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denoland-deno/cli/tools/repl.rs

800 lines
22 KiB
Rust

// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
use crate::ast::transpile;
use crate::ast::ImportsNotUsedAsValues;
use crate::colors;
use crate::program_state::ProgramState;
use deno_ast::swc::parser::error::SyntaxError;
use deno_ast::swc::parser::token::{Token, Word};
use deno_core::error::AnyError;
use deno_core::futures::FutureExt;
use deno_core::parking_lot::Mutex;
use deno_core::serde_json::json;
use deno_core::serde_json::Value;
use deno_core::LocalInspectorSession;
use deno_runtime::worker::MainWorker;
use rustyline::completion::Completer;
use rustyline::error::ReadlineError;
use rustyline::highlight::Highlighter;
use rustyline::validate::ValidationContext;
use rustyline::validate::ValidationResult;
use rustyline::validate::Validator;
use rustyline::CompletionType;
use rustyline::Config;
use rustyline::Context;
use rustyline::Editor;
use rustyline_derive::{Helper, Hinter};
use std::borrow::Cow;
use std::cell::RefCell;
use std::path::PathBuf;
use std::sync::Arc;
use tokio::sync::mpsc::channel;
use tokio::sync::mpsc::unbounded_channel;
use tokio::sync::mpsc::Receiver;
use tokio::sync::mpsc::Sender;
use tokio::sync::mpsc::UnboundedReceiver;
use tokio::sync::mpsc::UnboundedSender;
// Provides helpers to the editor like validation for multi-line edits, completion candidates for
// tab completion.
#[derive(Helper, Hinter)]
struct EditorHelper {
context_id: u64,
message_tx: Sender<(String, Option<Value>)>,
response_rx: RefCell<UnboundedReceiver<Result<Value, AnyError>>>,
}
impl EditorHelper {
pub fn get_global_lexical_scope_names(&self) -> Vec<String> {
let evaluate_response = self
.post_message(
"Runtime.globalLexicalScopeNames",
Some(json!({
"executionContextId": self.context_id,
})),
)
.unwrap();
evaluate_response
.get("names")
.unwrap()
.as_array()
.unwrap()
.iter()
.map(|n| n.as_str().unwrap().to_string())
.collect()
}
pub fn get_expression_property_names(&self, expr: &str) -> Vec<String> {
// try to get the properties from the expression
if let Some(properties) = self.get_object_expr_properties(expr) {
return properties;
}
// otherwise fall back to the prototype
let expr_type = self.get_expression_type(expr);
let object_expr = match expr_type.as_deref() {
// possibilities: https://chromedevtools.github.io/devtools-protocol/v8/Runtime/#type-RemoteObject
Some("object") => "Object.prototype",
Some("function") => "Function.prototype",
Some("string") => "String.prototype",
Some("boolean") => "Boolean.prototype",
Some("bigint") => "BigInt.prototype",
Some("number") => "Number.prototype",
_ => return Vec::new(), // undefined, symbol, and unhandled
};
self
.get_object_expr_properties(object_expr)
.unwrap_or_else(Vec::new)
}
fn get_expression_type(&self, expr: &str) -> Option<String> {
self
.evaluate_expression(expr)?
.get("result")?
.get("type")?
.as_str()
.map(|s| s.to_string())
}
fn get_object_expr_properties(
&self,
object_expr: &str,
) -> Option<Vec<String>> {
let evaluate_result = self.evaluate_expression(object_expr)?;
let object_id = evaluate_result.get("result")?.get("objectId")?;
let get_properties_response = self
.post_message(
"Runtime.getProperties",
Some(json!({
"objectId": object_id,
})),
)
.ok()?;
Some(
get_properties_response
.get("result")?
.as_array()
.unwrap()
.iter()
.map(|r| r.get("name").unwrap().as_str().unwrap().to_string())
.collect(),
)
}
fn evaluate_expression(&self, expr: &str) -> Option<Value> {
let evaluate_response = self
.post_message(
"Runtime.evaluate",
Some(json!({
"contextId": self.context_id,
"expression": expr,
"throwOnSideEffect": true,
"timeout": 200,
})),
)
.ok()?;
if evaluate_response.get("exceptionDetails").is_some() {
None
} else {
Some(evaluate_response)
}
}
fn post_message(
&self,
method: &str,
params: Option<Value>,
) -> Result<Value, AnyError> {
self
.message_tx
.blocking_send((method.to_string(), params))?;
self.response_rx.borrow_mut().blocking_recv().unwrap()
}
}
fn is_word_boundary(c: char) -> bool {
if c == '.' {
false
} else {
char::is_ascii_whitespace(&c) || char::is_ascii_punctuation(&c)
}
}
fn get_expr_from_line_at_pos(line: &str, cursor_pos: usize) -> &str {
let start = line[..cursor_pos]
.rfind(is_word_boundary)
.map_or_else(|| 0, |i| i);
let end = line[cursor_pos..]
.rfind(is_word_boundary)
.map_or_else(|| cursor_pos, |i| cursor_pos + i);
let word = &line[start..end];
let word = word.strip_prefix(is_word_boundary).unwrap_or(word);
let word = word.strip_suffix(is_word_boundary).unwrap_or(word);
word
}
impl Completer for EditorHelper {
type Candidate = String;
fn complete(
&self,
line: &str,
pos: usize,
_ctx: &Context<'_>,
) -> Result<(usize, Vec<String>), ReadlineError> {
let expr = get_expr_from_line_at_pos(line, pos);
// check if the expression is in the form `obj.prop`
if let Some(index) = expr.rfind('.') {
let sub_expr = &expr[..index];
let prop_name = &expr[index + 1..];
let candidates = self
.get_expression_property_names(sub_expr)
.into_iter()
.filter(|n| !n.starts_with("Symbol(") && n.starts_with(prop_name))
.collect();
Ok((pos - prop_name.len(), candidates))
} else {
// combine results of declarations and globalThis properties
let mut candidates = self
.get_expression_property_names("globalThis")
.into_iter()
.chain(self.get_global_lexical_scope_names())
.filter(|n| n.starts_with(expr))
.collect::<Vec<_>>();
// sort and remove duplicates
candidates.sort();
candidates.dedup(); // make sure to sort first
Ok((pos - expr.len(), candidates))
}
}
}
impl Validator for EditorHelper {
fn validate(
&self,
ctx: &mut ValidationContext,
) -> Result<ValidationResult, ReadlineError> {
let mut stack: Vec<Token> = Vec::new();
let mut in_template = false;
for item in deno_ast::lex(ctx.input(), deno_ast::MediaType::TypeScript) {
if let deno_ast::TokenOrComment::Token(token) = item.inner {
match token {
Token::BackQuote => in_template = !in_template,
Token::LParen
| Token::LBracket
| Token::LBrace
| Token::DollarLBrace => stack.push(token),
Token::RParen | Token::RBracket | Token::RBrace => {
match (stack.pop(), token) {
(Some(Token::LParen), Token::RParen)
| (Some(Token::LBracket), Token::RBracket)
| (Some(Token::LBrace), Token::RBrace)
| (Some(Token::DollarLBrace), Token::RBrace) => {}
(Some(left), _) => {
return Ok(ValidationResult::Invalid(Some(format!(
"Mismatched pairs: {:?} is not properly closed",
left
))))
}
(None, _) => {
// While technically invalid when unpaired, it should be V8's task to output error instead.
// Thus marked as valid with no info.
return Ok(ValidationResult::Valid(None));
}
}
}
Token::Error(error) => {
match error.kind() {
// If there is unterminated template, it continues to read input.
SyntaxError::UnterminatedTpl => {}
_ => {
// If it failed parsing, it should be V8's task to output error instead.
// Thus marked as valid with no info.
return Ok(ValidationResult::Valid(None));
}
}
}
_ => {}
}
}
}
if !stack.is_empty() || in_template {
return Ok(ValidationResult::Incomplete);
}
Ok(ValidationResult::Valid(None))
}
}
impl Highlighter for EditorHelper {
fn highlight_hint<'h>(&self, hint: &'h str) -> Cow<'h, str> {
hint.into()
}
fn highlight_candidate<'c>(
&self,
candidate: &'c str,
completion: rustyline::CompletionType,
) -> Cow<'c, str> {
if completion == CompletionType::List {
candidate.into()
} else {
self.highlight(candidate, 0)
}
}
fn highlight_char(&self, line: &str, _: usize) -> bool {
!line.is_empty()
}
fn highlight<'l>(&self, line: &'l str, _: usize) -> Cow<'l, str> {
let mut out_line = String::from(line);
for item in deno_ast::lex(line, deno_ast::MediaType::TypeScript) {
// Adding color adds more bytes to the string,
// so an offset is needed to stop spans falling out of sync.
let offset = out_line.len() - line.len();
let span = std::ops::Range {
start: item.span.lo.0 as usize,
end: item.span.hi.0 as usize,
};
out_line.replace_range(
span.start + offset..span.end + offset,
&match item.inner {
deno_ast::TokenOrComment::Token(token) => match token {
Token::Str { .. } | Token::Template { .. } | Token::BackQuote => {
colors::green(&line[span]).to_string()
}
Token::Regex(_, _) => colors::red(&line[span]).to_string(),
Token::Num(_) | Token::BigInt(_) => {
colors::yellow(&line[span]).to_string()
}
Token::Word(word) => match word {
Word::True | Word::False | Word::Null => {
colors::yellow(&line[span]).to_string()
}
Word::Keyword(_) => colors::cyan(&line[span]).to_string(),
Word::Ident(ident) => {
if ident == *"undefined" {
colors::gray(&line[span]).to_string()
} else if ident == *"Infinity" || ident == *"NaN" {
colors::yellow(&line[span]).to_string()
} else if ident == *"async" || ident == *"of" {
colors::cyan(&line[span]).to_string()
} else {
line[span].to_string()
}
}
},
_ => line[span].to_string(),
},
deno_ast::TokenOrComment::Comment { .. } => {
colors::gray(&line[span]).to_string()
}
},
);
}
out_line.into()
}
}
#[derive(Clone)]
struct ReplEditor {
inner: Arc<Mutex<Editor<EditorHelper>>>,
history_file_path: PathBuf,
}
impl ReplEditor {
pub fn new(helper: EditorHelper, history_file_path: PathBuf) -> Self {
let editor_config = Config::builder()
.completion_type(CompletionType::List)
.build();
let mut editor = Editor::with_config(editor_config);
editor.set_helper(Some(helper));
editor.load_history(&history_file_path).unwrap_or(());
ReplEditor {
inner: Arc::new(Mutex::new(editor)),
history_file_path,
}
}
pub fn readline(&self) -> Result<String, ReadlineError> {
self.inner.lock().readline("> ")
}
pub fn add_history_entry(&self, entry: String) {
self.inner.lock().add_history_entry(entry);
}
pub fn save_history(&self) -> Result<(), AnyError> {
std::fs::create_dir_all(self.history_file_path.parent().unwrap())?;
self.inner.lock().save_history(&self.history_file_path)?;
Ok(())
}
}
static PRELUDE: &str = r#"
Object.defineProperty(globalThis, "_", {
configurable: true,
get: () => Deno[Deno.internal].lastEvalResult,
set: (value) => {
Object.defineProperty(globalThis, "_", {
value: value,
writable: true,
enumerable: true,
configurable: true,
});
console.log("Last evaluation result is no longer saved to _.");
},
});
Object.defineProperty(globalThis, "_error", {
configurable: true,
get: () => Deno[Deno.internal].lastThrownError,
set: (value) => {
Object.defineProperty(globalThis, "_error", {
value: value,
writable: true,
enumerable: true,
configurable: true,
});
console.log("Last thrown error is no longer saved to _error.");
},
});
"#;
enum EvaluationOutput {
Value(String),
Error(String),
}
impl std::fmt::Display for EvaluationOutput {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
EvaluationOutput::Value(value) => f.write_str(value),
EvaluationOutput::Error(value) => f.write_str(value),
}
}
}
struct ReplSession {
worker: MainWorker,
session: LocalInspectorSession,
pub context_id: u64,
}
impl ReplSession {
pub async fn initialize(mut worker: MainWorker) -> Result<Self, AnyError> {
let mut session = worker.create_inspector_session().await;
worker
.with_event_loop(
session.post_message("Runtime.enable", None).boxed_local(),
)
.await?;
// Enabling the runtime domain will always send trigger one executionContextCreated for each
// context the inspector knows about so we grab the execution context from that since
// our inspector does not support a default context (0 is an invalid context id).
let mut context_id: u64 = 0;
for notification in session.notifications() {
let method = notification.get("method").unwrap().as_str().unwrap();
let params = notification.get("params").unwrap();
if method == "Runtime.executionContextCreated" {
context_id = params
.get("context")
.unwrap()
.get("id")
.unwrap()
.as_u64()
.unwrap();
}
}
let mut repl_session = ReplSession {
worker,
session,
context_id,
};
// inject prelude
repl_session.evaluate_expression(PRELUDE).await?;
Ok(repl_session)
}
pub async fn is_closing(&mut self) -> Result<bool, AnyError> {
let closed = self
.evaluate_expression("(globalThis.closed)")
.await?
.get("result")
.unwrap()
.get("value")
.unwrap()
.as_bool()
.unwrap();
Ok(closed)
}
pub async fn post_message_with_event_loop(
&mut self,
method: &str,
params: Option<Value>,
) -> Result<Value, AnyError> {
self
.worker
.with_event_loop(self.session.post_message(method, params).boxed_local())
.await
}
pub async fn run_event_loop(&mut self) -> Result<(), AnyError> {
self.worker.run_event_loop(true).await
}
pub async fn evaluate_line_and_get_output(
&mut self,
line: &str,
) -> Result<EvaluationOutput, AnyError> {
match self.evaluate_line_with_object_wrapping(line).await {
Ok(evaluate_response) => {
let evaluate_result = evaluate_response.get("result").unwrap();
let evaluate_exception_details =
evaluate_response.get("exceptionDetails");
if evaluate_exception_details.is_some() {
self.set_last_thrown_error(evaluate_result).await?;
} else {
self.set_last_eval_result(evaluate_result).await?;
}
let value = self.get_eval_value(evaluate_result).await?;
Ok(match evaluate_exception_details {
Some(_) => EvaluationOutput::Error(format!("Uncaught {}", value)),
None => EvaluationOutput::Value(value),
})
}
Err(err) => {
// handle a parsing diagnostic
match err.downcast_ref::<deno_ast::Diagnostic>() {
Some(diagnostic) => Ok(EvaluationOutput::Error(format!(
"{}: {} at {}:{}",
colors::red("parse error"),
diagnostic.message,
diagnostic.display_position.line_number,
diagnostic.display_position.column_number,
))),
None => Err(err),
}
}
}
}
async fn evaluate_line_with_object_wrapping(
&mut self,
line: &str,
) -> Result<Value, AnyError> {
// It is a bit unexpected that { "foo": "bar" } is interpreted as a block
// statement rather than an object literal so we interpret it as an expression statement
// to match the behavior found in a typical prompt including browser developer tools.
let wrapped_line = if line.trim_start().starts_with('{')
&& !line.trim_end().ends_with(';')
{
format!("({})", &line)
} else {
line.to_string()
};
let evaluate_response = self.evaluate_ts_expression(&wrapped_line).await?;
// If that fails, we retry it without wrapping in parens letting the error bubble up to the
// user if it is still an error.
let evaluate_response =
if evaluate_response.get("exceptionDetails").is_some()
&& wrapped_line != line
{
self.evaluate_ts_expression(line).await?
} else {
evaluate_response
};
Ok(evaluate_response)
}
async fn set_last_thrown_error(
&mut self,
error: &Value,
) -> Result<(), AnyError> {
self.post_message_with_event_loop(
"Runtime.callFunctionOn",
Some(json!({
"executionContextId": self.context_id,
"functionDeclaration": "function (object) { Deno[Deno.internal].lastThrownError = object; }",
"arguments": [
error,
],
})),
).await?;
Ok(())
}
async fn set_last_eval_result(
&mut self,
evaluate_result: &Value,
) -> Result<(), AnyError> {
self.post_message_with_event_loop(
"Runtime.callFunctionOn",
Some(json!({
"executionContextId": self.context_id,
"functionDeclaration": "function (object) { Deno[Deno.internal].lastEvalResult = object; }",
"arguments": [
evaluate_result,
],
})),
).await?;
Ok(())
}
pub async fn get_eval_value(
&mut self,
evaluate_result: &Value,
) -> Result<String, AnyError> {
// TODO(caspervonb) we should investigate using previews here but to keep things
// consistent with the previous implementation we just get the preview result from
// Deno.inspectArgs.
let inspect_response = self.post_message_with_event_loop(
"Runtime.callFunctionOn",
Some(json!({
"executionContextId": self.context_id,
"functionDeclaration": r#"function (object) {
try {
return Deno[Deno.internal].inspectArgs(["%o", object], { colors: !Deno.noColor });
} catch (err) {
return Deno[Deno.internal].inspectArgs(["%o", err]);
}
}"#,
"arguments": [
evaluate_result,
],
})),
).await?;
let inspect_result = inspect_response.get("result").unwrap();
let value = inspect_result.get("value").unwrap().as_str().unwrap();
Ok(value.to_string())
}
async fn evaluate_ts_expression(
&mut self,
expression: &str,
) -> Result<Value, AnyError> {
let parsed_module = deno_ast::parse_module(deno_ast::ParseParams {
specifier: "repl.ts".to_string(),
source: deno_ast::SourceTextInfo::from_string(expression.to_string()),
media_type: deno_ast::MediaType::TypeScript,
capture_tokens: false,
maybe_syntax: None,
})?;
let transpiled_src = transpile(
&parsed_module,
&crate::ast::EmitOptions {
emit_metadata: false,
source_map: false,
inline_source_map: false,
imports_not_used_as_values: ImportsNotUsedAsValues::Preserve,
// JSX is not supported in the REPL
transform_jsx: false,
jsx_factory: "React.createElement".into(),
jsx_fragment_factory: "React.Fragment".into(),
repl_imports: true,
},
)?
.0;
self
.evaluate_expression(&format!(
"'use strict'; void 0;\n{}",
transpiled_src
))
.await
}
async fn evaluate_expression(
&mut self,
expression: &str,
) -> Result<Value, AnyError> {
self
.post_message_with_event_loop(
"Runtime.evaluate",
Some(json!({
"expression": expression,
"contextId": self.context_id,
"replMode": true,
})),
)
.await
}
}
async fn read_line_and_poll(
repl_session: &mut ReplSession,
message_rx: &mut Receiver<(String, Option<Value>)>,
response_tx: &UnboundedSender<Result<Value, AnyError>>,
editor: ReplEditor,
) -> Result<String, ReadlineError> {
let mut line_fut = tokio::task::spawn_blocking(move || editor.readline());
let mut poll_worker = true;
loop {
tokio::select! {
result = &mut line_fut => {
return result.unwrap();
}
result = message_rx.recv() => {
if let Some((method, params)) = result {
let result = repl_session
.post_message_with_event_loop(&method, params)
.await;
response_tx.send(result).unwrap();
}
poll_worker = true;
},
_ = repl_session.run_event_loop(), if poll_worker => {
poll_worker = false;
}
}
}
}
pub async fn run(
program_state: &ProgramState,
worker: MainWorker,
maybe_eval: Option<String>,
) -> Result<(), AnyError> {
let mut repl_session = ReplSession::initialize(worker).await?;
let (message_tx, mut message_rx) = channel(1);
let (response_tx, response_rx) = unbounded_channel();
let helper = EditorHelper {
context_id: repl_session.context_id,
message_tx,
response_rx: RefCell::new(response_rx),
};
let history_file_path = program_state.dir.root.join("deno_history.txt");
let editor = ReplEditor::new(helper, history_file_path);
if let Some(eval) = maybe_eval {
let output = repl_session.evaluate_line_and_get_output(&eval).await?;
// only output errors
if let EvaluationOutput::Error(error_text) = output {
println!("error in --eval flag. {}", error_text);
}
}
println!("Deno {}", crate::version::deno());
println!("exit using ctrl+d or close()");
loop {
let line = read_line_and_poll(
&mut repl_session,
&mut message_rx,
&response_tx,
editor.clone(),
)
.await;
match line {
Ok(line) => {
let output = repl_session.evaluate_line_and_get_output(&line).await?;
// We check for close and break here instead of making it a loop condition to get
// consistent behavior in when the user evaluates a call to close().
if repl_session.is_closing().await? {
break;
}
println!("{}", output);
editor.add_history_entry(line);
}
Err(ReadlineError::Interrupted) => {
println!("exit using ctrl+d or close()");
continue;
}
Err(ReadlineError::Eof) => {
break;
}
Err(err) => {
println!("Error: {:?}", err);
break;
}
}
}
editor.save_history()?;
Ok(())
}