Implement LSP Text Document Synchronization

crates/nu-lsp/Cargo.toml

@@ -14,8 +14,9 @@ nu-protocol = { path = "../nu-protocol", version = "0.87.0" }
 
 reedline = { version = "0.26" }
 
+crossbeam-channel = "0.5.8"
 lsp-types = "0.94.1"
-lsp-server = "0.7.4"
+lsp-server = { version = "0.7.4", git = "https://github.com/schrieveslaach/rust-analyzer.git", branch = "cancelable-initialization" }
 miette = "5.10"
 ropey = "1.6.1"
 serde = "1.0"

crates/nu-lsp/src/diagnostics.rs

@@ -0,0 +1,147 @@
+use lsp_types::{
+    notification::{Notification, PublishDiagnostics},
+    Diagnostic, DiagnosticSeverity, PublishDiagnosticsParams, Url,
+};
+use miette::{IntoDiagnostic, Result};
+use nu_parser::parse;
+use nu_protocol::{
+    engine::{EngineState, StateWorkingSet},
+    eval_const::create_nu_constant,
+    Span, Value, NU_VARIABLE_ID,
+};
+
+use crate::LanguageServer;
+
+impl LanguageServer {
+    pub(crate) fn publish_diagnostics_for_file(
+        &self,
+        uri: Url,
+        engine_state: &mut EngineState,
+    ) -> Result<()> {
+        let cwd = std::env::current_dir().expect("Could not get current working directory.");
+        engine_state.add_env_var("PWD".into(), Value::test_string(cwd.to_string_lossy()));
+
+        let Ok(nu_const) = create_nu_constant(engine_state, Span::unknown()) else {
+            return Ok(());
+        };
+        engine_state.set_variable_const_val(NU_VARIABLE_ID, nu_const);
+
+        let mut working_set = StateWorkingSet::new(engine_state);
+
+        let Some((rope_of_file, file_path)) = self.rope(&uri) else {
+            return Ok(());
+        };
+
+        let contents = rope_of_file.bytes().collect::<Vec<u8>>();
+        let offset = working_set.next_span_start();
+        parse(
+            &mut working_set,
+            Some(&file_path.to_string_lossy()),
+            &contents,
+            false,
+        );
+
+        let mut diagnostics = PublishDiagnosticsParams {
+            uri,
+            diagnostics: Vec::new(),
+            version: None,
+        };
+
+        for err in working_set.parse_errors.iter() {
+            let message = err.to_string();
+
+            diagnostics.diagnostics.push(Diagnostic {
+                range: Self::span_to_range(&err.span(), rope_of_file, offset),
+                severity: Some(DiagnosticSeverity::ERROR),
+                message,
+                ..Default::default()
+            });
+        }
+
+        self.connection
+            .sender
+            .send(lsp_server::Message::Notification(
+                lsp_server::Notification::new(PublishDiagnostics::METHOD.to_string(), diagnostics),
+            ))
+            .into_diagnostic()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use assert_json_diff::assert_json_eq;
+    use lsp_types::Url;
+    use nu_test_support::fs::fixtures;
+
+    use crate::tests::{initialize_language_server, open, update};
+
+    #[test]
+    fn publish_diagnostics_variable_does_not_exists() {
+        let (client_connection, _recv) = initialize_language_server();
+
+        let mut script = fixtures();
+        script.push("lsp");
+        script.push("diagnostics");
+        script.push("var.nu");
+        let script = Url::from_file_path(script).unwrap();
+
+        let notification = open(&client_connection, script.clone());
+
+        assert_json_eq!(
+            notification,
+            serde_json::json!({
+                "method": "textDocument/publishDiagnostics",
+                "params": {
+                    "uri": script,
+                    "diagnostics": [{
+                        "range": {
+                            "start": { "line": 0, "character": 6 },
+                            "end": { "line": 0, "character": 30 }
+                        },
+                        "message": "Variable not found.",
+                        "severity": 1
+                    }]
+                }
+            })
+        );
+    }
+
+    #[test]
+    fn publish_diagnostics_fixed_unknown_variable() {
+        let (client_connection, _recv) = initialize_language_server();
+
+        let mut script = fixtures();
+        script.push("lsp");
+        script.push("diagnostics");
+        script.push("var.nu");
+        let script = Url::from_file_path(script).unwrap();
+
+        open(&client_connection, script.clone());
+        let notification = update(
+            &client_connection,
+            script.clone(),
+            String::from("$env"),
+            Some(lsp_types::Range {
+                start: lsp_types::Position {
+                    line: 0,
+                    character: 6,
+                },
+                end: lsp_types::Position {
+                    line: 0,
+                    character: 30,
+                },
+            }),
+        );
+
+        assert_json_eq!(
+            notification,
+            serde_json::json!({
+                "method": "textDocument/publishDiagnostics",
+                "params": {
+                    "uri": script,
+                    "diagnostics": []
+                }
+            })
+        );
+    }
+}