feat(compiler): add compat fixer

Author: ije

compiler/src/compat_fixer.rs

@@ -0,0 +1,48 @@
+// Copyright 2020-2021 postUI Lab. All rights reserved. MIT license.
+
+use crate::resolve::is_call_expr_by_name;
+
+use swc_common::DUMMY_SP;
+use swc_ecma_ast::*;
+use swc_ecma_utils::quote_ident;
+use swc_ecma_visit::{noop_fold_type, Fold};
+
+pub fn compat_fixer_fold() -> impl Fold {
+    CompatFixer {}
+}
+
+struct CompatFixer {}
+
+impl Fold for CompatFixer {
+    noop_fold_type!();
+
+    // - `require("regenerator-runtime")` -> `__ALEPH.require("regenerator-runtime")`
+    fn fold_call_expr(&mut self, call: CallExpr) -> CallExpr {
+        if is_call_expr_by_name(&call, "require") {
+            let ok = match call.args.first() {
+                Some(ExprOrSpread { expr, .. }) => match expr.as_ref() {
+                    Expr::Lit(lit) => match lit {
+                        Lit::Str(_) => true,
+                        _ => false,
+                    },
+                    _ => false,
+                },
+                _ => false,
+            };
+            if ok {
+                return CallExpr {
+                    span: DUMMY_SP,
+                    callee: ExprOrSuper::Expr(Box::new(Expr::Member(MemberExpr {
+                        span: DUMMY_SP,
+                        obj: ExprOrSuper::Expr(Box::new(Expr::Ident(quote_ident!("__ALEPH")))),
+                        prop: Box::new(Expr::Ident(quote_ident!("require"))),
+                        computed: false,
+                    }))),
+                    args: call.args,
+                    type_args: None,
+                };
+            }
+        }
+        call
+    }
+}

compiler/src/lib.rs

@@ -4,6 +4,7 @@
 extern crate lazy_static;
 
 mod aleph;
+mod compat_fixer;
 mod error;
 mod fast_refresh;
 mod import_map;

compiler/src/resolve.rs

@@ -686,7 +686,7 @@ pub fn is_remote_url(url: &str) -> bool {
   return url.starts_with("https://") || url.starts_with("http://");
 }
 
-fn is_call_expr_by_name(call: &CallExpr, name: &str) -> bool {
+pub fn is_call_expr_by_name(call: &CallExpr, name: &str) -> bool {
   let callee = match &call.callee {
     ExprOrSuper::Super(_) => return false,
     ExprOrSuper::Expr(callee) => callee.as_ref(),

compiler/src/swc.rs

@@ -1,6 +1,7 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 // Copyright 2020-2021 postUI Lab. All rights reserved. MIT license.
 
+use crate::compat_fixer::compat_fixer_fold;
 use crate::error::{DiagnosticBuffer, ErrorBuffer};
 use crate::fast_refresh::fast_refresh_fold;
 use crate::jsx::aleph_jsx_fold;
@@ -126,12 +127,12 @@ impl ParsedModule {
   ) -> Result<(String, Option<String>), anyhow::Error> {
     swc_common::GLOBALS.set(&Globals::new(), || {
       let specifier_is_remote = resolver.borrow_mut().specifier_is_remote;
-      let ts = match self.source_type {
+      let is_ts = match self.source_type {
         SourceType::TypeScript => true,
         SourceType::TSX => true,
         _ => false,
       };
-      let jsx = match self.source_type {
+      let is_jsx = match self.source_type {
         SourceType::JSX => true,
         SourceType::TSX => true,
         _ => false,
@@ -144,8 +145,8 @@ impl ParsedModule {
       let root_mark = Mark::fresh(Mark::root());
       let mut passes = chain!(
         aleph_resolve_fold(resolver.clone()),
-        Optional::new(aleph_jsx_fold, jsx),
-        Optional::new(aleph_jsx_builtin_resolve_fold, jsx),
+        Optional::new(aleph_jsx_fold, is_jsx),
+        Optional::new(aleph_jsx_builtin_resolve_fold, is_jsx),
         Optional::new(
           fast_refresh_fold(
             "$RefreshReg$",
@@ -167,21 +168,22 @@ impl ParsedModule {
               ..Default::default()
             },
           ),
-          jsx
+          is_jsx
         ),
         decorators::decorators(decorators::Config {
           legacy: true,
           emit_metadata: false
         }),
         Optional::new(es2020(), options.target < JscTarget::Es2020),
-        Optional::new(strip(), ts),
+        Optional::new(strip(), is_ts),
         Optional::new(es2018(), options.target < JscTarget::Es2018),
         Optional::new(es2017(), options.target < JscTarget::Es2017),
         Optional::new(es2016(), options.target < JscTarget::Es2016),
         Optional::new(
           es2015(root_mark, Default::default()),
           options.target < JscTarget::Es2015
         ),
+        Optional::new(compat_fixer_fold(), options.target < JscTarget::Es2015),
         Optional::new(
           helpers::inject_helpers(),
           options.target < JscTarget::Es2020