extern crate swc_common;
extern crate swc_ecma_ast;
use crate::test_utils::to_swc::Program;
/// JSX runtimes.
#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
pub enum JsxRuntime {
/// Automatic runtime.
///
/// With the automatic runtime, some module is expected to exist somewhere.
/// That modules is expected to expose a certain API.
/// The compiler adds an import of that module and compiles JSX away to
/// function calls that use that API.
#[default]
Automatic,
/// Classic runtime.
///
/// With the classic runtime, you define two values yourself in each file,
/// which are expected to work a certain way.
/// The compiler compiles JSX away to function calls using those two values.
Classic,
}
/// Configuration.
#[derive(Debug, PartialEq, Eq)]
pub struct Options {
/// Pragma for JSX (used in classic runtime).
///
/// Default: `React.createElement`.
pub pragma: Option<String>,
/// Pragma for JSX fragments (used in classic runtime).
///
/// Default: `React.Fragment`.
pub pragma_frag: Option<String>,
/// Where to import the identifier of `pragma` from (used in classic runtime).
///
/// Default: `react`.
pub pragma_import_source: Option<String>,
/// Place to import automatic JSX runtimes from (used in automatic runtime).
///
/// Default: `react`.
pub jsx_import_source: Option<String>,
/// JSX runtime to use.
///
/// Default: `automatic`.
pub jsx_runtime: Option<JsxRuntime>,
}
impl Default for Options {
/// Use the automatic JSX runtime with React.
fn default() -> Self {
Self {
pragma: None,
pragma_frag: None,
pragma_import_source: None,
jsx_import_source: None,
jsx_runtime: Some(JsxRuntime::default()),
}
}
}
#[allow(dead_code)]
pub fn to_document(mut program: Program, options: &Options) -> Result<Program, String> {
// New body children.
let mut replacements = vec![];
// Inject JSX configuration comment.
if let Some(runtime) = &options.jsx_runtime {
let mut pragmas = vec![];
let react = &"react".into();
let create_element = &"React.createElement".into();
let fragment = &"React.Fragment".into();
if *runtime == JsxRuntime::Automatic {
pragmas.push("@jsxRuntime automatic".into());
pragmas.push(format!(
"@jsxImportSource {}",
if let Some(jsx_import_source) = &options.jsx_import_source {
jsx_import_source
} else {
react
}
));
} else {
pragmas.push("@jsxRuntime classic".into());
pragmas.push(format!(
"@jsx {}",
if let Some(pragma) = &options.pragma {
pragma
} else {
create_element
}
));
pragmas.push(format!(
"@jsxFrag {}",
if let Some(pragma_frag) = &options.pragma_frag {
pragma_frag
} else {
fragment
}
));
}
if !pragmas.is_empty() {
program.comments.insert(
0,
swc_common::comments::Comment {
kind: swc_common::comments::CommentKind::Block,
text: pragmas.join(" ").into(),
span: swc_common::DUMMY_SP,
},
);
}
}
// Inject an import in the classic runtime for the pragma (and presumably,
// fragment).
if options.jsx_runtime == Some(JsxRuntime::Classic) {
let pragma = if let Some(pragma) = &options.pragma {
pragma
} else {
"React"
};
let sym = pragma.split('.').next().expect("first item always exists");
replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(
swc_ecma_ast::ModuleDecl::Import(swc_ecma_ast::ImportDecl {
specifiers: vec![swc_ecma_ast::ImportSpecifier::Named(
swc_ecma_ast::ImportNamedSpecifier {
local: swc_ecma_ast::Ident {
sym: sym.into(),
optional: false,
span: swc_common::DUMMY_SP,
},
imported: None,
span: swc_common::DUMMY_SP,
is_type_only: false,
},
)],
src: Box::new(swc_ecma_ast::Str {
value: (if let Some(source) = &options.pragma_import_source {
source.clone()
} else {
"react".into()
})
.into(),
span: swc_common::DUMMY_SP,
raw: None,
}),
type_only: false,
asserts: None,
span: swc_common::DUMMY_SP,
}),
));
}
// Find the `export default`, the JSX expression, and leave the rest as it
// is.
let mut input = program.module.body.split_off(0);
input.reverse();
// To do: place position in this.
let mut layout = false;
let content = true;
while let Some(module_item) = input.pop() {
match module_item {
// ```js
// export default props => <>{props.children}</>
// ```
//
// Treat it as an inline layout declaration.
//
// In estree, the below two are the same node (`ExportDefault`).
swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportDefaultDecl(
decl,
)) => {
// To do: use positional info.
if layout {
return Err("Cannot specify multiple layouts".into());
}
// To do: set positional info.
layout = true;
replacements.push(create_layout_decl(match decl.decl {
swc_ecma_ast::DefaultDecl::Class(cls) => swc_ecma_ast::Expr::Class(cls),
swc_ecma_ast::DefaultDecl::Fn(func) => swc_ecma_ast::Expr::Fn(func),
swc_ecma_ast::DefaultDecl::TsInterfaceDecl(_) => {
// To do: improved error? Not sure what a real example of this is?
unreachable!("Cannot use TypeScript interface declarations as default export in MDX")
},
}));
}
swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportDefaultExpr(
expr,
)) => {
// To do: use positional info.
if layout {
return Err("Cannot specify multiple layouts".into());
}
// To do: set positional info.
layout = true;
replacements.push(create_layout_decl(*expr.expr));
}
// ```js
// export {a, b as c} from 'd'
// export {a, b as c}
// ```
swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportNamed(mut named_export)) => {
// SWC is currently crashing when generating code, w/o source
// map, if an actual location is set on this node.
named_export.span = swc_common::DUMMY_SP;
let mut index = 0;
let mut id = None;
while index < named_export.specifiers.len() {
let mut take = false;
// Note: the `swc_ecma_ast::ExportSpecifier::Default`
// branch of this looks interesting, but as far as I
// understand it *is not* valid ES.
// `export a from 'b'` is a syntax error, even in SWC.
if let swc_ecma_ast::ExportSpecifier::Named(named) = &named_export.specifiers[index] {
if let Some(swc_ecma_ast::ModuleExportName::Ident(ident)) = &named.exported {
if ident.sym.as_ref() == "default" {
// For some reason the AST supports strings
// instead of identifiers.
// Looks like some TC39 proposal. Ignore for now
// and only do things if this is an ID.
if let swc_ecma_ast::ModuleExportName::Ident(ident) = &named.orig {
// To do: use positional info.
if layout {
return Err("Cannot specify multiple layouts".into());
}
// To do: set positional info.
layout = true;
take = true;
id = Some(ident.clone());
}
}
}
}
if take {
named_export.specifiers.remove(index);
} else {
index += 1;
}
}
if let Some(id) = id {
let source = named_export.src.clone();
// If there was just a default export, we can drop the original node.
if !named_export.specifiers.is_empty() {
// Pass through.
replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportNamed(named_export)));
}
// It’s an `export {x} from 'y'`, so generate an import.
if let Some(source) = source {
replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::Import(swc_ecma_ast::ImportDecl {
specifiers: vec![swc_ecma_ast::ImportSpecifier::Named(
swc_ecma_ast::ImportNamedSpecifier {
local: swc_ecma_ast::Ident {
sym: "MDXLayout".into(),
optional: false,
span: swc_common::DUMMY_SP,
},
imported: Some(swc_ecma_ast::ModuleExportName::Ident( id)),
span: swc_common::DUMMY_SP,
is_type_only: false,
},
)],
src: source,
type_only: false,
asserts: None,
span: swc_common::DUMMY_SP,
})))
}
// It’s an `export {x}`, so generate a variable declaration.
else {
replacements.push(create_layout_decl(swc_ecma_ast::Expr::Ident(id)));
}
} else {
// Pass through.
replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportNamed(named_export)));
}
}
swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::Import(_))
| swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportDecl(_))
| swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::ExportAll(_))
// To do: handle TS things?
| swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::TsImportEquals(_))
| swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::TsExportAssignment(
_,
))
| swc_ecma_ast::ModuleItem::ModuleDecl(swc_ecma_ast::ModuleDecl::TsNamespaceExport(
_,
)) => {
// Pass through.
replacements.push(module_item);
}
swc_ecma_ast::ModuleItem::Stmt(swc_ecma_ast::Stmt::Expr(expr_stmt)) => {
match *expr_stmt.expr {
swc_ecma_ast::Expr::JSXElement(elem) => {
replacements.append(&mut create_mdx_content(
Some(swc_ecma_ast::Expr::JSXElement(elem)),
layout,
));
}
swc_ecma_ast::Expr::JSXFragment(mut frag) => {
// Unwrap if possible.
if frag.children.len() == 1 {
let item = frag.children.pop().unwrap();
if let swc_ecma_ast::JSXElementChild::JSXElement(elem) = item {
replacements.append(&mut create_mdx_content(
Some(swc_ecma_ast::Expr::JSXElement(elem)),
layout,
));
continue;
}
frag.children.push(item)
}
replacements.append(&mut create_mdx_content(
Some(swc_ecma_ast::Expr::JSXFragment(frag)),
layout,
));
}
_ => {
// Pass through.
replacements.push(swc_ecma_ast::ModuleItem::Stmt(
swc_ecma_ast::Stmt::Expr(expr_stmt),
));
}
}
}
swc_ecma_ast::ModuleItem::Stmt(stmt) => {
replacements.push(swc_ecma_ast::ModuleItem::Stmt(stmt));
}
}
}
// Generate an empty component.
if !content {
replacements.append(&mut create_mdx_content(None, layout));
}
// ```jsx
// export default MDXContent
// ```
replacements.push(swc_ecma_ast::ModuleItem::ModuleDecl(
swc_ecma_ast::ModuleDecl::ExportDefaultExpr(swc_ecma_ast::ExportDefaultExpr {
expr: Box::new(swc_ecma_ast::Expr::Ident(swc_ecma_ast::Ident {
sym: "MDXContent".into(),
optional: false,
span: swc_common::DUMMY_SP,
})),
span: swc_common::DUMMY_SP,
}),
));
program.module.body = replacements;
Ok(program)
}
/// Create a content component.
fn create_mdx_content(
expr: Option<swc_ecma_ast::Expr>,
has_internal_layout: bool,
) -> Vec<swc_ecma_ast::ModuleItem> {
// ```jsx
// <MDXLayout {...props}>xxx</MDXLayout>
// ```
let mut result = swc_ecma_ast::Expr::JSXElement(Box::new(swc_ecma_ast::JSXElement {
opening: swc_ecma_ast::JSXOpeningElement {
name: swc_ecma_ast::JSXElementName::Ident(swc_ecma_ast::Ident {
sym: "MDXLayout".into(),
optional: false,
span: swc_common::DUMMY_SP,
}),
attrs: vec![swc_ecma_ast::JSXAttrOrSpread::SpreadElement(
swc_ecma_ast::SpreadElement {
dot3_token: swc_common::DUMMY_SP,
expr: Box::new(swc_ecma_ast::Expr::Ident(swc_ecma_ast::Ident {
sym: "props".into(),
optional: false,
span: swc_common::DUMMY_SP,
})),
},
)],
self_closing: false,
type_args: None,
span: swc_common::DUMMY_SP,
},
closing: Some(swc_ecma_ast::JSXClosingElement {
name: swc_ecma_ast::JSXElementName::Ident(swc_ecma_ast::Ident {
sym: "MDXLayout".into(),
optional: false,
span: swc_common::DUMMY_SP,
}),
span: swc_common::DUMMY_SP,
}),
// ```jsx
// <_createMdxContent {...props} />
// ```
children: vec![swc_ecma_ast::JSXElementChild::JSXElement(Box::new(
swc_ecma_ast::JSXElement {
opening: swc_ecma_ast::JSXOpeningElement {
name: swc_ecma_ast::JSXElementName::Ident(swc_ecma_ast::Ident {
sym: "_createMdxContent".into(),
optional: false,
span: swc_common::DUMMY_SP,
}),
attrs: vec![swc_ecma_ast::JSXAttrOrSpread::SpreadElement(
swc_ecma_ast::SpreadElement {
dot3_token: swc_common::DUMMY_SP,
expr: Box::new(swc_ecma_ast::Expr::Ident(swc_ecma_ast::Ident {
sym: "props".into(),
optional: false,
span: swc_common::DUMMY_SP,
})),
},
)],
self_closing: true,
type_args: None,
span: swc_common::DUMMY_SP,
},
closing: None,
children: vec![],
span: swc_common::DUMMY_SP,
},
))],
span: swc_common::DUMMY_SP,
}));
if !has_internal_layout {
// ```jsx
// MDXLayout ? <MDXLayout>xxx</MDXLayout> : _createMdxContent(props)
// ```
result = swc_ecma_ast::Expr::Cond(swc_ecma_ast::CondExpr {
test: Box::new(swc_ecma_ast::Expr::Ident(swc_ecma_ast::Ident {
sym: "MDXLayout".into(),
optional: false,
span: swc_common::DUMMY_SP,
})),
cons: Box::new(result),
alt: Box::new(swc_ecma_ast::Expr::Call(swc_ecma_ast::CallExpr {
callee: swc_ecma_ast::Callee::Expr(Box::new(swc_ecma_ast::Expr::Ident(
swc_ecma_ast::Ident {
sym: "_createMdxContent".into(),
optional: false,
span: swc_common::DUMMY_SP,
},
))),
args: vec![swc_ecma_ast::ExprOrSpread {
spread: None,
expr: Box::new(swc_ecma_ast::Expr::Ident(swc_ecma_ast::Ident {
sym: "props".into(),
optional: false,
span: swc_common::DUMMY_SP,
})),
}],
type_args: None,
span: swc_common::DUMMY_SP,
})),
span: swc_common::DUMMY_SP,
});
}
// ```jsx
// function _createMdxContent(props) {
// return xxx
// }
// ```
let create_mdx_content = swc_ecma_ast::ModuleItem::Stmt(swc_ecma_ast::Stmt::Decl(
swc_ecma_ast::Decl::Fn(swc_ecma_ast::FnDecl {
ident: swc_ecma_ast::Ident {
sym: "_createMdxContent".into(),
optional: false,
span: swc_common::DUMMY_SP,
},
declare: false,
function: Box::new(swc_ecma_ast::Function {
params: vec![swc_ecma_ast::Param {
pat: swc_ecma_ast::Pat::Ident(swc_ecma_ast::BindingIdent {
id: swc_ecma_ast::Ident {
sym: "props".into(),
optional: false,
span: swc_common::DUMMY_SP,
},
type_ann: None,
}),
decorators: vec![],
span: swc_common::DUMMY_SP,
}],
decorators: vec![],
body: Some(swc_ecma_ast::BlockStmt {
stmts: vec![swc_ecma_ast::Stmt::Return(swc_ecma_ast::ReturnStmt {
arg: Some(Box::new(expr.unwrap_or({
swc_ecma_ast::Expr::Lit(swc_ecma_ast::Lit::Null(swc_ecma_ast::Null {
span: swc_common::DUMMY_SP,
}))
}))),
span: swc_common::DUMMY_SP,
})],
span: swc_common::DUMMY_SP,
}),
is_generator: false,
is_async: false,
type_params: None,
return_type: None,
span: swc_common::DUMMY_SP,
}),
}),
));
// ```jsx
// function MDXContent(props = {}) {
// return <MDXLayout>xxx</MDXLayout>
// }
// ```
let mdx_content = swc_ecma_ast::ModuleItem::Stmt(swc_ecma_ast::Stmt::Decl(
swc_ecma_ast::Decl::Fn(swc_ecma_ast::FnDecl {
ident: swc_ecma_ast::Ident {
sym: "MDXContent".into(),
optional: false,
span: swc_common::DUMMY_SP,
},
declare: false,
function: Box::new(swc_ecma_ast::Function {
params: vec![swc_ecma_ast::Param {
pat: swc_ecma_ast::Pat::Assign(swc_ecma_ast::AssignPat {
left: Box::new(swc_ecma_ast::Pat::Ident(swc_ecma_ast::BindingIdent {
id: swc_ecma_ast::Ident {
sym: "props".into(),
optional: false,
span: swc_common::DUMMY_SP,
},
type_ann: None,
})),
right: Box::new(swc_ecma_ast::Expr::Object(swc_ecma_ast::ObjectLit {
props: vec![],
span: swc_common::DUMMY_SP,
})),
span: swc_common::DUMMY_SP,
type_ann: None,
}),
decorators: vec![],
span: swc_common::DUMMY_SP,
}],
decorators: vec![],
body: Some(swc_ecma_ast::BlockStmt {
stmts: vec![swc_ecma_ast::Stmt::Return(swc_ecma_ast::ReturnStmt {
arg: Some(Box::new(result)),
span: swc_common::DUMMY_SP,
})],
span: swc_common::DUMMY_SP,
}),
is_generator: false,
is_async: false,
type_params: None,
return_type: None,
span: swc_common::DUMMY_SP,
}),
}),
));
vec![create_mdx_content, mdx_content]
}
/// Create a layout, inside the document.
fn create_layout_decl(expr: swc_ecma_ast::Expr) -> swc_ecma_ast::ModuleItem {
// ```jsx
// const MDXLayout = xxx
// ```
swc_ecma_ast::ModuleItem::Stmt(swc_ecma_ast::Stmt::Decl(swc_ecma_ast::Decl::Var(Box::new(
swc_ecma_ast::VarDecl {
kind: swc_ecma_ast::VarDeclKind::Const,
declare: false,
decls: vec![swc_ecma_ast::VarDeclarator {
name: swc_ecma_ast::Pat::Ident(swc_ecma_ast::BindingIdent {
id: swc_ecma_ast::Ident {
sym: "MDXLayout".into(),
optional: false,
span: swc_common::DUMMY_SP,
},
type_ann: None,
}),
init: Some(Box::new(expr)),
span: swc_common::DUMMY_SP,
definite: false,
}],
span: swc_common::DUMMY_SP,
},
))))
}
