
    * Level 2
      * Level 3
 "
 `;
 
-exports[`<MarkdownDisplay /> > renders nothing for empty text 1`] = `""`;
-
-exports[`<MarkdownDisplay /> > renders ordered lists 1`] = `
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > renders ordered lists 1`] = `
 " 1. First item
  2. Second item
 "
 `;
 
-exports[`<MarkdownDisplay /> > renders tables correctly 1`] = `
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > renders tables correctly 1`] = `
 "
 ┌──────────┬──────────┐
 │ Header 1 │ Header 2 │
@@ -83,11 +83,99 @@ exports[`<MarkdownDisplay /> > renders tables correctly 1`] = `
 "
 `;
 
-exports[`<MarkdownDisplay /> > renders unordered lists with different markers 1`] = `
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > renders unordered lists with different markers 1`] = `
 " - item A
  * item B
  + item C
 "
 `;
 
-exports[`<MarkdownDisplay /> > shows line numbers in code blocks by default 1`] = `" 1 const x = 1;"`;
+exports[`<MarkdownDisplay /> > with 'Unix' line endings > shows line numbers in code blocks by default 1`] = `" 1 const x = 1;"`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > correctly parses a mix of markdown elements 1`] = `
+"Main Title
+
+Here is a paragraph.
+
+ - List item 1
+ - List item 2
+
+ 1 some code
+
+Another paragraph.
+"
+`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > handles a table at the end of the input 1`] = `
+"Some text before.
+| A | B |
+|---|
+| 1 | 2 |"
+`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > handles unclosed (pending) code blocks 1`] = `" 1 let y = 2;"`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > hides line numbers in code blocks when showLineNumbers is false 1`] = `" const x = 1;"`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > inserts a single space between paragraphs 1`] = `
+"Paragraph 1.
+
+Paragraph 2."
+`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > renders a fenced code block with a language 1`] = `
+" 1 const x = 1;
+ 2 console.log(x);"
+`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > renders a fenced code block without a language 1`] = `" 1 plain text"`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > renders headers with correct levels 1`] = `
+"Header 1
+Header 2
+Header 3
+Header 4
+"
+`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > renders horizontal rules 1`] = `
+"Hello
+---
+World
+---
+Test
+"
+`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > renders nested unordered lists 1`] = `
+" * Level 1
+   * Level 2
+     * Level 3
+"
+`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > renders ordered lists 1`] = `
+" 1. First item
+ 2. Second item
+"
+`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > renders tables correctly 1`] = `
+"
+┌──────────┬──────────┐
+│ Header 1 │ Header 2 │
+├──────────┼──────────┤
+│ Cell 1   │ Cell 2   │
+│ Cell 3   │ Cell 4   │
+└──────────┴──────────┘
+"
+`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > renders unordered lists with different markers 1`] = `
+" - item A
+ * item B
+ + item C
+"
+`;
+
+exports[`<MarkdownDisplay /> > with 'Windows' line endings > shows line numbers in code blocks by default 1`] = `" 1 const x = 1;"`;