From a04c8dfbd7b4f45ffc07fbf457d30faa8c1e1b9d Mon Sep 17 00:00:00 2001
From: Naoki Ikeguchi <me@s6n.jp>
Date: Wed, 5 Nov 2025 22:18:18 +0900
Subject: [PATCH] feat(lsp): report progress while scanning the project (#7961)

---
 .changeset/clever-clocks-decide.md |  5 +++++
 Cargo.lock                         |  7 ++++--
 Cargo.toml                         |  1 +
 crates/biome_lsp/Cargo.toml        |  1 +
 crates/biome_lsp/src/session.rs    | 35 ++++++++++++++++++++++++++++++
 5 files changed, 47 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/clever-clocks-decide.md

diff --git a/.changeset/clever-clocks-decide.md b/.changeset/clever-clocks-decide.md
new file mode 100644
index 0000000000..e53cceb219
--- /dev/null
+++ b/.changeset/clever-clocks-decide.md
@@ -0,0 +1,5 @@
+---
+"@biomejs/biome": minor
+---
+
+The Biome Language Server now reports progress while scanning files and dependencies in the project.
diff --git a/Cargo.lock b/Cargo.lock
index 18a6f07f08..a880e97210 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1248,6 +1248,7 @@ dependencies = [
  "tower",
  "tower-lsp-server",
  "tracing",
+ "uuid",
 ]
 
 [[package]]
@@ -5641,11 +5642,13 @@ checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
 
 [[package]]
 name = "uuid"
-version = "1.15.1"
+version = "1.18.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e0f540e3240398cce6128b64ba83fdbdd86129c16a3aa1a3a252efd66eb3d587"
+checksum = "2f87b8aa10b915a06587d0dec516c282ff295b475d94abf425d62b57710070a2"
 dependencies = [
  "getrandom 0.3.2",
+ "js-sys",
+ "wasm-bindgen",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index bd1771db2b..b68e7f125c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -241,6 +241,7 @@ unicode-bom          = "2.0.3"
 unicode-width        = "0.1.12"
 ureq                 = "3.1.2"
 url                  = "2.5.7"
+uuid                 = "1.18.1"
 walkdir              = "2.5.0"
 web-time             = "1.1.0"
 windows              = "0.61.3"
diff --git a/crates/biome_lsp/Cargo.toml b/crates/biome_lsp/Cargo.toml
index 6415f9bbac..29bb44ddfd 100644
--- a/crates/biome_lsp/Cargo.toml
+++ b/crates/biome_lsp/Cargo.toml
@@ -37,6 +37,7 @@ serde_json           = { workspace = true }
 tokio                = { workspace = true, features = ["rt", "io-std"] }
 tower-lsp-server     = { workspace = true }
 tracing              = { workspace = true, features = ["attributes"] }
+uuid                 = { workspace = true, features = ["v4"] }
 
 [dev-dependencies]
 tokio = { workspace = true, features = ["rt", "rt-multi-thread", "macros"] }
diff --git a/crates/biome_lsp/src/session.rs b/crates/biome_lsp/src/session.rs
index 2cbc8b98d0..653f801510 100644
--- a/crates/biome_lsp/src/session.rs
+++ b/crates/biome_lsp/src/session.rs
@@ -47,6 +47,7 @@ use tower_lsp_server::lsp_types::{MessageType, Registration};
 use tower_lsp_server::lsp_types::{Unregistration, WorkspaceFolder};
 use tower_lsp_server::{Client, UriExt, lsp_types};
 use tracing::{debug, error, info, instrument, warn};
+use uuid::Uuid;
 
 pub(crate) struct ClientInformation {
     /// The name of the client
@@ -702,6 +703,36 @@ impl Session {
         scan_kind: ScanKind,
         force: bool,
     ) {
+        let progress_token = lsp_types::ProgressToken::String(Uuid::new_v4().to_string());
+        let is_work_done_progress_supported = self.initialize_params.get().is_some_and(|params| {
+            params
+                .client_capabilities
+                .window
+                .as_ref()
+                .is_some_and(|window| window.work_done_progress == Some(true))
+        });
+
+        // Let the user know the scanning is taking long time using the $/progress notification.
+        let progress = if is_work_done_progress_supported
+            && self
+                .client
+                .send_request::<lsp_types::request::WorkDoneProgressCreate>(
+                    lsp_types::WorkDoneProgressCreateParams {
+                        token: progress_token.clone(),
+                    },
+                )
+                .await
+                .is_ok()
+        {
+            let progress = self
+                .client
+                .progress(progress_token.clone(), "Biome is scanning the project");
+
+            Some(progress.begin().await)
+        } else {
+            None
+        };
+
         let session = self.clone();
 
         spawn_blocking(move || {
@@ -738,6 +769,10 @@ impl Session {
         })
         .await
         .unwrap();
+
+        if let Some(progress) = progress {
+            progress.finish().await;
+        }
     }
 
     #[tracing::instrument(level = "debug", skip(self))]