Implement surrogate pairs

picojson/examples/test_surrogate_pairs.rs

@@ -0,0 +1,69 @@
+use picojson::{Event, PullParser, SliceParser};
+
+fn main() {
+    // Test the original failing case: ["\uD801\udc37"]
+    let json = r#"["\uD801\udc37"]"#;
+    let mut buffer = [0u8; 1024];
+    let mut parser = SliceParser::with_buffer(json, &mut buffer);
+
+    let mut string_found = false;
+    let mut string_bytes = Vec::new();
+
+    loop {
+        match parser.next_event() {
+            Ok(Event::EndDocument) => break,
+            Ok(Event::String(s)) => {
+                string_found = true;
+                string_bytes = s.as_bytes().to_vec();
+                println!("Found string: {:?}", s);
+                println!("String content as bytes: {:?}", string_bytes);
+            }
+            Ok(event) => {
+                println!("Event: {:?}", event);
+            }
+            Err(e) => panic!("Parser error: {:?}", e),
+        }
+    }
+
+    println!("Successfully parsed surrogate pair JSON");
+
+    // The string should be decoded to U+10437 which is encoded as UTF-8: [0xF0, 0x90, 0x90, 0xB7]
+    if string_found {
+        assert_eq!(
+            string_bytes,
+            vec![0xF0, 0x90, 0x90, 0xB7],
+            "Surrogate pair should decode to U+10437"
+        );
+        println!("✅ Surrogate pair correctly decoded!");
+    } else {
+        panic!("Expected String event not found");
+    }
+
+    // Test additional surrogate pairs
+    let test_cases = vec![
+        (r#"["\uD834\uDD1E"]"#, "Musical G clef symbol"),
+        (r#"["\uD83D\uDE00"]"#, "Grinning face emoji"),
+    ];
+
+    for (json, description) in test_cases {
+        println!("\nTesting {}: {}", description, json);
+        let mut buffer = [0u8; 1024];
+        let mut parser = SliceParser::with_buffer(json, &mut buffer);
+
+        let mut success = false;
+        loop {
+            match parser.next_event() {
+                Ok(Event::EndDocument) => break,
+                Ok(Event::String(_)) => success = true,
+                Ok(_) => {}
+                Err(e) => panic!("Parser error for {}: {:?}", description, e),
+            }
+        }
+
+        if success {
+            println!("✅ Successfully parsed {}", description);
+        } else {
+            panic!("Failed to find string in {}", description);
+        }
+    }
+}