7 files changed, 1687 insertions, 0 deletions
diff --git a/helix-dap/Cargo.toml b/helix-dap/Cargo.toml
new file mode 100644
index 00000000..6870adb6
--- /dev/null
+++ b/helix-dap/Cargo.toml
@@ -0,0 +1,24 @@
+[package]
+name = "helix-dap"
+version = "0.5.0"
+authors = ["Blaž Hrastnik <blaz@mxxn.io>"]
+edition = "2018"
+license = "MPL-2.0"
+description = "DAP client implementation for Helix project"
+categories = ["editor"]
+repository = "https://github.com/helix-editor/helix"
+homepage = "https://helix-editor.com"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+helix-core = { version = "0.4", path = "../helix-core" }
+anyhow = "1.0"
+log = "0.4"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+thiserror = "1.0"
+tokio = { version = "1", features = ["rt", "rt-multi-thread", "io-util", "io-std", "time", "process", "macros", "fs", "parking_lot", "net", "sync"] }
+
+[dev-dependencies]
+fern = "0.6"
diff --git a/helix-dap/examples/dap-dlv.rs b/helix-dap/examples/dap-dlv.rs
new file mode 100644
index 00000000..24b26a74
--- /dev/null
+++ b/helix-dap/examples/dap-dlv.rs
@@ -0,0 +1,125 @@
+use helix_dap::{events, Client, Event, Payload, Result, SourceBreakpoint, ThreadId};
+use serde::{Deserialize, Serialize};
+use serde_json::to_value;
+use tokio::sync::mpsc::UnboundedReceiver;
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct LaunchArguments {
+    mode: String,
+    program: String,
+}
+
+async fn dispatch(mut rx: UnboundedReceiver<Payload>) {
+    loop {
+        match rx.recv().await.unwrap() {
+            Payload::Event(Event::Output(events::Output {
+                category, output, ..
+            })) => {
+                println!(
+                    "> [{}] {}",
+                    category.unwrap_or("unknown".to_owned()),
+                    output
+                );
+            }
+            Payload::Event(Event::Stopped(_)) => {
+                println!("stopped");
+            }
+            _ => {}
+        };
+    }
+}
+
+#[tokio::main]
+pub async fn main() -> Result<()> {
+    let base_config = fern::Dispatch::new().level(log::LevelFilter::Info);
+
+    let stderr_config = fern::Dispatch::new()
+        .format(|out, message, record| out.finish(format_args!("[{}] {}", record.level(), message)))
+        .chain(std::io::stderr());
+
+    base_config
+        .chain(stderr_config)
+        .apply()
+        .expect("Failed to set up logging");
+
+    let (mut client, events) =
+        Client::tcp_process("dlv", vec!["dap"], "-l 127.0.0.1:{}", 0).await?;
+    println!("create: {:?}", client);
+
+    tokio::spawn(dispatch(events));
+
+    println!("init: {:?}", client.initialize("go".to_owned()).await);
+    println!("caps: {:?}", client.capabilities());
+
+    let args = LaunchArguments {
+        mode: "exec".to_owned(),
+        program: "/tmp/godebug/main".to_owned(),
+    };
+
+    println!("launch: {:?}", client.launch(to_value(args)?).await);
+
+    println!(
+        "breakpoints: {:#?}",
+        client
+            .set_breakpoints(
+                "/tmp/godebug/main.go".into(),
+                vec![SourceBreakpoint {
+                    line: 8,
+                    column: Some(2),
+                    condition: None,
+                    hit_condition: None,
+                    log_message: None,
+                }]
+            )
+            .await
+    );
+
+    let mut _in = String::new();
+    std::io::stdin()
+        .read_line(&mut _in)
+        .expect("Failed to read line");
+
+    println!("configurationDone: {:?}", client.configuration_done().await);
+
+    let mut _in = String::new();
+    std::io::stdin()
+        .read_line(&mut _in)
+        .expect("Failed to read line");
+
+    let threads = client.threads().await?;
+    println!("threads: {:#?}", threads);
+    let bt = client
+        .stack_trace(threads[0].id)
+        .await
+        .expect("expected stack trace");
+    println!("stack trace: {:#?}", bt);
+    let scopes = client
+        .scopes(bt.0[0].id)
+        .await
+        .expect("expected scopes for thread");
+    println!("scopes: {:#?}", scopes);
+    println!(
+        "vars: {:#?}",
+        client.variables(scopes[1].variables_reference).await
+    );
+
+    let mut _in = String::new();
+    std::io::stdin()
+        .read_line(&mut _in)
+        .expect("Failed to read line");
+
+    println!(
+        "continued: {:?}",
+        client.continue_thread(ThreadId::default()).await
+    );
+
+    let mut _in = String::new();
+    std::io::stdin()
+        .read_line(&mut _in)
+        .expect("Failed to read line");
+
+    println!("disconnect: {:?}", client.disconnect().await);
+
+    Ok(())
+}
diff --git a/helix-dap/examples/dap-lldb.rs b/helix-dap/examples/dap-lldb.rs
new file mode 100644
index 00000000..935de5fe
--- /dev/null
+++ b/helix-dap/examples/dap-lldb.rs
@@ -0,0 +1,127 @@
+use helix_dap::{events, Client, Event, Payload, Result, SourceBreakpoint, ThreadId};
+use serde::{Deserialize, Serialize};
+use serde_json::to_value;
+use tokio::sync::mpsc::UnboundedReceiver;
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct LaunchArguments {
+    program: String,
+    console: String,
+}
+
+async fn dispatch(mut rx: UnboundedReceiver<Payload>) {
+    loop {
+        match rx.recv().await.unwrap() {
+            Payload::Event(Event::Output(events::Output {
+                category, output, ..
+            })) => {
+                println!(
+                    "> [{}] {}",
+                    category.unwrap_or("unknown".to_owned()),
+                    output
+                );
+            }
+            Payload::Event(Event::Stopped(_)) => {
+                println!("stopped");
+            }
+            _ => {}
+        };
+    }
+}
+
+#[tokio::main]
+pub async fn main() -> Result<()> {
+    let base_config = fern::Dispatch::new().level(log::LevelFilter::Info);
+
+    let stderr_config = fern::Dispatch::new()
+        .format(|out, message, record| out.finish(format_args!("[{}] {}", record.level(), message)))
+        .chain(std::io::stderr());
+
+    base_config
+        .chain(stderr_config)
+        .apply()
+        .expect("Failed to set up logging");
+
+    let (mut client, events) = Client::tcp_process("lldb-vscode", vec![], "-p {}", 0).await?;
+    println!("create: {:?}", client);
+
+    tokio::spawn(dispatch(events));
+
+    println!(
+        "init: {:?}",
+        client.initialize("lldb-vscode".to_owned()).await
+    );
+    println!("caps: {:?}", client.capabilities());
+
+    let args = LaunchArguments {
+        program: "/tmp/cdebug/main".to_owned(),
+        console: "internalConsole".to_owned(),
+    };
+
+    println!("launch: {:?}", client.launch(to_value(args)?).await);
+
+    println!(
+        "breakpoints: {:#?}",
+        client
+            .set_breakpoints(
+                "/tmp/cdebug/main.c".into(),
+                vec![SourceBreakpoint {
+                    line: 6,
+                    column: Some(2),
+                    condition: None,
+                    hit_condition: None,
+                    log_message: None,
+                }]
+            )
+            .await
+    );
+
+    let mut _in = String::new();
+    std::io::stdin()
+        .read_line(&mut _in)
+        .expect("Failed to read line");
+
+    println!("configurationDone: {:?}", client.configuration_done().await);
+
+    let mut _in = String::new();
+    std::io::stdin()
+        .read_line(&mut _in)
+        .expect("Failed to read line");
+
+    let threads = client.threads().await?;
+    println!("threads: {:#?}", threads);
+    let bt = client
+        .stack_trace(threads[0].id)
+        .await
+        .expect("expected stack trace");
+    println!("stack trace: {:#?}", bt);
+    let scopes = client
+        .scopes(bt.0[0].id)
+        .await
+        .expect("expected scopes for thread");
+    println!("scopes: {:#?}", scopes);
+    println!(
+        "vars: {:#?}",
+        client.variables(scopes[0].variables_reference).await
+    );
+
+    let mut _in = String::new();
+    std::io::stdin()
+        .read_line(&mut _in)
+        .expect("Failed to read line");
+
+    println!(
+        "continued: {:?}",
+        client.continue_thread(ThreadId::default()).await
+    );
+
+    let mut _in = String::new();
+    std::io::stdin()
+        .read_line(&mut _in)
+        .expect("Failed to read line");
+
+    println!("disconnect: {:?}", client.disconnect().await);
+
+    Ok(())
+}
diff --git a/helix-dap/src/client.rs b/helix-dap/src/client.rs
new file mode 100644
index 00000000..28cc7c90
--- /dev/null
+++ b/helix-dap/src/client.rs
@@ -0,0 +1,422 @@
+use crate::{
+    transport::{Payload, Request, Transport},
+    types::*,
+    Error, Result, ThreadId,
+};
+use helix_core::syntax::DebuggerQuirks;
+
+use anyhow::anyhow;
+pub use log::{error, info};
+use std::{
+    collections::HashMap,
+    net::{IpAddr, Ipv4Addr, SocketAddr},
+    path::PathBuf,
+    process::Stdio,
+    sync::atomic::{AtomicU64, Ordering},
+};
+use tokio::{
+    io::{AsyncBufRead, AsyncWrite, BufReader, BufWriter},
+    net::TcpStream,
+    process::{Child, Command},
+    sync::mpsc::{channel, unbounded_channel, UnboundedReceiver, UnboundedSender},
+    time,
+};
+
+#[derive(Debug)]
+pub struct Client {
+    id: usize,
+    _process: Option<Child>,
+    server_tx: UnboundedSender<Request>,
+    request_counter: AtomicU64,
+    pub caps: Option<DebuggerCapabilities>,
+    // thread_id -> frames
+    pub stack_frames: HashMap<ThreadId, Vec<StackFrame>>,
+    pub thread_states: HashMap<ThreadId, String>,
+    pub thread_id: Option<ThreadId>,
+    /// Currently active frame for the current thread.
+    pub active_frame: Option<usize>,
+    pub breakpoints: Vec<Breakpoint>,
+    pub quirks: DebuggerQuirks,
+}
+
+impl Client {
+    // Spawn a process and communicate with it by either TCP or stdio
+    pub async fn process(
+        transport: String,
+        command: String,
+        args: Vec<String>,
+        port_arg: Option<String>,
+        id: usize,
+    ) -> Result<(Self, UnboundedReceiver<Payload>)> {
+        if command.is_empty() {
+            return Result::Err(Error::Other(anyhow!("Command not provided")));
+        }
+        if transport == "tcp" && port_arg.is_some() {
+            Self::tcp_process(
+                &command,
+                args.iter().map(|s| s.as_str()).collect(),
+                &port_arg.unwrap(),
+                id,
+            )
+            .await
+        } else if transport == "stdio" {
+            Self::stdio(&command, args.iter().map(|s| s.as_str()).collect(), id)
+        } else {
+            Result::Err(Error::Other(anyhow!("Incorrect transport {}", transport)))
+        }
+    }
+
+    pub fn streams(
+        rx: Box<dyn AsyncBufRead + Unpin + Send>,
+        tx: Box<dyn AsyncWrite + Unpin + Send>,
+        err: Option<Box<dyn AsyncBufRead + Unpin + Send>>,
+        id: usize,
+        process: Option<Child>,
+    ) -> Result<(Self, UnboundedReceiver<Payload>)> {
+        let (server_rx, server_tx) = Transport::start(rx, tx, err, id);
+        let (client_rx, client_tx) = unbounded_channel();
+
+        let client = Self {
+            id,
+            _process: process,
+            server_tx,
+            request_counter: AtomicU64::new(0),
+            caps: None,
+            //
+            stack_frames: HashMap::new(),
+            thread_states: HashMap::new(),
+            thread_id: None,
+            active_frame: None,
+            breakpoints: vec![],
+            quirks: DebuggerQuirks::default(),
+        };
+
+        tokio::spawn(Self::recv(server_rx, client_rx));
+
+        Ok((client, client_tx))
+    }
+
+    pub async fn tcp(
+        addr: std::net::SocketAddr,
+        id: usize,
+    ) -> Result<(Self, UnboundedReceiver<Payload>)> {
+        let stream = TcpStream::connect(addr).await?;
+        let (rx, tx) = stream.into_split();
+        Self::streams(Box::new(BufReader::new(rx)), Box::new(tx), None, id, None)
+    }
+
+    pub fn stdio(
+        cmd: &str,
+        args: Vec<&str>,
+        id: usize,
+    ) -> Result<(Self, UnboundedReceiver<Payload>)> {
+        let process = Command::new(cmd)
+            .args(args)
+            .stdin(Stdio::piped())
+            .stdout(Stdio::piped())
+            // make sure the process is reaped on drop
+            .kill_on_drop(true)
+            .spawn();
+
+        let mut process = process?;
+
+        // TODO: do we need bufreader/writer here? or do we use async wrappers on unblock?
+        let writer = BufWriter::new(process.stdin.take().expect("Failed to open stdin"));
+        let reader = BufReader::new(process.stdout.take().expect("Failed to open stdout"));
+        let errors = process.stderr.take().map(BufReader::new);
+
+        Self::streams(
+            Box::new(BufReader::new(reader)),
+            Box::new(writer),
+            // errors.map(|errors| Box::new(BufReader::new(errors))),
+            match errors {
+                Some(errors) => Some(Box::new(BufReader::new(errors))),
+                None => None,
+            },
+            id,
+            Some(process),
+        )
+    }
+
+    async fn get_port() -> Option<u16> {
+        Some(
+            tokio::net::TcpListener::bind(SocketAddr::new(
+                IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
+                0,
+            ))
+            .await
+            .ok()?
+            .local_addr()
+            .ok()?
+            .port(),
+        )
+    }
+
+    pub async fn tcp_process(
+        cmd: &str,
+        args: Vec<&str>,
+        port_format: &str,
+        id: usize,
+    ) -> Result<(Self, UnboundedReceiver<Payload>)> {
+        let port = Self::get_port().await.unwrap();
+
+        let process = Command::new(cmd)
+            .args(args)
+            .args(port_format.replace("{}", &port.to_string()).split(' '))
+            // silence messages
+            .stdin(Stdio::null())
+            .stdout(Stdio::null())
+            .stderr(Stdio::null())
+            // Do not kill debug adapter when leaving, it should exit automatically
+            .spawn()?;
+
+        // Wait for adapter to become ready for connection
+        time::sleep(time::Duration::from_millis(500)).await;
+
+        let stream = TcpStream::connect(SocketAddr::new(
+            IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
+            port,
+        ))
+        .await?;
+
+        let (rx, tx) = stream.into_split();
+        Self::streams(
+            Box::new(BufReader::new(rx)),
+            Box::new(tx),
+            None,
+            id,
+            Some(process),
+        )
+    }
+
+    async fn recv(mut server_rx: UnboundedReceiver<Payload>, client_tx: UnboundedSender<Payload>) {
+        while let Some(msg) = server_rx.recv().await {
+            match msg {
+                Payload::Event(ev) => {
+                    client_tx.send(Payload::Event(ev)).expect("Failed to send");
+                }
+                Payload::Response(_) => unreachable!(),
+                Payload::Request(req) => {
+                    client_tx
+                        .send(Payload::Request(req))
+                        .expect("Failed to send");
+                }
+            }
+        }
+    }
+
+    pub fn id(&self) -> usize {
+        self.id
+    }
+
+    fn next_request_id(&self) -> u64 {
+        self.request_counter.fetch_add(1, Ordering::Relaxed)
+    }
+
+    async fn request<R: crate::types::Request>(
+        &self,
+        arguments: R::Arguments,
+    ) -> Result<R::Result> {
+        let (callback_tx, mut callback_rx) = channel(1);
+
+        let arguments = Some(serde_json::to_value(arguments)?);
+
+        let req = Request {
+            back_ch: Some(callback_tx),
+            seq: self.next_request_id(),
+            command: R::COMMAND.to_string(),
+            arguments,
+        };
+
+        self.server_tx
+            .send(req)
+            .expect("Failed to send request to debugger");
+
+        let response = callback_rx.recv().await.unwrap()?;
+        let response = serde_json::from_value(response.body.unwrap_or_default())?;
+        Ok(response)
+    }
+
+    pub fn capabilities(&self) -> &DebuggerCapabilities {
+        self.caps.as_ref().expect("debugger not yet initialized!")
+    }
+
+    pub async fn initialize(&mut self, adapter_id: String) -> Result<()> {
+        let args = requests::InitializeArguments {
+            client_id: Some("hx".to_owned()),
+            client_name: Some("helix".to_owned()),
+            adapter_id,
+            locale: Some("en-us".to_owned()),
+            lines_start_at_one: Some(true),
+            columns_start_at_one: Some(true),
+            path_format: Some("path".to_owned()),
+            supports_variable_type: Some(true),
+            supports_variable_paging: Some(false),
+            supports_run_in_terminal_request: Some(false),
+            supports_memory_references: Some(false),
+            supports_progress_reporting: Some(false),
+            supports_invalidated_event: Some(false),
+        };
+
+        let response = self.request::<requests::Initialize>(args).await?;
+        self.caps = Some(response);
+
+        Ok(())
+    }
+
+    pub async fn disconnect(&mut self) -> Result<()> {
+        self.request::<requests::Disconnect>(()).await
+    }
+
+    pub async fn launch(&mut self, args: serde_json::Value) -> Result<()> {
+        let response = self.request::<requests::Launch>(args).await?;
+        log::error!("launch response {}", response);
+
+        Ok(())
+    }
+
+    pub async fn attach(&mut self, args: serde_json::Value) -> Result<()> {
+        let response = self.request::<requests::Attach>(args).await?;
+        log::error!("attach response {}", response);
+
+        Ok(())
+    }
+
+    pub async fn set_breakpoints(
+        &mut self,
+        file: PathBuf,
+        breakpoints: Vec<SourceBreakpoint>,
+    ) -> Result<Option<Vec<Breakpoint>>> {
+        let args = requests::SetBreakpointsArguments {
+            source: Source {
+                path: Some(file),
+                name: None,
+                source_reference: None,
+                presentation_hint: None,
+                origin: None,
+                sources: None,
+                adapter_data: None,
+                checksums: None,
+            },
+            breakpoints: Some(breakpoints),
+            source_modified: Some(false),
+        };
+
+        let response = self.request::<requests::SetBreakpoints>(args).await?;
+
+        Ok(response.breakpoints)
+    }
+
+    pub async fn configuration_done(&mut self) -> Result<()> {
+        self.request::<requests::ConfigurationDone>(()).await
+    }
+
+    pub async fn continue_thread(&mut self, thread_id: ThreadId) -> Result<Option<bool>> {
+        let args = requests::ContinueArguments { thread_id };
+
+        let response = self.request::<requests::Continue>(args).await?;
+        Ok(response.all_threads_continued)
+    }
+
+    pub async fn stack_trace(
+        &mut self,
+        thread_id: ThreadId,
+    ) -> Result<(Vec<StackFrame>, Option<usize>)> {
+        let args = requests::StackTraceArguments {
+            thread_id,
+            start_frame: None,
+            levels: None,
+            format: None,
+        };
+
+        let response = self.request::<requests::StackTrace>(args).await?;
+        Ok((response.stack_frames, response.total_frames))
+    }
+
+    pub async fn threads(&mut self) -> Result<Vec<Thread>> {
+        let response = self.request::<requests::Threads>(()).await?;
+        Ok(response.threads)
+    }
+
+    pub async fn scopes(&mut self, frame_id: usize) -> Result<Vec<Scope>> {
+        let args = requests::ScopesArguments { frame_id };
+
+        let response = self.request::<requests::Scopes>(args).await?;
+        Ok(response.scopes)
+    }
+
+    pub async fn variables(&mut self, variables_reference: usize) -> Result<Vec<Variable>> {
+        let args = requests::VariablesArguments {
+            variables_reference,
+            filter: None,
+            start: None,
+            count: None,
+            format: None,
+        };
+
+        let response = self.request::<requests::Variables>(args).await?;
+        Ok(response.variables)
+    }
+
+    pub async fn step_in(&mut self, thread_id: ThreadId) -> Result<()> {
+        let args = requests::StepInArguments {
+            thread_id,
+            target_id: None,
+            granularity: None,
+        };
+
+        self.request::<requests::StepIn>(args).await
+    }
+
+    pub async fn step_out(&mut self, thread_id: ThreadId) -> Result<()> {
+        let args = requests::StepOutArguments {
+            thread_id,
+            granularity: None,
+        };
+
+        self.request::<requests::StepOut>(args).await
+    }
+
+    pub async fn next(&mut self, thread_id: ThreadId) -> Result<()> {
+        let args = requests::NextArguments {
+            thread_id,
+            granularity: None,
+        };
+
+        self.request::<requests::Next>(args).await
+    }
+
+    pub async fn pause(&mut self, thread_id: ThreadId) -> Result<()> {
+        let args = requests::PauseArguments { thread_id };
+
+        self.request::<requests::Pause>(args).await
+    }
+
+    pub async fn eval(
+        &mut self,
+        expression: String,
+        frame_id: Option<usize>,
+    ) -> Result<requests::EvaluateResponse> {
+        let args = requests::EvaluateArguments {
+            expression,
+            frame_id,
+            context: None,
+            format: None,
+        };
+
+        self.request::<requests::Evaluate>(args).await
+    }
+
+    pub async fn set_exception_breakpoints(
+        &mut self,
+        filters: Vec<String>,
+    ) -> Result<Option<Vec<Breakpoint>>> {
+        let args = requests::SetExceptionBreakpointsArguments { filters };
+
+        let response = self
+            .request::<requests::SetExceptionBreakpoints>(args)
+            .await;
+
+        Ok(response.ok().map(|r| r.breakpoints).unwrap_or_default())
+    }
+}
diff --git a/helix-dap/src/lib.rs b/helix-dap/src/lib.rs
new file mode 100644
index 00000000..f60b102c
--- /dev/null
+++ b/helix-dap/src/lib.rs
@@ -0,0 +1,24 @@
+mod client;
+mod transport;
+mod types;
+
+pub use client::Client;
+pub use events::Event;
+pub use transport::{Payload, Response, Transport};
+pub use types::*;
+
+use thiserror::Error;
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error("failed to parse: {0}")]
+    Parse(#[from] serde_json::Error),
+    #[error("IO Error: {0}")]
+    IO(#[from] std::io::Error),
+    #[error("request timed out")]
+    Timeout,
+    #[error("server closed the stream")]
+    StreamClosed,
+    #[error(transparent)]
+    Other(#[from] anyhow::Error),
+}
+pub type Result<T> = core::result::Result<T, Error>;
diff --git a/helix-dap/src/transport.rs b/helix-dap/src/transport.rs
new file mode 100644
index 00000000..3f4eec43
--- /dev/null
+++ b/helix-dap/src/transport.rs
@@ -0,0 +1,279 @@
+use crate::{Error, Event, Result};
+use anyhow::Context;
+use log::{error, info, warn};
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+use std::collections::HashMap;
+use std::sync::Arc;
+use tokio::{
+    io::{AsyncBufRead, AsyncBufReadExt, AsyncReadExt, AsyncWrite, AsyncWriteExt},
+    sync::{
+        mpsc::{unbounded_channel, Sender, UnboundedReceiver, UnboundedSender},
+        Mutex,
+    },
+};
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct Request {
+    #[serde(skip)]
+    pub back_ch: Option<Sender<Result<Response>>>,
+    pub seq: u64,
+    pub command: String,
+    pub arguments: Option<Value>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+pub struct Response {
+    // seq is omitted as unused and is not sent by some implementations
+    pub request_seq: u64,
+    pub success: bool,
+    pub command: String,
+    pub message: Option<String>,
+    pub body: Option<Value>,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+#[serde(tag = "type", rename_all = "camelCase")]
+pub enum Payload {
+    // type = "event"
+    Event(Event),
+    // type = "response"
+    Response(Response),
+    // type = "request"
+    Request(Request),
+}
+
+#[derive(Debug)]
+pub struct Transport {
+    id: usize,
+    pending_requests: Mutex<HashMap<u64, Sender<Result<Response>>>>,
+}
+
+impl Transport {
+    pub fn start(
+        server_stdout: Box<dyn AsyncBufRead + Unpin + Send>,
+        server_stdin: Box<dyn AsyncWrite + Unpin + Send>,
+        server_stderr: Option<Box<dyn AsyncBufRead + Unpin + Send>>,
+        id: usize,
+    ) -> (UnboundedReceiver<Payload>, UnboundedSender<Request>) {
+        let (client_tx, rx) = unbounded_channel();
+        let (tx, client_rx) = unbounded_channel();
+
+        let transport = Self {
+            id,
+            pending_requests: Mutex::new(HashMap::default()),
+        };
+
+        let transport = Arc::new(transport);
+
+        tokio::spawn(Self::recv(transport.clone(), server_stdout, client_tx));
+        tokio::spawn(Self::send(transport, server_stdin, client_rx));
+        if let Some(stderr) = server_stderr {
+            tokio::spawn(Self::err(stderr));
+        }
+
+        (rx, tx)
+    }
+
+    async fn recv_server_message(
+        reader: &mut Box<dyn AsyncBufRead + Unpin + Send>,
+        buffer: &mut String,
+    ) -> Result<Payload> {
+        let mut content_length = None;
+        loop {
+            buffer.truncate(0);
+            if reader.read_line(buffer).await? == 0 {
+                return Err(Error::StreamClosed);
+            };
+
+            if buffer == "\r\n" {
+                // look for an empty CRLF line
+                break;
+            }
+
+            let header = buffer.trim();
+            let parts = header.split_once(": ");
+
+            match parts {
+                Some(("Content-Length", value)) => {
+                    content_length = Some(value.parse().context("invalid content length")?);
+                }
+                Some((_, _)) => {}
+                None => {
+                    // Workaround: Some non-conformant language servers will output logging and other garbage
+                    // into the same stream as JSON-RPC messages. This can also happen from shell scripts that spawn
+                    // the server. Skip such lines and log a warning.
+
+                    // warn!("Failed to parse header: {:?}", header);
+                }
+            }
+        }
+
+        let content_length = content_length.context("missing content length")?;
+
+        //TODO: reuse vector
+        let mut content = vec![0; content_length];
+        reader.read_exact(&mut content).await?;
+        let msg = std::str::from_utf8(&content).context("invalid utf8 from server")?;
+
+        info!("<- DAP {}", msg);
+
+        // try parsing as output (server response) or call (server request)
+        let output: serde_json::Result<Payload> = serde_json::from_str(msg);
+
+        Ok(output?)
+    }
+
+    async fn recv_server_error(
+        err: &mut (impl AsyncBufRead + Unpin + Send),
+        buffer: &mut String,
+    ) -> Result<()> {
+        buffer.truncate(0);
+        if err.read_line(buffer).await? == 0 {
+            return Err(Error::StreamClosed);
+        };
+        error!("err <- {}", buffer);
+
+        Ok(())
+    }
+
+    async fn send_payload_to_server(
+        &self,
+        server_stdin: &mut Box<dyn AsyncWrite + Unpin + Send>,
+        mut req: Request,
+    ) -> Result<()> {
+        let back_ch = req.back_ch.take();
+        let seq = req.seq;
+        let json = serde_json::to_string(&Payload::Request(req))?;
+        if let Some(back) = back_ch {
+            self.pending_requests.lock().await.insert(seq, back);
+        }
+        self.send_string_to_server(server_stdin, json).await
+    }
+
+    async fn send_string_to_server(
+        &self,
+        server_stdin: &mut Box<dyn AsyncWrite + Unpin + Send>,
+        request: String,
+    ) -> Result<()> {
+        info!("-> DAP {}", request);
+
+        // send the headers
+        server_stdin
+            .write_all(format!("Content-Length: {}\r\n\r\n", request.len()).as_bytes())
+            .await?;
+
+        // send the body
+        server_stdin.write_all(request.as_bytes()).await?;
+
+        server_stdin.flush().await?;
+
+        Ok(())
+    }
+
+    fn process_response(res: Response) -> Result<Response> {
+        if res.success {
+            info!("<- DAP success in response to {}", res.request_seq);
+
+            Ok(res)
+        } else {
+            error!(
+                "<- DAP error {:?} ({:?}) for command #{} {}",
+                res.message, res.body, res.request_seq, res.command
+            );
+
+            Err(Error::Other(anyhow::format_err!("{:?}", res.body)))
+        }
+    }
+
+    async fn process_server_message(
+        &self,
+        client_tx: &UnboundedSender<Payload>,
+        msg: Payload,
+    ) -> Result<()> {
+        match msg {
+            Payload::Response(res) => {
+                let request_seq = res.request_seq;
+                let tx = self.pending_requests.lock().await.remove(&request_seq);
+
+                match tx {
+                    Some(tx) => match tx.send(Self::process_response(res)).await {
+                        Ok(_) => (),
+                        Err(_) => error!(
+                            "Tried sending response into a closed channel (id={:?}), original request likely timed out",
+                            request_seq
+                        ),
+                    }
+                    None => {
+                        warn!("Response to nonexistent request #{}", res.request_seq);
+                        client_tx.send(Payload::Response(res)).expect("Failed to send");
+                    }
+                }
+
+                Ok(())
+            }
+            Payload::Request(Request {
+                ref command,
+                ref seq,
+                ..
+            }) => {
+                info!("<- DAP request {} #{}", command, seq);
+                client_tx.send(msg).expect("Failed to send");
+                Ok(())
+            }
+            Payload::Event(ref event) => {
+                info!("<- DAP event {:?}", event);
+                client_tx.send(msg).expect("Failed to send");
+                Ok(())
+            }
+        }
+    }
+
+    async fn recv(
+        transport: Arc<Self>,
+        mut server_stdout: Box<dyn AsyncBufRead + Unpin + Send>,
+        client_tx: UnboundedSender<Payload>,
+    ) {
+        let mut recv_buffer = String::new();
+        loop {
+            match Self::recv_server_message(&mut server_stdout, &mut recv_buffer).await {
+                Ok(msg) => {
+                    transport
+                        .process_server_message(&client_tx, msg)
+                        .await
+                        .unwrap();
+                }
+                Err(err) => {
+                    error!("err: <- {:?}", err);
+                    break;
+                }
+            }
+        }
+    }
+
+    async fn send(
+        transport: Arc<Self>,
+        mut server_stdin: Box<dyn AsyncWrite + Unpin + Send>,
+        mut client_rx: UnboundedReceiver<Request>,
+    ) {
+        while let Some(req) = client_rx.recv().await {
+            transport
+                .send_payload_to_server(&mut server_stdin, req)
+                .await
+                .unwrap()
+        }
+    }
+
+    async fn err(mut server_stderr: Box<dyn AsyncBufRead + Unpin + Send>) {
+        let mut recv_buffer = String::new();
+        loop {
+            match Self::recv_server_error(&mut server_stderr, &mut recv_buffer).await {
+                Ok(_) => {}
+                Err(err) => {
+                    error!("err: <- {:?}", err);
+                    break;
+                }
+            }
+        }
+    }
+}
diff --git a/helix-dap/src/types.rs b/helix-dap/src/types.rs
new file mode 100644
index 00000000..c2becf33
--- /dev/null
+++ b/helix-dap/src/types.rs
@@ -0,0 +1,686 @@
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+use std::path::PathBuf;
+
+#[derive(
+    Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Deserialize, Serialize,
+)]
+pub struct ThreadId(isize);
+
+impl std::fmt::Display for ThreadId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+pub trait Request {
+    type Arguments: serde::de::DeserializeOwned + serde::Serialize;
+    type Result: serde::de::DeserializeOwned + serde::Serialize;
+    const COMMAND: &'static str;
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ColumnDescriptor {
+    pub attribute_name: String,
+    pub label: String,
+    pub format: Option<String>,
+    #[serde(rename = "type")]
+    pub col_type: Option<String>,
+    pub width: Option<usize>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ExceptionBreakpointsFilter {
+    pub filter: String,
+    pub label: String,
+    pub description: Option<String>,
+    pub default: Option<bool>,
+    pub supports_condition: Option<bool>,
+    pub condition_description: Option<String>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct DebuggerCapabilities {
+    pub supports_configuration_done_request: Option<bool>,
+    pub supports_function_breakpoints: Option<bool>,
+    pub supports_conditional_breakpoints: Option<bool>,
+    pub supports_hit_conditional_breakpoints: Option<bool>,
+    pub supports_evaluate_for_hovers: Option<bool>,
+    pub supports_step_back: Option<bool>,
+    pub supports_set_variable: Option<bool>,
+    pub supports_restart_frame: Option<bool>,
+    pub supports_goto_targets_request: Option<bool>,
+    pub supports_step_in_targets_request: Option<bool>,
+    pub supports_completions_request: Option<bool>,
+    pub supports_modules_request: Option<bool>,
+    pub supports_restart_request: Option<bool>,
+    pub supports_exception_options: Option<bool>,
+    pub supports_value_formatting_options: Option<bool>,
+    pub supports_exception_info_request: Option<bool>,
+    pub support_terminate_debuggee: Option<bool>,
+    pub support_suspend_debuggee: Option<bool>,
+    pub supports_delayed_stack_trace_loading: Option<bool>,
+    pub supports_loaded_sources_request: Option<bool>,
+    pub supports_log_points: Option<bool>,
+    pub supports_terminate_threads_request: Option<bool>,
+    pub supports_set_expression: Option<bool>,
+    pub supports_terminate_request: Option<bool>,
+    pub supports_data_breakpoints: Option<bool>,
+    pub supports_read_memory_request: Option<bool>,
+    pub supports_write_memory_request: Option<bool>,
+    pub supports_disassemble_request: Option<bool>,
+    pub supports_cancel_request: Option<bool>,
+    pub supports_breakpoint_locations_request: Option<bool>,
+    pub supports_clipboard_context: Option<bool>,
+    pub supports_stepping_granularity: Option<bool>,
+    pub supports_instruction_breakpoints: Option<bool>,
+    pub supports_exception_filter_options: Option<bool>,
+    pub exception_breakpoint_filters: Option<Vec<ExceptionBreakpointsFilter>>,
+    pub completion_trigger_characters: Option<Vec<String>>,
+    pub additional_module_columns: Option<Vec<ColumnDescriptor>>,
+    pub supported_checksum_algorithms: Option<Vec<String>>,
+}
+
+impl std::ops::Deref for DebuggerCapabilities {
+    type Target = Option<bool>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.supports_exception_options
+    }
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Checksum {
+    pub algorithm: String,
+    pub checksum: String,
+}
+
+#[derive(Debug, Default, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Source {
+    pub name: Option<String>,
+    pub path: Option<PathBuf>,
+    pub source_reference: Option<usize>,
+    pub presentation_hint: Option<String>,
+    pub origin: Option<String>,
+    pub sources: Option<Vec<Source>>,
+    pub adapter_data: Option<Value>,
+    pub checksums: Option<Vec<Checksum>>,
+}
+
+#[derive(Debug, Default, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SourceBreakpoint {
+    pub line: usize,
+    pub column: Option<usize>,
+    pub condition: Option<String>,
+    pub hit_condition: Option<String>,
+    pub log_message: Option<String>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Breakpoint {
+    pub id: Option<usize>,
+    pub verified: bool,
+    pub message: Option<String>,
+    pub source: Option<Source>,
+    pub line: Option<usize>,
+    pub column: Option<usize>,
+    pub end_line: Option<usize>,
+    pub end_column: Option<usize>,
+    pub instruction_reference: Option<String>,
+    pub offset: Option<usize>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct StackFrameFormat {
+    pub parameters: Option<bool>,
+    pub parameter_types: Option<bool>,
+    pub parameter_names: Option<bool>,
+    pub parameter_values: Option<bool>,
+    pub line: Option<bool>,
+    pub module: Option<bool>,
+    pub include_all: Option<bool>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct StackFrame {
+    pub id: usize,
+    pub name: String,
+    pub source: Option<Source>,
+    pub line: usize,
+    pub column: usize,
+    pub end_line: Option<usize>,
+    pub end_column: Option<usize>,
+    pub can_restart: Option<bool>,
+    pub instruction_pointer_reference: Option<String>,
+    pub module_id: Option<Value>,
+    pub presentation_hint: Option<String>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Thread {
+    pub id: ThreadId,
+    pub name: String,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Scope {
+    pub name: String,
+    pub presentation_hint: Option<String>,
+    pub variables_reference: usize,
+    pub named_variables: Option<usize>,
+    pub indexed_variables: Option<usize>,
+    pub expensive: bool,
+    pub source: Option<Source>,
+    pub line: Option<usize>,
+    pub column: Option<usize>,
+    pub end_line: Option<usize>,
+    pub end_column: Option<usize>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ValueFormat {
+    pub hex: Option<bool>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct VariablePresentationHint {
+    pub kind: Option<String>,
+    pub attributes: Option<Vec<String>>,
+    pub visibility: Option<String>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Variable {
+    pub name: String,
+    pub value: String,
+    #[serde(rename = "type")]
+    pub data_type: Option<String>,
+    pub presentation_hint: Option<VariablePresentationHint>,
+    pub evaluate_name: Option<String>,
+    pub variables_reference: usize,
+    pub named_variables: Option<usize>,
+    pub indexed_variables: Option<usize>,
+    pub memory_reference: Option<String>,
+}
+
+#[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Module {
+    pub id: String, // TODO: || number
+    pub name: String,
+    pub path: Option<PathBuf>,
+    pub is_optimized: Option<bool>,
+    pub is_user_code: Option<bool>,
+    pub version: Option<String>,
+    pub symbol_status: Option<String>,
+    pub symbol_file_path: Option<String>,
+    pub date_time_stamp: Option<String>,
+    pub address_range: Option<String>,
+}
+
+pub mod requests {
+    use super::*;
+    #[derive(Debug, Default, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct InitializeArguments {
+        #[serde(rename = "clientID")]
+        pub client_id: Option<String>,
+        pub client_name: Option<String>,
+        #[serde(rename = "adapterID")]
+        pub adapter_id: String,
+        pub locale: Option<String>,
+        #[serde(rename = "linesStartAt1")]
+        pub lines_start_at_one: Option<bool>,
+        #[serde(rename = "columnsStartAt1")]
+        pub columns_start_at_one: Option<bool>,
+        pub path_format: Option<String>,
+        pub supports_variable_type: Option<bool>,
+        pub supports_variable_paging: Option<bool>,
+        pub supports_run_in_terminal_request: Option<bool>,
+        pub supports_memory_references: Option<bool>,
+        pub supports_progress_reporting: Option<bool>,
+        pub supports_invalidated_event: Option<bool>,
+    }
+
+    #[derive(Debug)]
+    pub enum Initialize {}
+
+    impl Request for Initialize {
+        type Arguments = InitializeArguments;
+        type Result = DebuggerCapabilities;
+        const COMMAND: &'static str = "initialize";
+    }
+
+    #[derive(Debug)]
+    pub enum Launch {}
+
+    impl Request for Launch {
+        type Arguments = Value;
+        type Result = Value;
+        const COMMAND: &'static str = "launch";
+    }
+
+    #[derive(Debug)]
+    pub enum Attach {}
+
+    impl Request for Attach {
+        type Arguments = Value;
+        type Result = Value;
+        const COMMAND: &'static str = "attach";
+    }
+
+    #[derive(Debug)]
+    pub enum Disconnect {}
+
+    impl Request for Disconnect {
+        type Arguments = ();
+        type Result = ();
+        const COMMAND: &'static str = "disconnect";
+    }
+
+    #[derive(Debug)]
+    pub enum ConfigurationDone {}
+
+    impl Request for ConfigurationDone {
+        type Arguments = ();
+        type Result = ();
+        const COMMAND: &'static str = "configurationDone";
+    }
+
+    #[derive(Debug, Default, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct SetBreakpointsArguments {
+        pub source: Source,
+        pub breakpoints: Option<Vec<SourceBreakpoint>>,
+        // lines is deprecated
+        pub source_modified: Option<bool>,
+    }
+
+    #[derive(Debug, Default, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct SetBreakpointsResponse {
+        pub breakpoints: Option<Vec<Breakpoint>>,
+    }
+
+    #[derive(Debug)]
+    pub enum SetBreakpoints {}
+
+    impl Request for SetBreakpoints {
+        type Arguments = SetBreakpointsArguments;
+        type Result = SetBreakpointsResponse;
+        const COMMAND: &'static str = "setBreakpoints";
+    }
+
+    #[derive(Debug, Default, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct ContinueArguments {
+        pub thread_id: ThreadId,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct ContinueResponse {
+        pub all_threads_continued: Option<bool>,
+    }
+
+    #[derive(Debug)]
+    pub enum Continue {}
+
+    impl Request for Continue {
+        type Arguments = ContinueArguments;
+        type Result = ContinueResponse;
+        const COMMAND: &'static str = "continue";
+    }
+
+    #[derive(Debug, Default, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct StackTraceArguments {
+        pub thread_id: ThreadId,
+        pub start_frame: Option<usize>,
+        pub levels: Option<usize>,
+        pub format: Option<StackFrameFormat>,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct StackTraceResponse {
+        pub total_frames: Option<usize>,
+        pub stack_frames: Vec<StackFrame>,
+    }
+
+    #[derive(Debug)]
+    pub enum StackTrace {}
+
+    impl Request for StackTrace {
+        type Arguments = StackTraceArguments;
+        type Result = StackTraceResponse;
+        const COMMAND: &'static str = "stackTrace";
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct ThreadsResponse {
+        pub threads: Vec<Thread>,
+    }
+
+    #[derive(Debug)]
+    pub enum Threads {}
+
+    impl Request for Threads {
+        type Arguments = ();
+        type Result = ThreadsResponse;
+        const COMMAND: &'static str = "threads";
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct ScopesArguments {
+        pub frame_id: usize,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct ScopesResponse {
+        pub scopes: Vec<Scope>,
+    }
+
+    #[derive(Debug)]
+    pub enum Scopes {}
+
+    impl Request for Scopes {
+        type Arguments = ScopesArguments;
+        type Result = ScopesResponse;
+        const COMMAND: &'static str = "scopes";
+    }
+
+    #[derive(Debug, Default, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct VariablesArguments {
+        pub variables_reference: usize,
+        pub filter: Option<String>,
+        pub start: Option<usize>,
+        pub count: Option<usize>,
+        pub format: Option<ValueFormat>,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct VariablesResponse {
+        pub variables: Vec<Variable>,
+    }
+
+    #[derive(Debug)]
+    pub enum Variables {}
+
+    impl Request for Variables {
+        type Arguments = VariablesArguments;
+        type Result = VariablesResponse;
+        const COMMAND: &'static str = "variables";
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct StepInArguments {
+        pub thread_id: ThreadId,
+        pub target_id: Option<usize>,
+        pub granularity: Option<String>,
+    }
+
+    #[derive(Debug)]
+    pub enum StepIn {}
+
+    impl Request for StepIn {
+        type Arguments = StepInArguments;
+        type Result = ();
+        const COMMAND: &'static str = "stepIn";
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct StepOutArguments {
+        pub thread_id: ThreadId,
+        pub granularity: Option<String>,
+    }
+
+    #[derive(Debug)]
+    pub enum StepOut {}
+
+    impl Request for StepOut {
+        type Arguments = StepOutArguments;
+        type Result = ();
+        const COMMAND: &'static str = "stepOut";
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct NextArguments {
+        pub thread_id: ThreadId,
+        pub granularity: Option<String>,
+    }
+
+    #[derive(Debug)]
+    pub enum Next {}
+
+    impl Request for Next {
+        type Arguments = NextArguments;
+        type Result = ();
+        const COMMAND: &'static str = "next";
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct PauseArguments {
+        pub thread_id: ThreadId,
+    }
+
+    #[derive(Debug)]
+    pub enum Pause {}
+
+    impl Request for Pause {
+        type Arguments = PauseArguments;
+        type Result = ();
+        const COMMAND: &'static str = "pause";
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct EvaluateArguments {
+        pub expression: String,
+        pub frame_id: Option<usize>,
+        pub context: Option<String>,
+        pub format: Option<ValueFormat>,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct EvaluateResponse {
+        pub result: String,
+        #[serde(rename = "type")]
+        pub data_type: Option<String>,
+        pub presentation_hint: Option<VariablePresentationHint>,
+        pub variables_reference: usize,
+        pub named_variables: Option<usize>,
+        pub indexed_variables: Option<usize>,
+        pub memory_reference: Option<String>,
+    }
+
+    #[derive(Debug)]
+    pub enum Evaluate {}
+
+    impl Request for Evaluate {
+        type Arguments = EvaluateArguments;
+        type Result = EvaluateResponse;
+        const COMMAND: &'static str = "evaluate";
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct SetExceptionBreakpointsArguments {
+        pub filters: Vec<String>,
+        // pub filterOptions: Option<Vec<ExceptionFilterOptions>>, // needs capability
+        // pub exceptionOptions: Option<Vec<ExceptionOptions>>, // needs capability
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct SetExceptionBreakpointsResponse {
+        pub breakpoints: Option<Vec<Breakpoint>>,
+    }
+
+    #[derive(Debug)]
+    pub enum SetExceptionBreakpoints {}
+
+    impl Request for SetExceptionBreakpoints {
+        type Arguments = SetExceptionBreakpointsArguments;
+        type Result = SetExceptionBreakpointsResponse;
+        const COMMAND: &'static str = "setExceptionBreakpoints";
+    }
+}
+
+// Events
+
+pub mod events {
+    use super::*;
+
+    #[derive(Debug, Clone, Serialize, Deserialize)]
+    #[serde(rename_all = "camelCase")]
+    #[serde(tag = "event", content = "body")]
+    // seq is omitted as unused and is not sent by some implementations
+    pub enum Event {
+        Initialized,
+        Stopped(Stopped),
+        Continued(Continued),
+        Exited(Exited),
+        Terminated(Option<Terminated>),
+        Thread(Thread),
+        Output(Output),
+        Breakpoint(Breakpoint),
+        Module(Module),
+        LoadedSource(LoadedSource),
+        Process(Process),
+        Capabilities(Capabilities),
+        // ProgressStart(),
+        // ProgressUpdate(),
+        // ProgressEnd(),
+        // Invalidated(),
+        Memory(Memory),
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Stopped {
+        pub reason: String,
+        pub description: Option<String>,
+        pub thread_id: Option<ThreadId>,
+        pub preserve_focus_hint: Option<bool>,
+        pub text: Option<String>,
+        pub all_threads_stopped: Option<bool>,
+        pub hit_breakpoint_ids: Option<Vec<usize>>,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Continued {
+        pub thread_id: ThreadId,
+        pub all_threads_continued: Option<bool>,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Exited {
+        pub exit_code: usize,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Terminated {
+        pub restart: Option<Value>,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Thread {
+        pub reason: String,
+        pub thread_id: ThreadId,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Output {
+        pub output: String,
+        pub category: Option<String>,
+        pub group: Option<String>,
+        pub line: Option<usize>,
+        pub column: Option<usize>,
+        pub variables_reference: Option<usize>,
+        pub source: Option<Source>,
+        pub data: Option<Value>,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Breakpoint {
+        pub reason: String,
+        pub breakpoint: super::Breakpoint,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Module {
+        pub reason: String,
+        pub module: super::Module,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct LoadedSource {
+        pub reason: String,
+        pub source: super::Source,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Process {
+        pub name: String,
+        pub system_process_id: Option<usize>,
+        pub is_local_process: Option<bool>,
+        pub start_method: Option<String>, // TODO: use enum
+        pub pointer_size: Option<usize>,
+    }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Capabilities {
+        pub capabilities: super::DebuggerCapabilities,
+    }
+
+    // #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    // #[serde(rename_all = "camelCase")]
+    // pub struct Invalidated {
+    // pub areas: Vec<InvalidatedArea>,
+    // pub thread_id: Option<ThreadId>,
+    // pub stack_frame_id: Option<usize>,
+    // }
+
+    #[derive(Debug, PartialEq, Clone, Deserialize, Serialize)]
+    #[serde(rename_all = "camelCase")]
+    pub struct Memory {
+        pub memory_reference: String,
+        pub offset: usize,
+        pub count: usize,
+    }
+}