Add test to ensure, that entities which expands to the XML fragments are parsed

Author: Mingun

tests/serde-de-references.rs

@@ -0,0 +1,59 @@
+use std::convert::Infallible;
+
+use quick_xml::de::{Deserializer, EntityResolver};
+use quick_xml::events::BytesText;
+use serde::Deserialize;
+
+struct TestResolver;
+impl EntityResolver for TestResolver {
+    type Error = Infallible;
+
+    fn capture(&mut self, _doctype: BytesText) -> Result<(), Self::Error> {
+        Ok(())
+    }
+    fn resolve(&self, entity: &str) -> Option<&str> {
+        match dbg!(entity) {
+            "text" => Some("&#x20;<![CDATA[second text]]>&#32;"),
+            _ => Some(
+                "
+                <child1 attribute = '&lt;attribute value&gt;'>&text;</child1>
+                <child2/>
+            ",
+            ),
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Deserialize)]
+struct Root {
+    child1: Child1,
+    child2: (),
+}
+
+#[derive(Debug, PartialEq, Deserialize)]
+struct Child1 {
+    #[serde(rename = "@attribute")]
+    attribute: String,
+
+    #[serde(rename = "$text")]
+    text: String,
+}
+
+#[test]
+fn entities() {
+    let mut de = Deserializer::from_str_with_resolver("<root>&entity;</root>", TestResolver);
+
+    let data = Root::deserialize(&mut de).unwrap();
+
+    assert!(de.is_empty(), "the whole XML document should be consumed");
+    assert_eq!(
+        data,
+        Root {
+            child1: Child1 {
+                attribute: "<attribute value>".to_string(),
+                text: " second text ".to_string(),
+            },
+            child2: (),
+        }
+    );
+}