test: add test cases for both #15 and #16

tests/issue_15_16.rs

@@ -0,0 +1,26 @@
+use orgize::Org;
+
+#[test]
+fn bad_headline_tags() {
+    contains_no_tag(Org::parse("* a ::"));
+
+    contains_no_tag(Org::parse("* a :(:"));
+
+    contains_one_tag(Org::parse("* a \t:_:"), "_");
+
+    contains_one_tag(Org::parse("* a \t :@:"), "@");
+
+    contains_one_tag(Org::parse("* a :#:"), "#");
+
+    contains_one_tag(Org::parse("* a\t :%:"), "%");
+
+    contains_one_tag(Org::parse("* a :余:"), "余");
+}
+
+fn contains_no_tag(org: Org) {
+    assert!(org.headlines().next().unwrap().title(&org).tags.is_empty());
+}
+
+fn contains_one_tag(org: Org, tag: &str) {
+    assert_eq!(vec![tag], org.headlines().next().unwrap().title(&org).tags);
+}