unit tests to capture current behaviour of this PR (WIP)

tests/test_rich_markup_mode.py

@@ -1,3 +1,6 @@
+from typing import List
+
+import pytest
 import typer
 import typer.completion
 from typer.testing import CliRunner
@@ -38,3 +41,67 @@ def main(arg: str):
 
     result = runner.invoke(app, ["--help"])
     assert any(c in result.stdout for c in rounded)
+
+
+@pytest.mark.parametrize(
+    "mode,lines",
+    [
+        ("markdown", ["First line", "", "Line 1", "", "Line 2", ""]),
+        ("rich", ["First line", "", "Line 1", "", "Line 2", ""]),
+        ("none", ["First line", "", "Line 1", "Line 2", ""]),
+    ],
+)
+def test_markup_mode_newline_pr815(mode: str, lines: List[str]):
+    app = typer.Typer(rich_markup_mode=mode)
+
+    @app.command()
+    def main():
+        """First line
+
+        Line 1
+
+        Line 2
+        """
+        pass
+
+    assert app.rich_markup_mode == mode
+
+    result = runner.invoke(app, ["--help"])
+    result_lines = [line.strip() for line in result.stdout.split("\n")]
+    assert any(c in result.stdout for c in rounded)
+    help_start = result_lines.index("First line")
+    options_start = [i for i, row in enumerate(result_lines) if "Options" in row][0]
+    assert help_start != -1
+    assert result_lines[help_start:options_start] == lines
+
+
+@pytest.mark.parametrize(
+    "mode,lines",
+    [
+        ("markdown", ["First line", "", "Line 1 Line 2 Line 3", ""]),
+        ("rich", ["First line", "", "Line 1", "Line 2", "Line 3", ""]),
+        ("none", ["First line", "", "Line 1 Line 2 Line 3", ""]),
+    ],
+)
+def test_markup_mode_newline_issue447(mode: str, lines: List[str]):
+    app = typer.Typer(rich_markup_mode=mode)
+
+    @app.command()
+    def main():
+        """First line
+
+        Line 1
+        Line 2
+        Line 3
+        """
+        pass
+
+    assert app.rich_markup_mode == mode
+
+    result = runner.invoke(app, ["--help"])
+    result_lines = [line.strip() for line in result.stdout.split("\n")]
+    assert any(c in result.stdout for c in rounded)
+    help_start = result_lines.index("First line")
+    options_start = [i for i, row in enumerate(result_lines) if "Options" in row][0]
+    assert help_start != -1
+    assert result_lines[help_start:options_start] == lines