feat: textDocument/inlayHint

Cargo.toml

@@ -11,5 +11,5 @@ lsp-textdocument = { git = "https://github.com/GiveMe-A-Name/lsp-textdocument.gi
 mktemp = "0.5"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-tokio = { version = "1.32.0", features = ["fs", "io-std", "macros", "process", "rt-multi-thread"] }
+tokio = { version = "1.32.0", features = ["fs", "io-std", "macros", "process", "rt-multi-thread", "time"] }
 tower-lsp = "0.20.0"

README.md

@@ -39,10 +39,10 @@ Language Server Protocol implementation for nushell
 - [x] [textDocument/didChange](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_didChange),
       [textDocument/didClose](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_didClose),
       and [textDocument/didOpen](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_didOpen)
+- [x] [textDocument/inlayHint](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_inlayHint) -> `nu --ide-check`
 - [x] [textDocument/publishDiagnostics](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_publishDiagnostics) -> `nu --ide-check`
 - [x] [workspace/configuration](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_configuration)
 - [x] [workspace/didChangeConfiguration](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_didChangeConfiguration)
-- [ ] [textDocument/inlayHint](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_inlayHint) -> `nu --ide-check`
 - [ ] raise a PR for `vscode-nushell-lang` to replace its wrapper/glue code with `nuls`
 
 ### stretch goals

src/backend/language_server.rs

@@ -105,12 +105,15 @@ impl LanguageServer for Backend {
 
         Ok(InitializeResult {
             capabilities: ServerCapabilities {
-                // `nu --ide-complete`
                 completion_provider: Some(CompletionOptions::default()),
-                // `nu --ide-goto-def`
                 definition_provider: Some(OneOf::Left(true)),
-                // `nu --ide-hover`
                 hover_provider: Some(HoverProviderCapability::Simple(true)),
+                inlay_hint_provider: Some(OneOf::Right(InlayHintServerCapabilities::Options(
+                    InlayHintOptions {
+                        resolve_provider: Some(false),
+                        ..Default::default()
+                    },
+                ))),
                 // TODO: what do we do when the client doesn't support UTF-16 ?
                 // lsp-textdocument crate requires UTF-16
                 position_encoding: Some(PositionEncodingKind::UTF16),
@@ -286,4 +289,13 @@ impl LanguageServer for Backend {
             range,
         }))
     }
+
+    async fn inlay_hint(&self, params: InlayHintParams) -> Result<Option<Vec<InlayHint>>> {
+        let document_inlay_hints = self.document_inlay_hints.read().map_err(|e| {
+            tower_lsp::jsonrpc::Error::invalid_params(format!(
+                "cannot read from inlay hints cache: {e:?}"
+            ))
+        })?;
+        Ok(document_inlay_hints.get(&params.text_document.uri).cloned())
+    }
 }

src/backend/mod.rs

@@ -4,9 +4,10 @@ use std::time::{Duration, Instant};
 use std::{ffi::OsStr, sync::RwLock};
 
 pub(crate) mod language_server;
+use crate::nu::{IdeCheckHint, IdeCheckResponse};
 use crate::{
     error::map_err_to_internal_error,
-    nu::{run_compiler, IdeCheck, IdeCheckDiagnostic, IdeSettings},
+    nu::{run_compiler, IdeCheckDiagnostic, IdeSettings},
 };
 use lsp_textdocument::{FullTextDocument, TextDocuments};
 
@@ -25,6 +26,7 @@ pub(crate) struct Backend {
     can_publish_diagnostics: OnceLock<bool>,
     client: Client,
     documents: RwLock<TextDocuments>,
+    document_inlay_hints: RwLock<HashMap<Url, Vec<InlayHint>>>,
     document_settings: RwLock<HashMap<Url, IdeSettings>>,
     global_settings: RwLock<IdeSettings>,
     last_validated: RwLock<Instant>,
@@ -112,6 +114,7 @@ impl Backend {
             can_publish_diagnostics: OnceLock::new(),
             client,
             documents: RwLock::new(TextDocuments::new()),
+            document_inlay_hints: RwLock::new(HashMap::new()),
             document_settings: RwLock::new(HashMap::new()),
             global_settings: RwLock::new(IdeSettings::default()),
             last_validated: RwLock::new(Instant::now()),
@@ -227,23 +230,17 @@ impl Backend {
         let text = self.for_document(uri, &|doc| String::from(doc.get_content(None)))?;
 
         let ide_settings = self.get_document_settings(uri).await?;
+        let show_inferred_types = ide_settings.hints.show_inferred_types;
         let output =
             run_compiler(&text, vec![OsStr::new("--ide-check")], ide_settings, uri).await?;
 
-        let ide_checks: Vec<IdeCheck> = output
-            .stdout
-            .lines()
-            .filter_map(|l| serde_json::from_slice(l.as_bytes()).ok())
-            .collect();
+        let ide_checks = IdeCheckResponse::from_compiler_response(&output);
 
         let (diagnostics, version) = self.for_document(uri, &|doc| {
             (
                 ide_checks
+                    .diagnostics
                     .iter()
-                    .filter_map(|c| match c {
-                        IdeCheck::Diagnostic(d) => Some(d),
-                        IdeCheck::Hint(_) => None,
-                    })
                     .map(|d| IdeCheckDiagnostic::to_diagnostic(d, doc, uri))
                     .collect::<Vec<_>>(),
                 doc.version(),
@@ -254,6 +251,21 @@ impl Backend {
             .publish_diagnostics(uri.clone(), diagnostics, Some(version))
             .await;
 
+        if show_inferred_types {
+            let inlay_hints = self.for_document(uri, &|doc| {
+                ide_checks
+                    .inlay_hints
+                    .iter()
+                    .map(|d| IdeCheckHint::to_inlay_hint(d, doc))
+                    .collect::<Vec<_>>()
+            })?;
+
+            let mut documents = self.document_inlay_hints.write().map_err(|e| {
+                map_err_to_internal_error(&e, format!("cannot write inlay hints cache: {e:?}"))
+            })?;
+            documents.insert(uri.clone(), inlay_hints);
+        }
+
         Ok(())
     }
 }

src/nu.rs

@@ -2,9 +2,10 @@ use std::{ffi::OsStr, path::PathBuf, time::Duration};
 
 use lsp_textdocument::FullTextDocument;
 use serde::Deserialize;
-use tokio::fs;
+use tokio::{fs, time::timeout};
 use tower_lsp::lsp_types::{
-    CompletionItem, CompletionItemKind, CompletionResponse, DiagnosticSeverity, Range, Url,
+    CompletionItem, CompletionItemKind, CompletionResponse, DiagnosticSeverity, InlayHint,
+    InlayHintKind, Range, Url,
 };
 use tower_lsp::{jsonrpc::Result, lsp_types::Diagnostic};
 
@@ -17,7 +18,7 @@ pub(crate) enum IdeCheck {
     Hint(IdeCheckHint),
 }
 
-#[derive(Debug, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Deserialize, PartialEq)]
 pub(crate) struct IdeCheckDiagnostic {
     pub message: String,
     pub severity: IdeDiagnosticSeverity,
@@ -38,11 +39,63 @@ impl IdeCheckDiagnostic {
     }
 }
 
-#[derive(Debug, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Deserialize, PartialEq)]
 pub(crate) struct IdeCheckHint {
     pub position: IdeSpan,
     pub typename: String,
 }
+impl IdeCheckHint {
+    pub fn to_inlay_hint(&self, doc: &FullTextDocument) -> InlayHint {
+        InlayHint {
+            position: doc.position_at(self.position.end),
+            label: tower_lsp::lsp_types::InlayHintLabel::String(format!(": {}", &self.typename)),
+            kind: Some(InlayHintKind::TYPE),
+            text_edits: None,
+            tooltip: None,
+            padding_left: None,
+            padding_right: None,
+            data: None,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq)]
+pub(crate) struct IdeCheckResponse {
+    pub diagnostics: Vec<IdeCheckDiagnostic>,
+    pub inlay_hints: Vec<IdeCheckHint>,
+}
+impl IdeCheckResponse {
+    pub fn from_compiler_response(value: &CompilerResponse) -> Self {
+        let ide_checks: Vec<IdeCheck> = value
+            .stdout
+            .lines()
+            .filter_map(|l| serde_json::from_slice(l.as_bytes()).ok())
+            .collect();
+
+        let diagnostics = ide_checks
+            .iter()
+            .filter_map(|c| match c {
+                IdeCheck::Diagnostic(d) => Some(d),
+                IdeCheck::Hint(_) => None,
+            })
+            .cloned()
+            .collect::<Vec<_>>();
+
+        let inlay_hints = ide_checks
+            .iter()
+            .filter_map(|c| match c {
+                IdeCheck::Diagnostic(_) => None,
+                IdeCheck::Hint(h) => Some(h),
+            })
+            .cloned()
+            .collect::<Vec<_>>();
+
+        Self {
+            diagnostics,
+            inlay_hints,
+        }
+    }
+}
 
 #[derive(Deserialize)]
 pub(crate) struct IdeComplete {
@@ -82,7 +135,7 @@ impl From<IdeComplete> for CompletionResponse {
     }
 }
 
-#[derive(Debug, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Deserialize, PartialEq)]
 pub(crate) enum IdeDiagnosticSeverity {
     Error,
     Warning,
@@ -113,13 +166,12 @@ pub(crate) struct IdeHover {
     pub hover: String,
     pub span: Option<IdeSpan>,
 }
-#[derive(Debug, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Deserialize, PartialEq)]
 pub(crate) struct IdeSpan {
     pub end: u32,
     pub start: u32,
 }
 
-#[allow(dead_code)]
 #[derive(Clone, Debug, Deserialize)]
 #[serde(default, rename_all = "camelCase")]
 pub(crate) struct IdeSettings {
@@ -141,7 +193,6 @@ impl Default for IdeSettings {
     }
 }
 
-#[allow(dead_code)]
 #[derive(Clone, Debug, Deserialize)]
 #[serde(default, rename_all = "camelCase")]
 pub(crate) struct IdeSettingsHints {
@@ -155,6 +206,7 @@ impl Default for IdeSettingsHints {
     }
 }
 
+#[derive(Debug)]
 pub(crate) struct CompilerResponse {
     pub cmdline: String,
     pub stdout: String,
@@ -167,8 +219,6 @@ pub(crate) async fn run_compiler(
     settings: IdeSettings,
     uri: &Url,
 ) -> Result<CompilerResponse> {
-    // TODO: support allowErrors and label options like vscode-nushell-lang?
-
     let max_number_of_problems = format!("{}", settings.max_number_of_problems);
     let max_number_of_problems_flag = OsStr::new(&max_number_of_problems);
     if flags.contains(&OsStr::new("--ide-check")) {
@@ -210,16 +260,27 @@ pub(crate) async fn run_compiler(
 
     let cmdline = format!("nu {flags:?}");
 
-    // TODO: honour max_nushell_invocation_time like vscode-nushell-lang
-    // TODO: call settings.nushell_executable_path
-
     // TODO: call nushell Rust code directly instead of via separate process,
     // https://github.com/jokeyrhyme/nuls/issues/7
-    let output = tokio::process::Command::new("nu")
-        .args(flags)
-        .output()
-        .await
-        .map_err(|e| map_err_to_internal_error(e, format!("`{cmdline}` failed")))?;
+    let output = timeout(
+        settings.max_nushell_invocation_time,
+        tokio::process::Command::new(settings.nushell_executable_path)
+            .args(flags)
+            .output(),
+    )
+    .await
+    .map_err(|e| {
+        map_err_to_internal_error(
+            e,
+            format!(
+                "`{cmdline}` timeout, {:?} elapsed",
+                &settings.max_nushell_invocation_time
+            ),
+        )
+    })?
+    .map_err(|e| map_err_to_internal_error(e, format!("`{cmdline}` failed")))?;
+    // intentionally skip checking the ExitStatus, we always want stdout regardless
+
     let stdout = String::from_utf8(output.stdout).map_err(|e| {
         map_err_to_parse_error(e, format!("`{cmdline}` did not return valid UTF-8"))
     })?;
@@ -285,7 +346,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn completion_ok() {
+    async fn run_compiler_for_completion_ok() {
         let output = run_compiler(
             "wh",
             vec![OsStr::new("--ide-complete"), OsStr::new(&format!("{}", 2))],
@@ -315,4 +376,44 @@ mod tests {
             unreachable!();
         }
     }
+
+    #[tokio::test]
+    async fn run_compiler_for_diagnostic_ok() {
+        let doc = FullTextDocument::new(
+            String::from("nushell"),
+            1,
+            String::from(
+                "
+                let foo = ['one', 'two', 'three']
+                ls ||
+                ",
+            ),
+        );
+        let uri = Url::parse("file:///foo.nu").expect("unable to parse test URL");
+        let output = run_compiler(
+            doc.get_content(None),
+            vec![OsStr::new("--ide-check")],
+            IdeSettings::default(),
+            &uri,
+        )
+        .await
+        .expect("unable to run `nu --ide-check ...`");
+
+        let got = IdeCheckResponse::from_compiler_response(&output);
+
+        assert_eq!(
+            got,
+            IdeCheckResponse {
+                diagnostics: vec![IdeCheckDiagnostic {
+                    message: String::from("The '||' operator is not supported in Nushell"),
+                    severity: IdeDiagnosticSeverity::Error,
+                    span: IdeSpan { end: 72, start: 70 }
+                }],
+                inlay_hints: vec![IdeCheckHint {
+                    position: IdeSpan { end: 24, start: 21 },
+                    typename: String::from("list<string>")
+                }],
+            }
+        );
+    }
 }