From 4be8e5a372791a88b8f18a36155b9d34c9b2492d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Ml=C3=A1dek?= <david.mladek.cz@gmail.com>
Date: Tue, 28 May 2024 20:34:51 +0200
Subject: [PATCH] add `FlycheckStatus` to global state

---
 .../crates/rust-analyzer/src/global_state.rs  | 21 +++++++++++++++++--
 .../crates/rust-analyzer/src/main_loop.rs     | 20 +++++++++++++-----
 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/src/tools/rust-analyzer/crates/rust-analyzer/src/global_state.rs b/src/tools/rust-analyzer/crates/rust-analyzer/src/global_state.rs
index 0c2e60fcc91..1216de2de41 100644
--- a/src/tools/rust-analyzer/crates/rust-analyzer/src/global_state.rs
+++ b/src/tools/rust-analyzer/crates/rust-analyzer/src/global_state.rs
@@ -87,7 +87,7 @@ pub(crate) struct GlobalState {
     pub(crate) flycheck_sender: Sender<flycheck::Message>,
     pub(crate) flycheck_receiver: Receiver<flycheck::Message>,
     pub(crate) last_flycheck_error: Option<String>,
-    pub(crate) diagnostics_received: FxHashMap<usize, bool>,
+    pub(crate) flycheck_status: FxHashMap<usize, FlycheckStatus>,
 
     // Test explorer
     pub(crate) test_run_session: Option<Vec<flycheck::CargoTestHandle>>,
@@ -166,6 +166,14 @@ pub(crate) struct GlobalStateSnapshot {
     pub(crate) flycheck: Arc<[FlycheckHandle]>,
 }
 
+#[derive(Debug, Clone)]
+pub(crate) enum FlycheckStatus {
+    Unknown,
+    Started,
+    DiagnosticReceived,
+    Finished,
+}
+
 impl std::panic::UnwindSafe for GlobalStateSnapshot {}
 
 impl GlobalState {
@@ -225,7 +233,7 @@ impl GlobalState {
             flycheck_sender,
             flycheck_receiver,
             last_flycheck_error: None,
-            diagnostics_received: FxHashMap::default(),
+            flycheck_status: FxHashMap::default(),
 
             test_run_session: None,
             test_run_sender,
@@ -513,3 +521,12 @@ pub(crate) fn url_to_file_id(vfs: &vfs::Vfs, url: &Url) -> anyhow::Result<FileId
     let res = vfs.file_id(&path).ok_or_else(|| anyhow::format_err!("file not found: {path}"))?;
     Ok(res)
 }
+
+impl FlycheckStatus {
+    pub(crate) fn should_clear_old_diagnostics(&self) -> bool {
+        match self {
+            FlycheckStatus::Unknown | FlycheckStatus::Started => false,
+            FlycheckStatus::DiagnosticReceived | FlycheckStatus::Finished => true,
+        }
+    }
+}
diff --git a/src/tools/rust-analyzer/crates/rust-analyzer/src/main_loop.rs b/src/tools/rust-analyzer/crates/rust-analyzer/src/main_loop.rs
index a94ca871bdd..efedea77fef 100644
--- a/src/tools/rust-analyzer/crates/rust-analyzer/src/main_loop.rs
+++ b/src/tools/rust-analyzer/crates/rust-analyzer/src/main_loop.rs
@@ -19,7 +19,7 @@ use crate::{
     config::Config,
     diagnostics::fetch_native_diagnostics,
     dispatch::{NotificationDispatcher, RequestDispatcher},
-    global_state::{file_id_to_url, url_to_file_id, GlobalState},
+    global_state::{file_id_to_url, url_to_file_id, FlycheckStatus, GlobalState},
     hack_recover_crate_name,
     lsp::{
         from_proto, to_proto,
@@ -804,10 +804,13 @@ impl GlobalState {
     fn handle_flycheck_msg(&mut self, message: flycheck::Message) {
         match message {
             flycheck::Message::AddDiagnostic { id, workspace_root, diagnostic } => {
-                if !self.diagnostics_received.get(&id).copied().unwrap_or_default() {
+                let flycheck_status =
+                    self.flycheck_status.entry(id).or_insert(FlycheckStatus::Unknown);
+
+                if !flycheck_status.should_clear_old_diagnostics() {
                     self.diagnostics.clear_check(id);
-                    self.diagnostics_received.insert(id, true);
                 }
+                *flycheck_status = FlycheckStatus::DiagnosticReceived;
                 let snap = self.snapshot();
                 let diagnostics = crate::diagnostics::to_proto::map_rust_diagnostic_to_lsp(
                     &self.config.diagnostics_map(),
@@ -836,25 +839,32 @@ impl GlobalState {
             flycheck::Message::Progress { id, progress } => {
                 let (state, message) = match progress {
                     flycheck::Progress::DidStart => {
-                        self.diagnostics_received.insert(id, false);
+                        self.flycheck_status.insert(id, FlycheckStatus::Started);
                         (Progress::Begin, None)
                     }
                     flycheck::Progress::DidCheckCrate(target) => (Progress::Report, Some(target)),
                     flycheck::Progress::DidCancel => {
                         self.last_flycheck_error = None;
+                        // We do not clear
+                        self.flycheck_status.insert(id, FlycheckStatus::Finished);
                         (Progress::End, None)
                     }
                     flycheck::Progress::DidFailToRestart(err) => {
                         self.last_flycheck_error =
                             Some(format!("cargo check failed to start: {err}"));
+                        self.flycheck_status.insert(id, FlycheckStatus::Finished);
                         return;
                     }
                     flycheck::Progress::DidFinish(result) => {
                         self.last_flycheck_error =
                             result.err().map(|err| format!("cargo check failed to start: {err}"));
-                        if !self.diagnostics_received.get(&id).copied().unwrap_or_default() {
+                        let flycheck_status =
+                            self.flycheck_status.entry(id).or_insert(FlycheckStatus::Unknown);
+
+                        if !flycheck_status.should_clear_old_diagnostics() {
                             self.diagnostics.clear_check(id);
                         }
+                        *flycheck_status = FlycheckStatus::Finished;
                         (Progress::End, None)
                     }
                 };