fix(lsp): auto-discover deno.json in more cases (#19894)

We weren't auto-discovering the deno.json in two cases:

1. A project that didn't have a deno.json and just added one.
2. After a syntax error in the deno.json.

This now rediscovers it in both these cases.

Closes https://github.com/denoland/vscode_deno/issues/867

4 files changed, 202 insertions, 18 deletions

diff --git a/cli/lsp/config.rs b/cli/lsp/config.rs
index 298c86a55..03464d1f8 100644
--- a/cli/lsp/config.rs
+++ b/cli/lsp/config.rs
@@ -773,7 +773,12 @@ fn resolve_lockfile_from_path(
   lockfile_path: PathBuf,
 ) -> Option<Arc<Mutex<Lockfile>>> {
   match Lockfile::new(lockfile_path, false) {
-    Ok(value) => Some(Arc::new(Mutex::new(value))),
+    Ok(value) => {
+      if let Ok(specifier) = ModuleSpecifier::from_file_path(&value.filename) {
+        lsp_log!("  Resolved lock file: \"{}\"", specifier);
+      }
+      Some(Arc::new(Mutex::new(value)))
+    }
     Err(err) => {
       lsp_warn!("Error loading lockfile: {:#}", err);
       None
diff --git a/cli/lsp/language_server.rs b/cli/lsp/language_server.rs
index 6dead0fcf..5a4c3aeae 100644
--- a/cli/lsp/language_server.rs
+++ b/cli/lsp/language_server.rs
@@ -1493,22 +1493,30 @@ impl Inner {
       .collect();
 
     // if the current deno.json has changed, we need to reload it
-    if let Some(config_file) = self.config.maybe_config_file() {
-      if changes.contains(&config_file.specifier)
-        || self
-          .config
-          .maybe_lockfile()
-          .map(|l| has_lockfile_changed(&l.lock(), &changes))
-          .unwrap_or(false)
-      {
-        if let Err(err) = self.update_config_file().await {
-          self.client.show_message(MessageType::WARNING, err);
-        }
-        if let Err(err) = self.update_tsconfig().await {
-          self.client.show_message(MessageType::WARNING, err);
-        }
-        touched = true;
+    let has_config_changed = match self.config.maybe_config_file() {
+      Some(config_file) => changes.contains(&config_file.specifier),
+      None => {
+        // check for auto-discovery
+        changes.iter().any(|url| {
+          url.path().ends_with("/deno.json")
+            || url.path().ends_with("/deno.jsonc")
+        })
       }
+    } || match self.config.maybe_lockfile() {
+      Some(lockfile) => has_lockfile_changed(&lockfile.lock(), &changes),
+      None => {
+        // check for auto-discovery
+        changes.iter().any(|url| url.path().ends_with("/deno.lock"))
+      }
+    };
+    if has_config_changed {
+      if let Err(err) = self.update_config_file().await {
+        self.client.show_message(MessageType::WARNING, err);
+      }
+      if let Err(err) = self.update_tsconfig().await {
+        self.client.show_message(MessageType::WARNING, err);
+      }
+      touched = true;
     }
 
     if let Some(package_json) = &self.maybe_package_json {
@@ -2940,7 +2948,7 @@ impl tower_lsp::LanguageServer for LanguageServer {
         let watch_registration_options =
           DidChangeWatchedFilesRegistrationOptions {
             watchers: vec![FileSystemWatcher {
-              glob_pattern: "**/*.{json,jsonc}".to_string(),
+              glob_pattern: "**/*.{json,jsonc,lock}".to_string(),
               kind: Some(WatchKind::Change),
             }],
           };
diff --git a/cli/tests/integration/lsp_tests.rs b/cli/tests/integration/lsp_tests.rs
index 22463b58a..261c98b52 100644
--- a/cli/tests/integration/lsp_tests.rs
+++ b/cli/tests/integration/lsp_tests.rs
@@ -433,6 +433,118 @@ fn lsp_import_map_embedded_in_config_file_after_initialize() {
 }
 
 #[test]
+fn lsp_import_map_config_file_auto_discovered() {
+  let context = TestContextBuilder::new().use_temp_cwd().build();
+  let temp_dir = context.temp_dir();
+  temp_dir.create_dir_all("lib");
+  temp_dir.write("lib/b.ts", r#"export const b = "b";"#);
+
+  let mut client = context.new_lsp_command().capture_stderr().build();
+  client.initialize_default();
+
+  // add the deno.json
+  temp_dir.write("deno.jsonc", r#"{ "imports": { "/~/": "./lib/" } }"#);
+  client.did_change_watched_files(json!({
+    "changes": [{
+      "uri": temp_dir.uri().join("deno.jsonc").unwrap(),
+      "type": 2
+    }]
+  }));
+  client.wait_until_stderr_line(|line| {
+    line.contains("Auto-resolved configuration file:")
+  });
+
+  let uri = temp_dir.uri().join("a.ts").unwrap();
+
+  let diagnostics = client.did_open(json!({
+    "textDocument": {
+      "uri": uri,
+      "languageId": "typescript",
+      "version": 1,
+      "text": "import { b } from \"/~/b.ts\";\n\nconsole.log(b);\n"
+    }
+  }));
+
+  assert_eq!(diagnostics.all().len(), 0);
+
+  let res = client.write_request(
+    "textDocument/hover",
+    json!({
+      "textDocument": {
+        "uri": uri
+      },
+      "position": { "line": 2, "character": 12 }
+    }),
+  );
+  assert_eq!(
+    res,
+    json!({
+      "contents": [
+        {
+          "language": "typescript",
+          "value":"(alias) const b: \"b\"\nimport b"
+        },
+        ""
+      ],
+      "range": {
+        "start": { "line": 2, "character": 12 },
+        "end": { "line": 2, "character": 13 }
+      }
+    })
+  );
+
+  // now cause a syntax error
+  temp_dir.write("deno.jsonc", r#",,#,#,,"#);
+  client.did_change_watched_files(json!({
+    "changes": [{
+      "uri": temp_dir.uri().join("deno.jsonc").unwrap(),
+      "type": 2
+    }]
+  }));
+  assert_eq!(client.read_diagnostics().all().len(), 1);
+
+  // now fix it, and things should work again
+  temp_dir.write("deno.jsonc", r#"{ "imports": { "/~/": "./lib/" } }"#);
+  client.did_change_watched_files(json!({
+    "changes": [{
+      "uri": temp_dir.uri().join("deno.jsonc").unwrap(),
+      "type": 2
+    }]
+  }));
+  client.wait_until_stderr_line(|line| {
+    line.contains("Auto-resolved configuration file:")
+  });
+  let res = client.write_request(
+    "textDocument/hover",
+    json!({
+      "textDocument": {
+        "uri": uri
+      },
+      "position": { "line": 2, "character": 12 }
+    }),
+  );
+  assert_eq!(
+    res,
+    json!({
+      "contents": [
+        {
+          "language": "typescript",
+          "value":"(alias) const b: \"b\"\nimport b"
+        },
+        ""
+      ],
+      "range": {
+        "start": { "line": 2, "character": 12 },
+        "end": { "line": 2, "character": 13 }
+      }
+    })
+  );
+  assert_eq!(client.read_diagnostics().all().len(), 0);
+
+  client.shutdown();
+}
+
+#[test]
 fn lsp_deno_task() {
   let context = TestContextBuilder::new().use_temp_cwd().build();
   let temp_dir = context.temp_dir();
diff --git a/test_util/src/lsp.rs b/test_util/src/lsp.rs
index cd546bd6c..6fafc234c 100644
--- a/test_util/src/lsp.rs
+++ b/test_util/src/lsp.rs
@@ -37,6 +37,8 @@ use serde_json::to_value;
 use serde_json::Value;
 use std::collections::HashSet;
 use std::io;
+use std::io::BufRead;
+use std::io::BufReader;
 use std::io::Write;
 use std::path::Path;
 use std::process::Child;
@@ -44,6 +46,7 @@ use std::process::ChildStdin;
 use std::process::ChildStdout;
 use std::process::Command;
 use std::process::Stdio;
+use std::sync::mpsc;
 use std::sync::Arc;
 use std::time::Duration;
 use std::time::Instant;
@@ -468,6 +471,7 @@ impl InitializeParamsBuilder {
 
 pub struct LspClientBuilder {
   print_stderr: bool,
+  capture_stderr: bool,
   deno_exe: PathRef,
   context: Option<TestContext>,
   use_diagnostic_sync: bool,
@@ -478,6 +482,7 @@ impl LspClientBuilder {
   pub fn new() -> Self {
     Self {
       print_stderr: false,
+      capture_stderr: false,
       deno_exe: deno_exe_path(),
       context: None,
       use_diagnostic_sync: true,
@@ -497,6 +502,11 @@ impl LspClientBuilder {
     self
   }
 
+  pub fn capture_stderr(&mut self) -> &mut Self {
+    self.capture_stderr = true;
+    self
+  }
+
   /// Whether to use the synchronization messages to better sync diagnostics
   /// between the test client and server.
   pub fn use_diagnostic_sync(&mut self, value: bool) -> &mut Self {
@@ -527,7 +537,9 @@ impl LspClientBuilder {
       .arg("lsp")
       .stdin(Stdio::piped())
       .stdout(Stdio::piped());
-    if !self.print_stderr {
+    if self.capture_stderr {
+      command.stderr(Stdio::piped());
+    } else if !self.print_stderr {
       command.stderr(Stdio::null());
     }
     let mut child = command.spawn()?;
@@ -538,6 +550,31 @@ impl LspClientBuilder {
     let stdin = child.stdin.take().unwrap();
     let writer = io::BufWriter::new(stdin);
 
+    let stderr_lines_rx = if self.capture_stderr {
+      let stderr = child.stderr.take().unwrap();
+      let print_stderr = self.print_stderr;
+      let (tx, rx) = mpsc::channel::<String>();
+      std::thread::spawn(move || {
+        let stderr = BufReader::new(stderr);
+        for line in stderr.lines() {
+          match line {
+            Ok(line) => {
+              if print_stderr {
+                eprintln!("{}", line);
+              }
+              tx.send(line).unwrap();
+            }
+            Err(err) => {
+              panic!("failed to read line from stderr: {:#}", err);
+            }
+          }
+        }
+      });
+      Some(rx)
+    } else {
+      None
+    };
+
     Ok(LspClient {
       child,
       reader,
@@ -549,6 +586,7 @@ impl LspClientBuilder {
         .unwrap_or_else(|| TestContextBuilder::new().build()),
       writer,
       deno_dir,
+      stderr_lines_rx,
     })
   }
 }
@@ -561,6 +599,7 @@ pub struct LspClient {
   writer: io::BufWriter<ChildStdin>,
   deno_dir: TempDir,
   context: TestContext,
+  stderr_lines_rx: Option<mpsc::Receiver<String>>,
 }
 
 impl Drop for LspClient {
@@ -594,6 +633,26 @@ impl LspClient {
     self.reader.pending_len()
   }
 
+  #[track_caller]
+  pub fn wait_until_stderr_line(&self, condition: impl Fn(&str) -> bool) {
+    let timeout_time =
+      Instant::now().checked_add(Duration::from_secs(5)).unwrap();
+    let lines_rx = self
+      .stderr_lines_rx
+      .as_ref()
+      .expect("must setup with client_builder.capture_stderr()");
+    while Instant::now() < timeout_time {
+      if let Ok(line) = lines_rx.try_recv() {
+        if condition(&line) {
+          return;
+        }
+      }
+      std::thread::sleep(Duration::from_millis(20));
+    }
+
+    panic!("Timed out.")
+  }
+
   pub fn initialize_default(&mut self) {
     self.initialize(|_| {})
   }