Normalize line endings in JavaScript template messages

babel/messages/jslexer.py

@@ -104,6 +104,9 @@ def unquote_string(string: str) -> str:
     assert string and string[0] == string[-1] and string[0] in '"\'`', (
         'string provided is not properly delimited'
     )
+    if string[0] == '`':
+        # ECMAScript normalizes physical CRLF and CR in template literals.
+        string = string.replace('\r\n', '\n').replace('\r', '\n')
     string = line_join_re.sub('\\1', string[1:-1])
     result: list[str] = []
     add = result.append

tests/messages/test_js_extract.py

@@ -211,3 +211,12 @@ def test_template_string_with_literal_braces() -> None:
     )
     messages = list(extract.extract("javascript", buf, {"gettext": None}, [], {"parse_template_string": True}))
     assert messages == []
+
+
+@pytest.mark.parametrize('line_ending', ['\n', '\r\n', '\r'])
+def test_extract_normalizes_template_line_endings(line_ending):
+    source = f"_('escaped\\r\\n');{line_ending}_(`first{line_ending}second`);"
+    assert list(extract.extract('javascript', BytesIO(source.encode('utf-8')))) == [
+        (1, 'escaped\r\n', [], None),
+        (2, 'first\nsecond', [], None),
+    ]