1 files changed, 86 insertions, 0 deletions
diff --git a/third_party/rust/fluent-bundle/src/errors.rs b/third_party/rust/fluent-bundle/src/errors.rs
new file mode 100644
index 0000000000..ec4a02c4b4
--- /dev/null
+++ b/third_party/rust/fluent-bundle/src/errors.rs
@@ -0,0 +1,86 @@
+use crate::resolver::ResolverError;
+use fluent_syntax::parser::ParserError;
+use std::error::Error;
+
+#[derive(Debug, PartialEq, Clone)]
+pub enum EntryKind {
+    Message,
+    Term,
+    Function,
+}
+
+impl std::fmt::Display for EntryKind {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Message => f.write_str("message"),
+            Self::Term => f.write_str("term"),
+            Self::Function => f.write_str("function"),
+        }
+    }
+}
+
+/// Core error type for Fluent runtime system.
+///
+/// It contains three main types of errors that may come up
+/// during runtime use of the fluent-bundle crate.
+#[derive(Debug, PartialEq, Clone)]
+pub enum FluentError {
+    /// An error which occurs when
+    /// [`FluentBundle::add_resource`](crate::bundle::FluentBundle::add_resource)
+    /// adds entries that are already registered in a given [`FluentBundle`](crate::FluentBundle).
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use fluent_bundle::{FluentBundle, FluentResource};
+    /// use unic_langid::langid;
+    ///
+    /// let ftl_string = String::from("intro = Welcome, { $name }.");
+    /// let res1 = FluentResource::try_new(ftl_string)
+    ///     .expect("Could not parse an FTL string.");
+    ///
+    /// let ftl_string = String::from("intro = Hi, { $name }.");
+    /// let res2 = FluentResource::try_new(ftl_string)
+    ///     .expect("Could not parse an FTL string.");
+    ///
+    /// let langid_en = langid!("en-US");
+    /// let mut bundle = FluentBundle::new(vec![langid_en]);
+    ///
+    /// bundle.add_resource(&res1)
+    ///     .expect("Failed to add FTL resources to the bundle.");
+    ///
+    /// assert!(bundle.add_resource(&res2).is_err());
+    /// ```
+    Overriding {
+        kind: EntryKind,
+        id: String,
+    },
+    ParserError(ParserError),
+    ResolverError(ResolverError),
+}
+
+impl std::fmt::Display for FluentError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Overriding { kind, id } => {
+                write!(f, "Attempt to override an existing {}: \"{}\".", kind, id)
+            }
+            Self::ParserError(err) => write!(f, "Parser error: {}", err),
+            Self::ResolverError(err) => write!(f, "Resolver error: {}", err),
+        }
+    }
+}
+
+impl Error for FluentError {}
+
+impl From<ResolverError> for FluentError {
+    fn from(error: ResolverError) -> Self {
+        Self::ResolverError(error)
+    }
+}
+
+impl From<ParserError> for FluentError {
+    fn from(error: ParserError) -> Self {
+        Self::ParserError(error)
+    }
+}