2 files changed, 272 insertions, 0 deletions
diff --git a/test_util/src/lib.rs b/test_util/src/lib.rs
index d2669e42e..4cfc5cc9c 100644
--- a/test_util/src/lib.rs
+++ b/test_util/src/lib.rs
@@ -46,6 +46,8 @@ use tokio_tungstenite::accept_async;
 #[cfg(unix)]
 pub use pty;
 
+pub mod lsp;
+
 const PORT: u16 = 4545;
 const TEST_AUTH_TOKEN: &str = "abcdef123456789";
 const REDIRECT_PORT: u16 = 4546;
diff --git a/test_util/src/lsp.rs b/test_util/src/lsp.rs
new file mode 100644
index 000000000..52099ebe3
--- /dev/null
+++ b/test_util/src/lsp.rs
@@ -0,0 +1,270 @@
+// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
+
+use super::new_deno_dir;
+
+use lazy_static::lazy_static;
+use regex::Regex;
+use serde::de;
+use serde::Deserialize;
+use serde::Serialize;
+use serde_json::json;
+use serde_json::Value;
+use std::io;
+use std::io::Write;
+use std::path::Path;
+use std::process::Child;
+use std::process::ChildStdin;
+use std::process::ChildStdout;
+use std::process::Command;
+use std::process::Stdio;
+use std::time::Duration;
+use std::time::Instant;
+
+lazy_static! {
+  static ref CONTENT_TYPE_REG: Regex =
+    Regex::new(r"(?i)^content-length:\s+(\d+)").unwrap();
+}
+
+#[derive(Debug, Deserialize, Serialize)]
+pub struct LspResponseError {
+  code: i32,
+  message: String,
+  data: Option<Value>,
+}
+
+#[derive(Debug)]
+pub enum LspMessage {
+  Notification(String, Option<Value>),
+  Request(u64, String, Option<Value>),
+  Response(u64, Option<Value>, Option<LspResponseError>),
+}
+
+impl<'a> From<&'a [u8]> for LspMessage {
+  fn from(s: &'a [u8]) -> Self {
+    let value: Value = serde_json::from_slice(s).unwrap();
+    let obj = value.as_object().unwrap();
+    if obj.contains_key("id") && obj.contains_key("method") {
+      let id = obj.get("id").unwrap().as_u64().unwrap();
+      let method = obj.get("method").unwrap().as_str().unwrap().to_string();
+      Self::Request(id, method, obj.get("params").cloned())
+    } else if obj.contains_key("id") {
+      let id = obj.get("id").unwrap().as_u64().unwrap();
+      let maybe_error: Option<LspResponseError> = obj
+        .get("error")
+        .map(|v| serde_json::from_value(v.clone()).unwrap());
+      Self::Response(id, obj.get("result").cloned(), maybe_error)
+    } else {
+      assert!(obj.contains_key("method"));
+      let method = obj.get("method").unwrap().as_str().unwrap().to_string();
+      Self::Notification(method, obj.get("params").cloned())
+    }
+  }
+}
+
+fn read_message<R>(reader: &mut R) -> Result<Vec<u8>, anyhow::Error>
+where
+  R: io::Read + io::BufRead,
+{
+  let mut content_length = 0_usize;
+  loop {
+    let mut buf = String::new();
+    reader.read_line(&mut buf)?;
+    if let Some(captures) = CONTENT_TYPE_REG.captures(&buf) {
+      let content_length_match = captures
+        .get(1)
+        .ok_or_else(|| anyhow::anyhow!("missing capture"))?;
+      content_length = content_length_match.as_str().parse::<usize>()?;
+    }
+    if &buf == "\r\n" {
+      break;
+    }
+  }
+
+  let mut msg_buf = vec![0_u8; content_length];
+  reader.read_exact(&mut msg_buf)?;
+  Ok(msg_buf)
+}
+
+pub struct LspClient {
+  reader: io::BufReader<ChildStdout>,
+  child: Child,
+  request_id: u64,
+  start: Instant,
+  writer: io::BufWriter<ChildStdin>,
+}
+
+impl Drop for LspClient {
+  fn drop(&mut self) {
+    match self.child.try_wait() {
+      Ok(None) => {
+        self.child.kill().unwrap();
+        let _ = self.child.wait();
+      }
+      Ok(Some(status)) => panic!("deno lsp exited unexpectedly {}", status),
+      Err(e) => panic!("pebble error: {}", e),
+    }
+  }
+}
+
+impl LspClient {
+  pub fn new(deno_exe: &Path) -> Result<Self, anyhow::Error> {
+    let deno_dir = new_deno_dir();
+    let mut child = Command::new(deno_exe)
+      .env("DENO_DIR", deno_dir.path())
+      .arg("lsp")
+      .stdin(Stdio::piped())
+      .stdout(Stdio::piped())
+      .stderr(Stdio::null())
+      .spawn()?;
+
+    let stdout = child.stdout.take().unwrap();
+    let reader = io::BufReader::new(stdout);
+
+    let stdin = child.stdin.take().unwrap();
+    let writer = io::BufWriter::new(stdin);
+
+    Ok(Self {
+      child,
+      reader,
+      request_id: 1,
+      start: Instant::now(),
+      writer,
+    })
+  }
+
+  pub fn duration(&self) -> Duration {
+    self.start.elapsed()
+  }
+
+  fn read(&mut self) -> Result<LspMessage, anyhow::Error> {
+    let msg_buf = read_message(&mut self.reader)?;
+    let msg = LspMessage::from(msg_buf.as_slice());
+    Ok(msg)
+  }
+
+  pub fn read_notification<R>(
+    &mut self,
+  ) -> Result<(String, Option<R>), anyhow::Error>
+  where
+    R: de::DeserializeOwned,
+  {
+    loop {
+      if let LspMessage::Notification(method, maybe_params) = self.read()? {
+        if let Some(p) = maybe_params {
+          let params = serde_json::from_value(p)?;
+          return Ok((method, Some(params)));
+        } else {
+          return Ok((method, None));
+        }
+      }
+    }
+  }
+
+  pub fn read_request<R>(
+    &mut self,
+  ) -> Result<(u64, String, Option<R>), anyhow::Error>
+  where
+    R: de::DeserializeOwned,
+  {
+    loop {
+      if let LspMessage::Request(id, method, maybe_params) = self.read()? {
+        if let Some(p) = maybe_params {
+          let params = serde_json::from_value(p)?;
+          return Ok((id, method, Some(params)));
+        } else {
+          return Ok((id, method, None));
+        }
+      }
+    }
+  }
+
+  fn write(&mut self, value: Value) -> Result<(), anyhow::Error> {
+    let value_str = value.to_string();
+    let msg = format!(
+      "Content-Length: {}\r\n\r\n{}",
+      value_str.as_bytes().len(),
+      value_str
+    );
+    self.writer.write_all(msg.as_bytes())?;
+    self.writer.flush()?;
+    Ok(())
+  }
+
+  pub fn write_request<S, V, R>(
+    &mut self,
+    method: S,
+    params: V,
+  ) -> Result<(Option<R>, Option<LspResponseError>), anyhow::Error>
+  where
+    S: AsRef<str>,
+    V: Serialize,
+    R: de::DeserializeOwned,
+  {
+    let value = json!({
+      "jsonrpc": "2.0",
+      "id": self.request_id,
+      "method": method.as_ref(),
+      "params": params,
+    });
+    self.write(value)?;
+
+    loop {
+      if let LspMessage::Response(id, result, error) = self.read()? {
+        assert_eq!(id, self.request_id);
+        self.request_id += 1;
+        if let Some(r) = result {
+          let result = serde_json::from_value(r)?;
+          return Ok((Some(result), error));
+        } else {
+          return Ok((None, error));
+        }
+      }
+    }
+  }
+
+  pub fn write_response<V>(
+    &mut self,
+    id: u64,
+    result: V,
+  ) -> Result<(), anyhow::Error>
+  where
+    V: Serialize,
+  {
+    let value = json!({
+      "jsonrpc": "2.0",
+      "id": id,
+      "result": result
+    });
+    self.write(value)
+  }
+
+  pub fn write_notification<S, V>(
+    &mut self,
+    method: S,
+    params: V,
+  ) -> Result<(), anyhow::Error>
+  where
+    S: AsRef<str>,
+    V: Serialize,
+  {
+    let value = json!({
+      "jsonrpc": "2.0",
+      "method": method.as_ref(),
+      "params": params,
+    });
+    self.write(value)?;
+    Ok(())
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn test_read_message() {
+    let msg = b"content-length: 11\r\n\r\nhello world";
+    let mut reader = std::io::Cursor::new(msg);
+    assert_eq!(read_message(&mut reader).unwrap(), b"hello world");
+  }
+}