Rewrite From/TryFrom conversions on generated types to avoid future orphan rule violations (#34554)

* script: Add traits to allow converting between types that are not defined in the script crate.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* script: Rewrite all From/TryFrom implementations on generated WebIDL types to use new Convert/TryConvert traits.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

---------

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

1 files changed, 21 insertions, 0 deletions

diff --git a/components/script/conversions.rs b/components/script/conversions.rs
new file mode 100644
index 00000000000..01186119ff5
--- /dev/null
+++ b/components/script/conversions.rs
@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+/// A version of the Into<T> trait from the standard library that can be used
+/// to convert between two types that are not defined in the script crate.
+/// This is intended to be used on dict/enum types generated from WebIDL once
+/// those types are moved out of the script crate.
+pub trait Convert<T> {
+    fn convert(self) -> T;
+}
+
+/// A version of the TryInto<T> trait from the standard library that can be used
+/// to convert between two types that are not defined in the script crate.
+/// This is intended to be used on dict/enum types generated from WebIDL once
+/// those types are moved out of the script crate.
+pub trait TryConvert<T> {
+    type Error;
+
+    fn try_convert(self) -> Result<T, Self::Error>;
+}