[ISSUE-188] Add jlink script file support via set_script_file() (#210)

Adds support to specify a script file via `set_script_file()` as detailed
in ISSUE-188.

pylink/jlink.py

@@ -830,6 +830,27 @@ def set_log_file(self, file_path):
         if res:
             raise errors.JLinkException(res)
 
+    @open_required
+    def set_script_file(self, file_path):
+        """Sets the custom `Script File`_ to use.
+
+        Args:
+          self (JLink): the ``JLink`` instance
+          file_path (str): file path to the JLink script file to be used
+
+        Returns:
+          ``None``
+
+        Raises:
+          JLinkException: if the path specified is invalid.
+
+        .. _Script File:
+          https://wiki.segger.com/J-Link_script_files
+        """
+        res = self.exec_command('scriptfile = %s' % file_path)
+        if res:
+            raise errors.JLinkException('Failed to set JLink Script File: %r' % file_path)
+
     @open_required
     def invalidate_firmware(self):
         """Invalidates the emulator's firmware.

tests/unit/test_jlink.py

@@ -6260,6 +6260,36 @@ def test_set_log_file_raises_exception_if_SetLogFile_fails(self):
         with self.assertRaises(JLinkException):
             self.jlink.set_log_file('my/file/path')
 
+    def test_set_script_file_success(self):
+        """Tests that set_script_file uses provided parameters.
+
+        Args:
+          self (TestJLink): the ``TestJLink`` instance
+
+        Returns:
+          ``None``
+        """
+        args = ['my/file/path']
+        expected = ['scriptfile = my/file/path']
+        self.jlink.exec_command = mock.Mock()
+        self.jlink.exec_command.return_value = 0
+
+        self.jlink.set_script_file(*args)
+        self.jlink.exec_command.assert_called_once_with(*expected)
+
+    def test_set_script_file_raises_exception_if_exec_command_fails(self):
+        """Tests that set_script_file raises a JLinkException on failure.
+        Args:
+          self (TestJLink): the ``TestJLink`` instance
+
+        Returns:
+          ``None``
+        """
+        self.jlink.exec_command = mock.Mock()
+        self.jlink.exec_command.return_value = -1
+        with self.assertRaises(JLinkException):
+            self.jlink.set_script_file('my/file/path')
+
 
 if __name__ == '__main__':
     unittest.main()