Add some tests

src/analyze.rs

@@ -1371,3 +1371,33 @@ impl Analyzer {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::testutil::testdata;
+
+    use super::*;
+
+    #[test]
+    fn test_analyze_smoke() {
+        let storage = Arc::new(Mutex::new(DocumentStorage::new()));
+        let mut analyzer = Analyzer::new(&storage);
+
+        let file = analyzer
+            .analyze(&testdata("workspaces/smoke/BUILD.gn"))
+            .unwrap();
+
+        // No parse error.
+        assert!(file
+            .ast_root
+            .statements
+            .iter()
+            .all(|s| !matches!(s, Statement::Unknown(_) | Statement::UnmatchedBrace(_))));
+
+        // Inspect the top-level scope.
+        let scope = file.scope_at(0);
+        assert!(scope.get("enable_opt").is_some());
+        assert!(scope.get("_lib").is_some());
+        assert!(scope.get("is_linux").is_some());
+    }
+}

src/client.rs

@@ -0,0 +1,52 @@
+// Copyright 2025 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::fmt::Display;
+
+use serde_json::Value;
+use tower_lsp::lsp_types::{ConfigurationItem, MessageType};
+
+use crate::providers::RpcResult;
+
+#[derive(Clone)]
+pub struct TestableClient {
+    client: Option<tower_lsp::Client>,
+}
+
+impl TestableClient {
+    pub fn new(client: tower_lsp::Client) -> Self {
+        Self {
+            client: Some(client),
+        }
+    }
+
+    #[cfg(test)]
+    pub fn new_for_testing() -> Self {
+        Self { client: None }
+    }
+
+    pub async fn log_message<M: Display>(&self, typ: MessageType, message: M) {
+        if let Some(client) = &self.client {
+            client.log_message(typ, message).await;
+        }
+    }
+
+    pub async fn configuration(&self, items: Vec<ConfigurationItem>) -> RpcResult<Vec<Value>> {
+        if let Some(client) = &self.client {
+            client.configuration(items).await
+        } else {
+            Ok(Vec::new())
+        }
+    }
+}

src/main.rs

@@ -15,10 +15,12 @@
 mod analyze;
 mod ast;
 mod builtins;
+mod client;
 mod config;
 mod providers;
 mod server;
 mod storage;
+mod testutil;
 mod util;
 
 #[tokio::main]

src/providers/hover.rs

@@ -172,3 +172,57 @@ pub async fn hover(context: &ProviderContext, params: HoverParams) -> RpcResult<
         range: Some(current_file.document.line_index.range(ident.span)),
     }))
 }
+
+#[cfg(test)]
+mod tests {
+    use tower_lsp::lsp_types::{
+        Position, Range, TextDocumentIdentifier, TextDocumentPositionParams, WorkDoneProgressParams,
+    };
+
+    use crate::testutil::testdata;
+
+    use super::*;
+
+    #[tokio::test]
+    async fn test_hover() {
+        let uri = Url::from_file_path(testdata("workspaces/hover/BUILD.gn")).unwrap();
+        let params = HoverParams {
+            text_document_position_params: TextDocumentPositionParams {
+                text_document: TextDocumentIdentifier { uri: uri.clone() },
+                position: Position {
+                    line: 17,
+                    character: 0,
+                },
+            },
+            work_done_progress_params: WorkDoneProgressParams::default(),
+        };
+
+        let response = hover(&ProviderContext::new_for_testing(), params)
+            .await
+            .unwrap();
+
+        assert_eq!(
+            response,
+            Some(Hover {
+                contents: HoverContents::Array(vec![
+                    MarkedString::from_language_code("gn".to_string(), "a = 1".to_string()),
+                    MarkedString::from_language_code("text".to_string(), "".to_string()),
+                    MarkedString::from_markdown(format!(
+                        "Defined at [//BUILD.gn:18:1]({}#L18,1)",
+                        uri
+                    )),
+                ]),
+                range: Some(Range {
+                    start: Position {
+                        line: 17,
+                        character: 0,
+                    },
+                    end: Position {
+                        line: 17,
+                        character: 1,
+                    },
+                }),
+            })
+        );
+    }
+}

src/providers/mod.rs

@@ -17,11 +17,12 @@ use std::{
     sync::{Arc, Mutex},
 };
 
-use tower_lsp::{lsp_types::Position, Client};
+use tower_lsp::lsp_types::Position;
 
 use crate::{
     analyze::{AnalyzedFile, Analyzer},
     ast::{Identifier, Node},
+    client::TestableClient,
     storage::DocumentStorage,
 };
 
@@ -39,7 +40,20 @@ pub type RpcResult<T> = tower_lsp::jsonrpc::Result<T>;
 pub struct ProviderContext {
     pub storage: Arc<Mutex<DocumentStorage>>,
     pub analyzer: Arc<Mutex<Analyzer>>,
-    pub client: Client,
+    pub client: TestableClient,
+}
+
+impl ProviderContext {
+    #[cfg(test)]
+    pub fn new_for_testing() -> Self {
+        let storage = Arc::new(Mutex::new(DocumentStorage::new()));
+        let analyzer = Arc::new(Mutex::new(Analyzer::new(&storage)));
+        Self {
+            storage,
+            analyzer,
+            client: TestableClient::new_for_testing(),
+        }
+    }
 }
 
 pub fn into_rpc_error(err: std::io::Error) -> tower_lsp::jsonrpc::Error {

src/server.rs

@@ -29,11 +29,12 @@ use tower_lsp::{
         HoverProviderCapability, InitializeParams, InitializeResult, InitializedParams,
         MessageType, OneOf, ServerCapabilities, TextDocumentSyncCapability, TextDocumentSyncKind,
     },
-    Client, LanguageServer, LspService, Server,
+    LanguageServer, LspService, Server,
 };
 
 use crate::{
     analyze::{find_workspace_root, Analyzer},
+    client::TestableClient,
     config::Configurations,
     providers::{ProviderContext, RpcResult},
     storage::DocumentStorage,
@@ -48,7 +49,7 @@ impl Backend {
     pub fn new(
         storage: &Arc<Mutex<DocumentStorage>>,
         analyzer: &Arc<Mutex<Analyzer>>,
-        client: Client,
+        client: TestableClient,
     ) -> Self {
         Self {
             context: ProviderContext {
@@ -180,8 +181,9 @@ impl LanguageServer for Backend {
 pub async fn run() {
     let storage = Arc::new(Mutex::new(DocumentStorage::new()));
     let analyzer = Arc::new(Mutex::new(Analyzer::new(&storage)));
-    let (service, socket) =
-        LspService::new(move |client| Backend::new(&storage, &analyzer, client));
+    let (service, socket) = LspService::new(move |client| {
+        Backend::new(&storage, &analyzer, TestableClient::new(client))
+    });
 
     let stdin = tokio::io::stdin();
     let stdout = tokio::io::stdout();

src/testutil.rs

@@ -0,0 +1,24 @@
+// Copyright 2025 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![cfg(test)]
+
+use std::path::{Path, PathBuf};
+
+pub fn testdata(name: impl AsRef<Path>) -> PathBuf {
+    let mut path = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    path.push("testdata");
+    path.push(name.as_ref());
+    path
+}

testdata/workspaces/hover/.gn

@@ -0,0 +1,15 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+buildconfig = "//BUILDCONFIG.gn"

testdata/workspaces/hover/BUILD.gn

@@ -0,0 +1,36 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Avoid attaching the copyright comment to the first assignment.
+start = true
+
+a = 1
+
+b = 1
+b = 2
+b = 3
+
+template("foo") {
+}
+
+if (true) {
+  template("bar") {
+  }
+} else {
+  template("bar") {
+  }
+}
+
+foo("foo")
+bar("bar")

testdata/workspaces/hover/BUILDCONFIG.gn

@@ -0,0 +1,13 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.

testdata/workspaces/smoke/.gn

@@ -0,0 +1,15 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+buildconfig = "//BUILDCONFIG.gn"

testdata/workspaces/smoke/BUILD.gn

@@ -0,0 +1,47 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+declare_args() {
+  enable_opt = false
+}
+
+static_library("lib") {
+  sources = [ "lib.cc" ]
+  opt = enable_opt
+}
+
+if (is_linux) {
+  static_library("lib_linux") {
+    sources = [ "lib_linux.cc" ]
+    opt = enable_opt
+  }
+  _lib = ":lib_linux"
+} else if (is_win) {
+  static_library("lib_win") {
+    sources = [ "lib_win.cc" ]
+    opt = enable_opt
+  }
+  _lib = ":lib_win"
+} else {
+  assert(false, "Unsupported platform")
+}
+
+executable("main") {
+  sources = [ "main.cc" ]
+  deps = [
+    ":lib",
+    _lib,
+  ]
+  opt = enable_opt
+}

testdata/workspaces/smoke/BUILDCONFIG.gn

@@ -0,0 +1,15 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+is_linux = current_os == "linux"