Append the label value of the primary spans of diagnostics to the LSP diagnostics message if it is available.

src/actions/compiler_message_parsing.rs

@@ -105,7 +105,13 @@ pub fn parse(message: &str) -> Result<FileDiagnostic, ParseError> {
             None => String::new(),
         })),
         source: Some("rustc".into()),
-        message: message.message,
+        message: {
+            if let Some(label) = primary.label {
+                format!("{}\n{}", message.message, label)
+            } else {
+                message.message
+            }
+        },
     };
 
     Ok(FileDiagnostic {

src/test/mod.rs

@@ -204,7 +204,26 @@ fn test_borrow_error() {
                ls_server::ServerStateChange::Continue);
     expect_messages(results.clone(), &[ExpectedMessage::new(Some(0)).expect_contains("capabilities"),
                                        ExpectedMessage::new(None).expect_contains("diagnosticsBegin"),
-                                       ExpectedMessage::new(None).expect_contains(r#""message":"cannot borrow `x` as mutable more than once at a time""#),
+                                       ExpectedMessage::new(None).expect_contains(r#""message":"cannot borrow `x` as mutable more than once at a time\nsecond mutable borrow occurs here""#),
+                                       ExpectedMessage::new(None).expect_contains("diagnosticsEnd")]);
+}
+
+#[test]
+fn test_mismatched_types() {
+    let (cache, _tc) = init_env("mismatched_types");
+
+    let root_path = cache.abs_path(Path::new("."));
+    let messages = vec![
+        ServerMessage::initialize(0, root_path.as_os_str().to_str().map(|x| x.to_owned()))
+    ];
+
+    let (mut server, results) = mock_server(messages);
+    // Initialise and build.
+    assert_eq!(ls_server::LsService::handle_message(&mut server),
+               ls_server::ServerStateChange::Continue);
+    expect_messages(results.clone(), &[ExpectedMessage::new(Some(0)).expect_contains("capabilities"),
+                                       ExpectedMessage::new(None).expect_contains("diagnosticsBegin"),
+                                       ExpectedMessage::new(None).expect_contains(r#""message":"mismatched types\nexpected u32, found &str""#),
                                        ExpectedMessage::new(None).expect_contains("diagnosticsEnd")]);
 }
 

test_data/mismatched_types/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "mismatched_types"
+version = "0.1.0"
+authors = ["Nelson Chen <crazysim@gmail.com>"]
+
+[dependencies]

test_data/mismatched_types/src/main.rs

@@ -0,0 +1,8 @@
+fn main() {
+    let a_string = "hoop";
+    u32_only(a_string);
+}
+
+fn u32_only(i: u32) -> u32 {
+    i
+}