[FEATURE] Add join and strip string functions to scripting

src/ytdl_sub/script/functions/string_functions.py

@@ -176,3 +176,40 @@ class StringFunctions:
            # World
         """
         return String(string.value.encode("utf-8").decode("unicode_escape"))
+
+    @staticmethod
+    def join(separator: String, array: Array) -> String:
+        """
+        :description:
+            Join all elements in the array together as a string, and insert the separator between them.
+
+        :usage:
+
+        .. code-block:: python
+
+           {
+             %join( ", ", ["item1", "item2"] )
+           }
+
+           # "item1, item2"
+        """
+
+        return String(separator.value.join(str(val) for val in array.value))
+
+    @staticmethod
+    def strip(string: String) -> String:
+        """
+        :description:
+            Strip a string of all its whitespace at the beginning and end.
+
+        :usage:
+
+        .. code-block:: python
+
+           {
+             %trim(" delete the outer! ")
+           }
+
+           # "delete the outer!"
+        """
+        return String(string.value.strip())

tests/unit/script/functions/test_string_functions.py

@@ -152,3 +152,19 @@ class TestNumericFunctions:
             output = single_variable_output(f"{{%split('{input_string}', {split})}}")
 
         assert output == expected_output
+
+    @pytest.mark.parametrize(
+        "value, expected_output",
+        [("['a', 'b', 'c']", 'a, b, c'), ("['nope', [], {}]", 'nope, [], {}'), ("['a', 1, 3.14, True]", 'a, 1, 3.14, true')],
+    )
+    def test_join(self, value, expected_output):
+        output = single_variable_output(f"{{%join(', ', {value})}}")
+        assert output == expected_output
+
+    @pytest.mark.parametrize(
+        "value, expected_output",
+        [(" delete outer ", 'delete outer'), (" delete me\n\n", 'delete me')],
+    )
+    def test_strip(self, value, expected_output):
+        output = single_variable_output(f"{{%strip('{value}')}}")
+        assert output == expected_output