Add line break shortcode support

tests/test_text/test_text_counting.py

@@ -47,6 +47,7 @@ def testTextCounting_preProcessText():
         "[vspace:3]\n\n"
         "[New Page]\n\n"
         "[footnote:abcd]\n\n"
+        "[br]\n\n"
         "Dashes\u2013and even longer\u2014dashes.\n\n"
     )
 
@@ -60,7 +61,7 @@ def testTextCounting_preProcessText():
         "#### Heading Four",
         "", "", "",
         "A paragraph.", "",
-        "", "", "", "", "", "",
+        "", "", "", "", "", "", "", "",
         "Dashes and even longer dashes.", ""
     ]
 
@@ -68,7 +69,7 @@ def testTextCounting_preProcessText():
     assert preProcessText(text, keepHeaders=False) == [
         "", "", "",
         "A paragraph.", "",
-        "", "", "", "", "", "",
+        "", "", "", "", "", "", "", "",
         "Dashes and even longer dashes.", ""
     ]
 

tests/test_text/test_text_patterns.py

@@ -198,6 +198,17 @@ def testTextPatterns_ShortcodesPlain():
 
     assert allMatches(regEx, "one [x]two[/x] three") == []
 
+    # Line Break Substitution
+    # =======================
+    regEx = REGEX_PATTERNS.lineBreak
+
+    assert regEx.sub("\n", "one[br]two") == "one\ntwo"
+    assert regEx.sub("\n", "one[br]\ntwo") == "one\ntwo"
+    assert regEx.sub("\n", "one[br]\n\ntwo") == "one\n\ntwo"
+    assert regEx.sub("\n", "one[BR]two") == "one\ntwo"
+    assert regEx.sub("\n", "one[BR]\ntwo") == "one\ntwo"
+    assert regEx.sub("\n", "one[BR]\n\ntwo") == "one\n\ntwo"
+
 
 @pytest.mark.core
 def testTextPatterns_ShortcodesValue():