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denoland-deno/cli/swc_util.rs
2020-08-19 19:13:43 +02:00

303 lines
7.8 KiB
Rust

// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
use crate::msg::MediaType;
use deno_core::ErrBox;
use serde::Serialize;
use std::error::Error;
use std::fmt;
use std::rc::Rc;
use std::sync::Arc;
use std::sync::RwLock;
use swc_common::chain;
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::SourceMap;
use swc_common::Span;
use swc_ecmascript::ast::Program;
use swc_ecmascript::codegen::text_writer::JsWriter;
use swc_ecmascript::codegen::Node;
use swc_ecmascript::parser::lexer::Lexer;
use swc_ecmascript::parser::EsConfig;
use swc_ecmascript::parser::JscTarget;
use swc_ecmascript::parser::Parser;
use swc_ecmascript::parser::StringInput;
use swc_ecmascript::parser::Syntax;
use swc_ecmascript::parser::TsConfig;
use swc_ecmascript::transforms::fixer;
use swc_ecmascript::transforms::typescript;
use swc_ecmascript::visit::FoldWith;
#[derive(Debug, Serialize, Clone, 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,
}
}
}
struct DummyHandler;
impl swc_ecmascript::codegen::Handlers for DummyHandler {}
fn get_default_es_config() -> EsConfig {
let mut config = EsConfig::default();
config.num_sep = true;
config.class_private_props = true;
config.class_private_methods = true;
config.class_props = true;
config.export_default_from = true;
config.export_namespace_from = true;
config.dynamic_import = true;
config.nullish_coalescing = true;
config.optional_chaining = true;
config.import_meta = true;
config.top_level_await = true;
config
}
fn get_default_ts_config() -> TsConfig {
let mut ts_config = TsConfig::default();
ts_config.dynamic_import = true;
ts_config.decorators = true;
ts_config
}
pub fn get_syntax_for_media_type(media_type: MediaType) -> Syntax {
match media_type {
MediaType::JavaScript => Syntax::Es(get_default_es_config()),
MediaType::JSX => {
let mut config = get_default_es_config();
config.jsx = true;
Syntax::Es(config)
}
MediaType::TypeScript => Syntax::Typescript(get_default_ts_config()),
MediaType::TSX => {
let mut config = get_default_ts_config();
config.tsx = true;
Syntax::Typescript(config)
}
_ => Syntax::Es(get_default_es_config()),
}
}
#[derive(Clone, Debug)]
pub struct SwcDiagnosticBuffer {
pub diagnostics: Vec<String>,
}
impl Error for SwcDiagnosticBuffer {}
impl fmt::Display for SwcDiagnosticBuffer {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let msg = self.diagnostics.join(",");
f.pad(&msg)
}
}
impl SwcDiagnosticBuffer {
pub fn from_swc_error(
error_buffer: SwcErrorBuffer,
parser: &AstParser,
) -> Self {
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 location = parser.get_span_location(span);
let filename = match &location.file.name {
FileName::Custom(n) => n,
_ => unreachable!(),
};
msg = format!(
"{} at {}:{}:{}",
msg, filename, location.line, location.col_display
);
}
msg
})
.collect::<Vec<String>>();
Self { diagnostics }
}
}
#[derive(Clone)]
pub struct SwcErrorBuffer(Arc<RwLock<Vec<Diagnostic>>>);
impl SwcErrorBuffer {
pub fn default() -> Self {
Self(Arc::new(RwLock::new(vec![])))
}
}
impl Emitter for SwcErrorBuffer {
fn emit(&mut self, db: &DiagnosticBuilder) {
self.0.write().unwrap().push((**db).clone());
}
}
/// Low-level utility structure with common AST parsing functions.
///
/// Allows to build more complicated parser by providing a callback
/// to `parse_module`.
pub struct AstParser {
pub buffered_error: SwcErrorBuffer,
pub source_map: Rc<SourceMap>,
pub handler: Handler,
pub comments: SingleThreadedComments,
pub globals: Globals,
}
impl AstParser {
pub fn default() -> Self {
let buffered_error = SwcErrorBuffer::default();
let handler = Handler::with_emitter_and_flags(
Box::new(buffered_error.clone()),
HandlerFlags {
dont_buffer_diagnostics: true,
can_emit_warnings: true,
..Default::default()
},
);
AstParser {
buffered_error,
source_map: Rc::new(SourceMap::default()),
handler,
comments: SingleThreadedComments::default(),
globals: Globals::new(),
}
}
pub fn parse_module(
&self,
file_name: &str,
media_type: MediaType,
source_code: &str,
) -> Result<swc_ecmascript::ast::Module, SwcDiagnosticBuffer> {
let swc_source_file = self.source_map.new_source_file(
FileName::Custom(file_name.to_string()),
source_code.to_string(),
);
let buffered_err = self.buffered_error.clone();
let syntax = get_syntax_for_media_type(media_type);
let lexer = Lexer::new(
syntax,
JscTarget::Es2019,
StringInput::from(&*swc_source_file),
Some(&self.comments),
);
let mut parser = Parser::new_from(lexer);
parser.parse_module().map_err(move |err| {
let mut diagnostic = err.into_diagnostic(&self.handler);
diagnostic.emit();
SwcDiagnosticBuffer::from_swc_error(buffered_err, self)
})
}
pub fn strip_types(
&self,
file_name: &str,
media_type: MediaType,
source_code: &str,
) -> Result<String, ErrBox> {
let parse_result = self.parse_module(file_name, media_type, source_code);
let module = parse_result?;
let program = Program::Module(module);
let mut compiler_pass =
chain!(typescript::strip(), fixer(Some(&self.comments)));
let program = program.fold_with(&mut compiler_pass);
let mut src_map_buf = vec![];
let mut buf = vec![];
{
let handlers = Box::new(DummyHandler);
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,
handlers,
};
program.emit_with(&mut emitter)?;
}
let mut src = String::from_utf8(buf).map_err(ErrBox::from)?;
{
let mut buf = vec![];
self
.source_map
.build_source_map_from(&mut src_map_buf, None)
.to_writer(&mut buf)?;
let map = String::from_utf8(buf)?;
src.push_str("//# sourceMappingURL=data:application/json;base64,");
let encoded_map = base64::encode(map.as_bytes());
src.push_str(&encoded_map);
}
Ok(src)
}
pub fn get_span_location(&self, span: Span) -> swc_common::Loc {
self.source_map.lookup_char_pos(span.lo())
}
pub fn get_span_comments(
&self,
span: Span,
) -> Vec<swc_common::comments::Comment> {
self
.comments
.with_leading(span.lo(), |comments| comments.to_vec())
}
}
#[test]
fn test_strip_types() {
let ast_parser = AstParser::default();
let result = ast_parser
.strip_types("test.ts", MediaType::TypeScript, "const a: number = 10;")
.unwrap();
assert!(result.starts_with(
"const a = 10;\n//# sourceMappingURL=data:application/json;base64,"
));
}