Introduce ApiInfo::into_parts method

We already support creating an ApiInfo object from its constituent
parts. It is only consequent to be able to destructure such an object in
an analogous way. To that end, this change introduce the
ApiInfo::into_parts methods.

CHANGELOG.md

@@ -3,6 +3,7 @@ Unreleased
 - Renamed `data::v2::bars::BarReq` to `BarsReq`
   - Deprecated `data::v2::bars::BarReq`
 - Introduced `data::v2::bars::BarsReqInit` type
+- Introduced `ApiInfo::into_parts` method
 
 
 0.22.4

src/api_info.rs

@@ -1,4 +1,4 @@
-// Copyright (C) 2019-2021 The apca Developers
+// Copyright (C) 2019-2022 The apca Developers
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 use std::env::var_os;
@@ -87,4 +87,41 @@ impl ApiInfo {
       secret,
     })
   }
+
+  /// Split this `ApiInfo` object back into its constituent parts.
+  ///
+  /// This method is the inverse of the [`from_parts`][Self::from_parts]
+  /// constructor. It returns a tuple comprising the base URL, key ID,
+  /// and secret.
+  pub fn into_parts(self) -> (String, String, String) {
+    let ApiInfo {
+      base_url,
+      key_id,
+      secret,
+    } = self;
+    (base_url.into(), key_id, secret)
+  }
+}
+
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+
+  /// Check that we can create an [`ApiInfo`] object from its
+  /// constituent parts and destructure it back into them.
+  #[test]
+  fn from_into_parts() {
+    let base_url = "https://paper-api.alpaca.markets/";
+    let key_id = "XXXXXXXXXXXXXXXXXXXX";
+    let secret = "YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY";
+
+    let api_info = ApiInfo::from_parts(base_url, key_id, secret).unwrap();
+    let (new_base_url, new_key_id, new_secret) = api_info.into_parts();
+
+    assert_eq!(new_base_url, base_url);
+    assert_eq!(new_key_id, key_id);
+    assert_eq!(new_secret, secret);
+  }
 }