Markdown: Fix UTF8 chars breaking elements (#366)

* failing test for splitSpaceLeft and splitSpaceRight

* fix splitSpaceLeft and splitSpaceRight

Author: nlepage

claat/parser/trim.go

@@ -161,7 +161,7 @@ func splitSpaceLeft(s string) (v string, sp string) {
 			return s[i:], s[:i]
 		}
 	}
-	return s, ""
+	return "", s
 }
 
 func splitSpaceRight(s string) (v string, sp string) {
@@ -171,7 +171,7 @@ func splitSpaceRight(s string) (v string, sp string) {
 			return string(rs[:i+1]), string(rs[i+1:])
 		}
 	}
-	return string(rs), ""
+	return "", string(rs)
 }
 
 func requiresSpacer(a, b types.Node) bool {

claat/parser/trim_test.go

@@ -0,0 +1,53 @@
+package parser
+
+import "testing"
+
+type testCase struct {
+	s  string
+	v  string
+	sp string
+}
+
+func TestSplitSpaceLeft(t *testing.T) {
+	testCases := []testCase{
+		{"basic test case", "basic test case", ""},
+		{"  some space  ", "some space  ", "  "},
+		{"\t\n\rsome less common spaces", "some less common spaces", "\t\n\r"},
+		{" 🙂 a smiley space ", "🙂 a smiley space ", " "},
+		{"       ", "", "       "},
+		{"", "", ""},
+		{"       x", "x", "       "},
+	}
+
+	for _, tc := range testCases {
+		v, sp := splitSpaceLeft(tc.s)
+		if v != tc.v {
+			t.Errorf("v=%#v, expected %#v, (s=%#v)", v, tc.v, tc.s)
+		}
+		if sp != tc.sp {
+			t.Errorf("sp=%#v, expected %#v, (s=%#v)", sp, tc.sp, tc.s)
+		}
+	}
+}
+
+func TestSplitSpaceRight(t *testing.T) {
+	testCases := []testCase{
+		{"basic test case", "basic test case", ""},
+		{"  some space  ", "  some space", "  "},
+		{"some less common spaces\t\n\r", "some less common spaces", "\t\n\r"},
+		{" 🙂 a smiley space ", " 🙂 a smiley space", " "},
+		{"       ", "", "       "},
+		{"", "", ""},
+		{"x       ", "x", "       "},
+	}
+
+	for _, tc := range testCases {
+		v, sp := splitSpaceRight(tc.s)
+		if v != tc.v {
+			t.Errorf("v=%#v, expected %#v, (s=%#v)", v, tc.v, tc.s)
+		}
+		if sp != tc.sp {
+			t.Errorf("sp=%#v, expected %#v, (s=%#v)", sp, tc.sp, tc.s)
+		}
+	}
+}