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denoland-deno/cli/ast.rs
2020-12-22 00:57:03 +01:00

716 lines
20 KiB
Rust

// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
use crate::media_type::MediaType;
use crate::tsc_config;
use deno_core::error::AnyError;
use deno_core::serde_json;
use deno_core::ModuleSpecifier;
use std::error::Error;
use std::fmt;
use std::ops::Range;
use std::rc::Rc;
use std::sync::Arc;
use std::sync::RwLock;
use swc_common::chain;
use swc_common::comments::Comment;
use swc_common::comments::CommentKind;
use swc_common::comments::SingleThreadedComments;
use swc_common::errors::Diagnostic;
use swc_common::errors::DiagnosticBuilder;
use swc_common::errors::Emitter;
use swc_common::errors::Handler;
use swc_common::errors::HandlerFlags;
use swc_common::FileName;
use swc_common::Globals;
use swc_common::Loc;
use swc_common::SourceFile;
use swc_common::SourceMap;
use swc_common::Span;
use swc_ecmascript::ast::Module;
use swc_ecmascript::ast::Program;
use swc_ecmascript::codegen::text_writer::JsWriter;
use swc_ecmascript::codegen::Node;
use swc_ecmascript::dep_graph::analyze_dependencies;
use swc_ecmascript::dep_graph::DependencyDescriptor;
use swc_ecmascript::parser::lexer::Lexer;
use swc_ecmascript::parser::token::Token;
use swc_ecmascript::parser::EsConfig;
use swc_ecmascript::parser::JscTarget;
use swc_ecmascript::parser::StringInput;
use swc_ecmascript::parser::Syntax;
use swc_ecmascript::parser::TsConfig;
use swc_ecmascript::transforms::fixer;
use swc_ecmascript::transforms::helpers;
use swc_ecmascript::transforms::hygiene;
use swc_ecmascript::transforms::pass::Optional;
use swc_ecmascript::transforms::proposals;
use swc_ecmascript::transforms::react;
use swc_ecmascript::transforms::typescript;
use swc_ecmascript::visit::FoldWith;
static TARGET: JscTarget = JscTarget::Es2020;
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct Location {
pub filename: String,
pub line: usize,
pub col: usize,
}
impl Into<Location> for swc_common::Loc {
fn into(self) -> Location {
use swc_common::FileName::*;
let filename = match &self.file.name {
Real(path_buf) => path_buf.to_string_lossy().to_string(),
Custom(str_) => str_.to_string(),
_ => panic!("invalid filename"),
};
Location {
filename,
line: self.line,
col: self.col_display,
}
}
}
impl Into<ModuleSpecifier> for Location {
fn into(self) -> ModuleSpecifier {
ModuleSpecifier::resolve_url_or_path(&self.filename).unwrap()
}
}
impl std::fmt::Display for Location {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(f, "{}:{}:{}", self.filename, self.line, self.col)
}
}
/// A buffer for collecting diagnostic messages from the AST parser.
#[derive(Debug)]
pub struct DiagnosticBuffer(Vec<String>);
impl Error for DiagnosticBuffer {}
impl fmt::Display for DiagnosticBuffer {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let s = self.0.join(",");
f.pad(&s)
}
}
impl DiagnosticBuffer {
pub fn from_error_buffer<F>(error_buffer: ErrorBuffer, get_loc: F) -> Self
where
F: Fn(Span) -> Loc,
{
let s = error_buffer.0.read().unwrap().clone();
let diagnostics = s
.iter()
.map(|d| {
let mut msg = d.message();
if let Some(span) = d.span.primary_span() {
let loc = get_loc(span);
let file_name = match &loc.file.name {
FileName::Custom(n) => n,
_ => unreachable!(),
};
msg = format!(
"{} at {}:{}:{}",
msg, file_name, loc.line, loc.col_display
);
}
msg
})
.collect::<Vec<String>>();
Self(diagnostics)
}
}
/// A buffer for collecting errors from the AST parser.
#[derive(Debug, Clone)]
pub struct ErrorBuffer(Arc<RwLock<Vec<Diagnostic>>>);
impl ErrorBuffer {
pub fn new() -> Self {
Self(Arc::new(RwLock::new(Vec::new())))
}
}
impl Emitter for ErrorBuffer {
fn emit(&mut self, db: &DiagnosticBuilder) {
self.0.write().unwrap().push((**db).clone());
}
}
fn get_es_config(jsx: bool) -> EsConfig {
EsConfig {
class_private_methods: true,
class_private_props: true,
class_props: true,
dynamic_import: true,
export_default_from: true,
export_namespace_from: true,
import_meta: true,
jsx,
nullish_coalescing: true,
num_sep: true,
optional_chaining: true,
top_level_await: true,
..EsConfig::default()
}
}
fn get_ts_config(tsx: bool, dts: bool) -> TsConfig {
TsConfig {
decorators: true,
dts,
dynamic_import: true,
tsx,
..TsConfig::default()
}
}
pub fn get_syntax(media_type: &MediaType) -> Syntax {
match media_type {
MediaType::JavaScript => Syntax::Es(get_es_config(false)),
MediaType::JSX => Syntax::Es(get_es_config(true)),
MediaType::TypeScript => Syntax::Typescript(get_ts_config(false, false)),
MediaType::Dts => Syntax::Typescript(get_ts_config(false, true)),
MediaType::TSX => Syntax::Typescript(get_ts_config(true, false)),
_ => Syntax::Es(get_es_config(false)),
}
}
/// Options which can be adjusted when transpiling a module.
#[derive(Debug, Clone)]
pub struct EmitOptions {
/// Indicate if JavaScript is being checked/transformed as well, or if it is
/// only TypeScript.
pub check_js: bool,
/// When emitting a legacy decorator, also emit experimental decorator meta
/// data. Defaults to `false`.
pub emit_metadata: bool,
/// Should the source map be inlined in the emitted code file, or provided
/// as a separate file. Defaults to `true`.
pub inline_source_map: bool,
/// When transforming JSX, what value should be used for the JSX factory.
/// Defaults to `React.createElement`.
pub jsx_factory: String,
/// When transforming JSX, what value should be used for the JSX fragment
/// factory. Defaults to `React.Fragment`.
pub jsx_fragment_factory: String,
/// Should JSX be transformed or preserved. Defaults to `true`.
pub transform_jsx: bool,
}
impl Default for EmitOptions {
fn default() -> Self {
EmitOptions {
check_js: false,
emit_metadata: false,
inline_source_map: true,
jsx_factory: "React.createElement".into(),
jsx_fragment_factory: "React.Fragment".into(),
transform_jsx: true,
}
}
}
impl From<tsc_config::TsConfig> for EmitOptions {
fn from(config: tsc_config::TsConfig) -> Self {
let options: tsc_config::EmitConfigOptions =
serde_json::from_value(config.0).unwrap();
EmitOptions {
check_js: options.check_js,
emit_metadata: options.emit_decorator_metadata,
inline_source_map: options.inline_source_map,
jsx_factory: options.jsx_factory,
jsx_fragment_factory: options.jsx_fragment_factory,
transform_jsx: options.jsx == "react",
}
}
}
/// A logical structure to hold the value of a parsed module for further
/// processing.
#[derive(Clone)]
pub struct ParsedModule {
comments: SingleThreadedComments,
leading_comments: Vec<Comment>,
module: Module,
source_map: Rc<SourceMap>,
source_file: Rc<SourceFile>,
}
impl fmt::Debug for ParsedModule {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("ParsedModule")
.field("comments", &self.comments)
.field("leading_comments", &self.leading_comments)
.field("module", &self.module)
.finish()
}
}
impl ParsedModule {
/// Return a vector of dependencies for the module.
pub fn analyze_dependencies(&self) -> Vec<DependencyDescriptor> {
analyze_dependencies(&self.module, &self.source_map, &self.comments)
}
/// Get the module's leading comments, where triple slash directives might
/// be located.
pub fn get_leading_comments(&self) -> Vec<Comment> {
self.leading_comments.clone()
}
/// Get a location for a given span within the module.
pub fn get_location(&self, span: &Span) -> Location {
self.source_map.lookup_char_pos(span.lo).into()
}
/// Transform a TypeScript file into a JavaScript file, based on the supplied
/// options.
///
/// The result is a tuple of the code and optional source map as strings.
pub fn transpile(
self,
options: &EmitOptions,
) -> Result<(String, Option<String>), AnyError> {
let program = Program::Module(self.module);
let jsx_pass = react::react(
self.source_map.clone(),
Some(&self.comments),
react::Options {
pragma: options.jsx_factory.clone(),
pragma_frag: options.jsx_fragment_factory.clone(),
// this will use `Object.assign()` instead of the `_extends` helper
// when spreading props.
use_builtins: true,
..Default::default()
},
);
let mut passes = chain!(
Optional::new(jsx_pass, options.transform_jsx),
proposals::decorators::decorators(proposals::decorators::Config {
legacy: true,
emit_metadata: options.emit_metadata
}),
helpers::inject_helpers(),
typescript::strip(),
fixer(Some(&self.comments)),
hygiene(),
);
let program = swc_common::GLOBALS.set(&Globals::new(), || {
helpers::HELPERS.set(&helpers::Helpers::new(false), || {
program.fold_with(&mut passes)
})
});
let mut src_map_buf = vec![];
let mut buf = vec![];
{
let writer = Box::new(JsWriter::new(
self.source_map.clone(),
"\n",
&mut buf,
Some(&mut src_map_buf),
));
let config = swc_ecmascript::codegen::Config { minify: false };
let mut emitter = swc_ecmascript::codegen::Emitter {
cfg: config,
comments: Some(&self.comments),
cm: self.source_map.clone(),
wr: writer,
};
program.emit_with(&mut emitter)?;
}
let mut src = String::from_utf8(buf)?;
let mut map: Option<String> = None;
{
let mut buf = Vec::new();
self
.source_map
.build_source_map_from(&mut src_map_buf, None)
.to_writer(&mut buf)?;
if options.inline_source_map {
src.push_str("//# sourceMappingURL=data:application/json;base64,");
let encoded_map = base64::encode(buf);
src.push_str(&encoded_map);
} else {
map = Some(String::from_utf8(buf)?);
}
}
Ok((src, map))
}
}
pub fn parse_with_source_map(
specifier: &str,
source: &str,
media_type: &MediaType,
source_map: Rc<SourceMap>,
) -> Result<ParsedModule, AnyError> {
let source_file = source_map.new_source_file(
FileName::Custom(specifier.to_string()),
source.to_string(),
);
let error_buffer = ErrorBuffer::new();
let syntax = get_syntax(media_type);
let input = StringInput::from(&*source_file);
let comments = SingleThreadedComments::default();
let handler = Handler::with_emitter_and_flags(
Box::new(error_buffer.clone()),
HandlerFlags {
can_emit_warnings: true,
dont_buffer_diagnostics: true,
..HandlerFlags::default()
},
);
let lexer = Lexer::new(syntax, TARGET, input, Some(&comments));
let mut parser = swc_ecmascript::parser::Parser::new_from(lexer);
let sm = &source_map;
let module = parser.parse_module().map_err(move |err| {
let mut diagnostic = err.into_diagnostic(&handler);
diagnostic.emit();
DiagnosticBuffer::from_error_buffer(error_buffer, |span| {
sm.lookup_char_pos(span.lo)
})
})?;
let leading_comments =
comments.with_leading(module.span.lo, |comments| comments.to_vec());
Ok(ParsedModule {
leading_comments,
module,
source_map,
comments,
source_file,
})
}
/// For a given specifier, source, and media type, parse the source of the
/// module and return a representation which can be further processed.
///
/// # Arguments
///
/// - `specifier` - The module specifier for the module.
/// - `source` - The source code for the module.
/// - `media_type` - The media type for the module.
///
// NOTE(bartlomieju): `specifier` has `&str` type instead of
// `&ModuleSpecifier` because runtime compiler APIs don't
// require valid module specifiers
pub fn parse(
specifier: &str,
source: &str,
media_type: &MediaType,
) -> Result<ParsedModule, AnyError> {
let source_map = Rc::new(SourceMap::default());
parse_with_source_map(specifier, source, media_type, source_map)
}
pub enum TokenOrComment {
Token(Token),
Comment { kind: CommentKind, text: String },
}
pub struct LexedItem {
pub span: Span,
pub inner: TokenOrComment,
}
impl LexedItem {
pub fn span_as_range(&self) -> Range<usize> {
self.span.lo.0 as usize..self.span.hi.0 as usize
}
}
fn flatten_comments(
comments: SingleThreadedComments,
) -> impl Iterator<Item = Comment> {
let (leading, trailing) = comments.take_all();
let mut comments = (*leading).clone().into_inner();
comments.extend((*trailing).clone().into_inner());
comments.into_iter().flat_map(|el| el.1)
}
pub fn lex(
specifier: &str,
source: &str,
media_type: &MediaType,
) -> Vec<LexedItem> {
let source_map = SourceMap::default();
let source_file = source_map.new_source_file(
FileName::Custom(specifier.to_string()),
source.to_string(),
);
let comments = SingleThreadedComments::default();
let lexer = Lexer::new(
get_syntax(media_type),
TARGET,
StringInput::from(source_file.as_ref()),
Some(&comments),
);
let mut tokens: Vec<LexedItem> = lexer
.map(|token| LexedItem {
span: token.span,
inner: TokenOrComment::Token(token.token),
})
.collect();
tokens.extend(flatten_comments(comments).map(|comment| LexedItem {
span: comment.span,
inner: TokenOrComment::Comment {
kind: comment.kind,
text: comment.text,
},
}));
tokens.sort_by_key(|item| item.span.lo.0);
tokens
}
/// A low level function which transpiles a source module into an swc
/// SourceFile.
pub fn transpile_module(
filename: &str,
src: &str,
media_type: &MediaType,
emit_options: &EmitOptions,
globals: &Globals,
cm: Rc<SourceMap>,
) -> Result<(Rc<SourceFile>, Module), AnyError> {
let parsed_module =
parse_with_source_map(filename, src, media_type, cm.clone())?;
let jsx_pass = react::react(
cm,
Some(&parsed_module.comments),
react::Options {
pragma: emit_options.jsx_factory.clone(),
pragma_frag: emit_options.jsx_fragment_factory.clone(),
// this will use `Object.assign()` instead of the `_extends` helper
// when spreading props.
use_builtins: true,
..Default::default()
},
);
let mut passes = chain!(
Optional::new(jsx_pass, emit_options.transform_jsx),
proposals::decorators::decorators(proposals::decorators::Config {
legacy: true,
emit_metadata: emit_options.emit_metadata
}),
helpers::inject_helpers(),
typescript::strip(),
fixer(Some(&parsed_module.comments)),
);
let source_file = parsed_module.source_file.clone();
let module = parsed_module.module;
let module = swc_common::GLOBALS.set(globals, || {
helpers::HELPERS.set(&helpers::Helpers::new(false), || {
module.fold_with(&mut passes)
})
});
Ok((source_file, module))
}
pub struct BundleHook;
impl swc_bundler::Hook for BundleHook {
fn get_import_meta_props(
&self,
span: swc_common::Span,
module_record: &swc_bundler::ModuleRecord,
) -> Result<Vec<swc_ecmascript::ast::KeyValueProp>, AnyError> {
use swc_ecmascript::ast;
// we use custom file names, and swc "wraps" these in `<` and `>` so, we
// want to strip those back out.
let mut value = module_record.file_name.to_string();
value.pop();
value.remove(0);
Ok(vec![
ast::KeyValueProp {
key: ast::PropName::Ident(ast::Ident::new("url".into(), span)),
value: Box::new(ast::Expr::Lit(ast::Lit::Str(ast::Str {
span,
value: value.into(),
kind: ast::StrKind::Synthesized,
has_escape: false,
}))),
},
ast::KeyValueProp {
key: ast::PropName::Ident(ast::Ident::new("main".into(), span)),
value: Box::new(if module_record.is_entry {
ast::Expr::Member(ast::MemberExpr {
span,
obj: ast::ExprOrSuper::Expr(Box::new(ast::Expr::MetaProp(
ast::MetaPropExpr {
meta: ast::Ident::new("import".into(), span),
prop: ast::Ident::new("meta".into(), span),
},
))),
prop: Box::new(ast::Expr::Ident(ast::Ident::new(
"main".into(),
span,
))),
computed: false,
})
} else {
ast::Expr::Lit(ast::Lit::Bool(ast::Bool { span, value: false }))
}),
},
])
}
}
#[cfg(test)]
mod tests {
use super::*;
use swc_ecmascript::dep_graph::DependencyKind;
#[test]
fn test_parsed_module_analyze_dependencies() {
let specifier =
ModuleSpecifier::resolve_url_or_path("https://deno.land/x/mod.js")
.unwrap();
let source = r#"import * as bar from "./test.ts";
const foo = await import("./foo.ts");
"#;
let parsed_module =
parse(specifier.as_str(), source, &MediaType::JavaScript)
.expect("could not parse module");
let actual = parsed_module.analyze_dependencies();
assert_eq!(
actual,
vec![
DependencyDescriptor {
kind: DependencyKind::Import,
is_dynamic: false,
leading_comments: Vec::new(),
col: 0,
line: 1,
specifier: "./test.ts".into(),
specifier_col: 21,
specifier_line: 1,
},
DependencyDescriptor {
kind: DependencyKind::Import,
is_dynamic: true,
leading_comments: Vec::new(),
col: 22,
line: 2,
specifier: "./foo.ts".into(),
specifier_col: 29,
specifier_line: 2,
}
]
);
}
#[test]
fn test_transpile() {
let specifier =
ModuleSpecifier::resolve_url_or_path("https://deno.land/x/mod.ts")
.expect("could not resolve specifier");
let source = r#"
enum D {
A,
B,
C,
}
export class A {
private b: string;
protected c: number = 1;
e: "foo";
constructor (public d = D.A) {
const e = "foo" as const;
this.e = e;
}
}
"#;
let module = parse(specifier.as_str(), source, &MediaType::TypeScript)
.expect("could not parse module");
let (code, maybe_map) = module
.transpile(&EmitOptions::default())
.expect("could not strip types");
assert!(code.starts_with("var D;\n(function(D) {\n"));
assert!(
code.contains("\n//# sourceMappingURL=data:application/json;base64,")
);
assert!(maybe_map.is_none());
}
#[test]
fn test_transpile_tsx() {
let specifier =
ModuleSpecifier::resolve_url_or_path("https://deno.land/x/mod.ts")
.expect("could not resolve specifier");
let source = r#"
export class A {
render() {
return <div><span></span></div>
}
}
"#;
let module = parse(specifier.as_str(), source, &MediaType::TSX)
.expect("could not parse module");
let (code, _) = module
.transpile(&EmitOptions::default())
.expect("could not strip types");
assert!(code.contains("React.createElement(\"div\", null"));
}
#[test]
fn test_transpile_decorators() {
let specifier =
ModuleSpecifier::resolve_url_or_path("https://deno.land/x/mod.ts")
.expect("could not resolve specifier");
let source = r#"
function enumerable(value: boolean) {
return function (
_target: any,
_propertyKey: string,
descriptor: PropertyDescriptor,
) {
descriptor.enumerable = value;
};
}
export class A {
@enumerable(false)
a() {
Test.value;
}
}
"#;
let module = parse(specifier.as_str(), source, &MediaType::TypeScript)
.expect("could not parse module");
let (code, _) = module
.transpile(&EmitOptions::default())
.expect("could not strip types");
assert!(code.contains("_applyDecoratedDescriptor("));
}
}