fix(es/codegen): Emit sourcemap of key-value properties correctly (#4166)

crates/swc/tests/fixture/issues-4xxx/issue-4120/1/output/index.map

@@ -1,5 +1,5 @@
 {
-  "mappings": "AAQA,cAAe,CARiF,AAQ/EA,CAAC,CARR,sFAAsF,AAQ/EA,CALsJ,AAKnJC,CAAC,CALX,mJAA6J,AAKnJA,CAAG,AAAC",
+  "mappings": "AAQA,cAAe,CAAEA,CAAC,CARR,sFAAsF,CAQ5EC,CAAC,CALX,mJAA6J,CAKhJ,AAAC",
   "names": [
     "a",
     "b"

crates/swc/tests/source_map.rs

@@ -11,7 +11,7 @@ use std::{
 
 use anyhow::{Context, Error};
 use swc::{
-    config::{Config, IsModule, Options, SourceMapsConfig},
+    config::{Config, IsModule, ModuleConfig, Options, SourceMapsConfig},
     Compiler,
 };
 use testing::{assert_eq, NormalizedOutput, StdErr, Tester};
@@ -227,3 +227,73 @@ fn extract_node_stack_trace(output: Output) -> NormalizedOutput {
 
     stacks.into()
 }
+
+#[test]
+fn issue_4112() {
+    Tester::new()
+        .print_errors(|cm, handler| {
+            let c = Compiler::new(cm.clone());
+            let fm = cm.new_source_file(
+                swc_common::FileName::Real("./browser.js".into()),
+                r#""use strict";
+
+            export { default as Selection } from "./selection";
+            
+            export { default as RichTextarea } from "./richTextarea";
+            "#
+                .to_string(),
+            );
+
+            let output1 = c
+                .process_js_file(
+                    fm,
+                    &handler,
+                    &Options {
+                        config: Config {
+                            module: Some(ModuleConfig::CommonJs(Default::default())),
+                            ..Default::default()
+                        },
+                        source_maps: Some(SourceMapsConfig::Bool(true)),
+                        ..Default::default()
+                    },
+                )
+                .expect("failed to process js file");
+            let fm2 = cm.new_source_file(
+                swc_common::FileName::Real("./preamble.js".into()),
+                r#""use strict";
+
+            import { React, window } from "easy";
+            
+            window.assign({
+              React
+            });
+            "#
+                .to_string(),
+            );
+            let output2 = c
+                .process_js_file(
+                    fm2,
+                    &handler,
+                    &Options {
+                        config: Config {
+                            module: Some(ModuleConfig::CommonJs(Default::default())),
+                            ..Default::default()
+                        },
+                        source_maps: Some(SourceMapsConfig::Bool(true)),
+                        ..Default::default()
+                    },
+                )
+                .expect("failed to process js file");
+            let source_count = sourcemap::SourceMap::from_slice(output2.map.unwrap().as_bytes())
+                .expect("failed to deserialize sourcemap")
+                .get_source_count();
+            if source_count == 1 {
+                return Ok(());
+            }
+            panic!(
+                "Validation failed, should has 1 source, but {}",
+                source_count
+            );
+        })
+        .unwrap()
+}

crates/swc_cli/src/commands/compile.rs

@@ -93,12 +93,12 @@ pub struct CompileOptions {
     /// `trace-{unix epoch time}.json` will be used by default.
     #[clap(group = "experimental_trace", long)]
     trace_out_file: Option<String>,
-    //Flags legacy @swc/cli supports, might need some thoughts if we need support same.
-    //log_watch_compilation: bool,
-    //copy_files: bool,
-    //include_dotfiles: bool,
-    //only: Option<String>,
-    //no_swcrc: bool,
+    /*Flags legacy @swc/cli supports, might need some thoughts if we need support same.
+     *log_watch_compilation: bool,
+     *copy_files: bool,
+     *include_dotfiles: bool,
+     *only: Option<String>,
+     *no_swcrc: bool, */
 }
 
 static COMPILER: Lazy<Arc<Compiler>> = Lazy::new(|| {

crates/swc_ecma_codegen/src/lib.rs

@@ -1826,15 +1826,25 @@ where
     #[emitter]
     fn emit_kv_prop(&mut self, node: &KeyValueProp) -> Result {
         self.emit_leading_comments_of_span(node.span(), false)?;
-
-        srcmap!(node, true);
-
+        let key_span = node.key.span();
+        let value_span = node.value.span();
+        if !key_span.is_dummy() {
+            self.wr.add_srcmap(key_span.lo)?;
+        }
         emit!(node.key);
+        if !key_span.is_dummy() && value_span.is_dummy() {
+            self.wr.add_srcmap(key_span.hi)?;
+        }
         punct!(":");
         formatting_space!();
+        if key_span.is_dummy() && !value_span.is_dummy() {
+            self.wr.add_srcmap(value_span.lo)?;
+        }
         emit!(node.value);
 
-        srcmap!(node, false);
+        if !value_span.is_dummy() {
+            self.wr.add_srcmap(value_span.hi)?;
+        }
     }
 
     #[emitter]

crates/swc_ecma_minifier/src/compress/pure/dead_code.rs

@@ -11,6 +11,7 @@ use crate::{
 
 /// Methods related to option `dead_code`.
 impl Pure<'_> {
+    ///
     ///  - Removes `L1: break L1`
     pub(super) fn drop_instant_break(&mut self, s: &mut Stmt) {
         if let Stmt::Labeled(ls) = s {

crates/swc_ecma_transforms_module/src/util.rs

@@ -517,7 +517,11 @@ impl Scope {
                     // import * as foo from 'foo';
                     Ok(obj)
                 } else {
-                    Ok(obj.make_member(Ident::new(prop, DUMMY_SP)))
+                    Ok(Expr::Member(MemberExpr {
+                        obj: Box::new(obj),
+                        span: orig_span,
+                        prop: Ident::new(prop, DUMMY_SP).into(),
+                    }))
                 }
             }
         }