Handle input source map correctly (#830)

native/src/lib.rs

@@ -76,7 +76,7 @@ impl Task for TransformTask {
                 let program: Program =
                     serde_json::from_str(&s).expect("failed to deserialize Program");
                 // TODO: Source map
-                self.c.process_js(program, None, &self.options)
+                self.c.process_js(program, &self.options)
             }
 
             Input::File(ref path) => {
@@ -144,8 +144,7 @@ where
             if is_module.value() {
                 let program: Program =
                     serde_json::from_str(&s.value()).expect("failed to deserialize Program");
-                // TODO: Source map
-                c.process_js(program, None, &options)
+                c.process_js(program, &options)
             } else {
                 let fm = op(&c, s.value(), &options).expect("failed to create fm");
                 c.process_js_file(fm, &options)
@@ -246,16 +245,13 @@ impl Task for ParseTask {
 
     fn perform(&self) -> Result<Self::Output, Self::Error> {
         self.c.run(|| {
-            self.c
-                .parse_js(
+            self.c.parse_js(
                 self.fm.clone(),
                 self.options.target,
                 self.options.syntax,
                 self.options.is_module,
                 self.options.comments,
-                    &Default::default(),
             )
-                .map(|v| v.0)
         })
     }
 
@@ -281,16 +277,13 @@ impl Task for ParseFileTask {
                 .load_file(&self.path)
                 .context("failed to read module")?;
 
-            self.c
-                .parse_js(
+            self.c.parse_js(
                 fm,
                 self.options.target,
                 self.options.syntax,
                 self.options.is_module,
                 self.options.comments,
-                    &Default::default(),
             )
-                .map(|v| v.0)
         })
     }
 
@@ -348,9 +341,7 @@ fn parse_sync(mut cx: MethodContext<JsCompiler>) -> JsResult<JsValue> {
                 options.syntax,
                 options.is_module,
                 options.comments,
-                &Default::default(),
             )
-            .map(|v| v.0)
         };
 
         complete_parse(cx, program, &c)
@@ -381,9 +372,7 @@ fn parse_file_sync(mut cx: MethodContext<JsCompiler>) -> JsResult<JsValue> {
                 options.syntax,
                 options.is_module,
                 options.comments,
-                &Default::default(),
             )
-            .map(|v| v.0)
         };
 
         complete_parse(cx, program, &c)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@swc/core",
-  "version": "1.1.54",
+  "version": "1.1.55",
   "description": "Super-fast alternative for babel",
   "main": "./index.js",
   "author": "강동윤 <kdy1997.dev@gmail.com>",

src/config.rs

@@ -101,6 +101,7 @@ fn default_is_module() -> bool {
     true
 }
 
+/// Configuration related to source map generaged by swc.
 #[derive(Clone, Serialize, Deserialize)]
 #[serde(untagged)]
 pub enum SourceMapsConfig {
@@ -135,7 +136,7 @@ pub enum InputSourceMap {
 
 impl Default for InputSourceMap {
     fn default() -> Self {
-        InputSourceMap::Bool(true)
+        InputSourceMap::Bool(false)
     }
 }
 

src/lib.rs

@@ -5,15 +5,12 @@ pub use swc_atoms as atoms;
 pub use swc_common as common;
 pub use swc_ecmascript as ecmascript;
 
-mod builder;
-pub mod config;
-
 pub use crate::builder::PassBuilder;
 use crate::config::{
     BuiltConfig, Config, ConfigFile, InputSourceMap, JscTarget, Merge, Options, Rc, RootMode,
     SourceMapsConfig,
 };
-use anyhow::{Context, Error};
+use anyhow::{bail, Context, Error};
 use common::{
     comments::{Comment, Comments},
     errors::Handler,
@@ -41,6 +38,9 @@ use std::{
     sync::Arc,
 };
 
+mod builder;
+pub mod config;
+
 pub struct Compiler {
     /// swc uses rustc's span interning.
     ///
@@ -81,34 +81,29 @@ impl Compiler {
         })
     }
 
-    /// This method parses a javascript / typescript file
-    pub fn parse_js(
+    fn get_orig_src_map(
         &self,
-        fm: Arc<SourceFile>,
-        target: JscTarget,
-        syntax: Syntax,
-        is_module: bool,
-        parse_comments: bool,
-        input_source_map: &InputSourceMap,
-    ) -> Result<(Program, Option<sourcemap::SourceMap>), Error> {
-        self.run(|| {
-            let orig = (|| {
+        name: &FileName,
+        input_src_map: &InputSourceMap,
+    ) -> Result<Option<sourcemap::SourceMap>, Error> {
+        self.run(|| -> Result<_, Error> {
             // Load original source map
-                match input_source_map {
-                    InputSourceMap::Bool(false) => None,
+            match input_src_map {
+                InputSourceMap::Bool(false) => Ok(None),
                 InputSourceMap::Bool(true) => {
                     // Load original source map if possible
-                        match &fm.name {
+                    match &name {
                         FileName::Real(filename) => {
                             let path = format!("{}.map", filename.display());
-                                let file = File::open(&path).ok()?;
-                                Some(sourcemap::SourceMap::from_reader(file).with_context(|| {
-                                    format!("failed to read input source map from file at {}", path)
-                                }))
+                            let file = File::open(&path)
+                                .context("failed to open input source map file")?;
+                            Ok(Some(sourcemap::SourceMap::from_reader(file).with_context(
+                                || format!("failed to read input source map from file at {}", path),
+                            )?))
                         }
                         _ => {
                             log::error!("Failed to load source map for non-file input");
-                                return None;
+                            return Ok(None);
                         }
                     }
                 }
@@ -117,35 +112,44 @@ impl Compiler {
                         // Load inline source map by simple string
                         // operations
                         let s = "sourceMappingURL=data:application/json;base64,";
-                            let idx = s.rfind(s)?;
+                        let idx = s.rfind(s);
+                        let idx = match idx {
+                            None => bail!(
+                                "failed to parse inline source map: `sourceMappingURL` not found"
+                            ),
+                            Some(v) => v,
+                        };
                         let encoded = &s[idx + s.len()..];
 
                         let res = base64::decode(encoded.as_bytes())
-                                .context("failed to decode base64-encoded source map");
-                            let res = match res {
-                                Ok(v) => v,
-                                Err(err) => return Some(Err(err)),
-                            };
+                            .context("failed to decode base64-encoded source map")?;
 
-                            Some(sourcemap::SourceMap::from_slice(&res).context(
-                                "failed to read input source map from inlined base64 encoded \
-                                 string",
-                            ))
+                        Ok(Some(sourcemap::SourceMap::from_slice(&res).context(
+                            "failed to read input source map from inlined base64 encoded string",
+                        )?))
                     } else {
                         // Load source map passed by user
-                            Some(sourcemap::SourceMap::from_slice(s.as_bytes()).context(
+                        Ok(Some(
+                            sourcemap::SourceMap::from_slice(s.as_bytes()).context(
                                 "failed to read input source map from user-provided sourcemap",
+                            )?,
                         ))
                     }
                 }
             }
-            })();
-
-            let orig = match orig {
-                None => None,
-                Some(v) => Some(v?),
-            };
+        })
+    }
 
+    /// This method parses a javascript / typescript file
+    pub fn parse_js(
+        &self,
+        fm: Arc<SourceFile>,
+        target: JscTarget,
+        syntax: Syntax,
+        is_module: bool,
+        parse_comments: bool,
+    ) -> Result<Program, Error> {
+        self.run(|| {
             let session = ParseSess {
                 handler: &self.handler,
             };
@@ -179,7 +183,7 @@ impl Compiler {
                     .map(Program::Script)?
             };
 
-            Ok((program, orig))
+            Ok(program)
         })
     }
 
@@ -365,16 +369,16 @@ impl Compiler {
     ) -> Result<TransformOutput, Error> {
         self.run(|| -> Result<_, Error> {
             let config = self.run(|| self.config_for_file(opts, &fm.name))?;
-            let (program, src_map) = self.parse_js(
+            let orig = self.get_orig_src_map(&fm.name, &opts.input_source_map)?;
+            let program = self.parse_js(
                 fm.clone(),
                 config.target,
                 config.syntax,
                 config.is_module,
                 true,
-                &config.input_source_map,
             )?;
 
-            self.process_js_inner(program, src_map, config)
+            self.process_js_inner(program, orig.as_ref(), config)
         })
         .context("failed to process js file")
     }
@@ -382,19 +386,15 @@ impl Compiler {
     /// You can use custom pass with this method.
     ///
     /// There exists a [PassBuilder] to help building custom passes.
-    pub fn process_js(
-        &self,
-        program: Program,
-        src_map: Option<sourcemap::SourceMap>,
-        opts: &Options,
-    ) -> Result<TransformOutput, Error> {
+    pub fn process_js(&self, program: Program, opts: &Options) -> Result<TransformOutput, Error> {
         self.run(|| -> Result<_, Error> {
             let loc = self.cm.lookup_char_pos(program.span().lo());
             let fm = loc.file;
+            let orig = self.get_orig_src_map(&fm.name, &opts.input_source_map)?;
 
             let config = self.run(|| self.config_for_file(opts, &fm.name))?;
 
-            self.process_js_inner(program, src_map, config)
+            self.process_js_inner(program, orig.as_ref(), config)
         })
         .context("failed to process js module")
     }
@@ -402,7 +402,7 @@ impl Compiler {
     fn process_js_inner(
         &self,
         program: Program,
-        src_map: Option<sourcemap::SourceMap>,
+        orig: Option<&sourcemap::SourceMap>,
         config: BuiltConfig<impl Pass>,
     ) -> Result<TransformOutput, Error> {
         self.run(|| {
@@ -426,7 +426,7 @@ impl Compiler {
                 &program,
                 &self.comments,
                 config.source_maps,
-                src_map.as_ref(),
+                orig,
                 config.minify,
             )
         })

wasm/src/lib.rs

@@ -11,7 +11,7 @@ use swc::{
         errors::{EmitterWriter, Handler, HandlerFlags, SourceMapperDyn},
         FileName, FilePathMapping, SourceMap,
     },
-    config::{InputSourceMap, Options, ParseOptions, SourceMapsConfig},
+    config::{Options, ParseOptions, SourceMapsConfig},
     ecmascript::ast::Program,
     Compiler,
 };
@@ -28,28 +28,11 @@ pub fn parse_sync(s: &str, opts: JsValue) -> Result<JsValue, JsValue> {
     let (c, errors) = compiler();
 
     let fm = c.cm.new_source_file(FileName::Anon, s.into());
-    let (prog, src_map) = c
-        .parse_js(
-            fm,
-            opts.target,
-            opts.syntax,
-            opts.is_module,
-            opts.comments,
-            &InputSourceMap::Bool(false),
-        )
+    let program = c
+        .parse_js(fm, opts.target, opts.syntax, opts.is_module, opts.comments)
         .map_err(|err| format!("failed to parse: {}\n{}", err, errors))?;
 
-    let mut source_map = vec![];
-    if let Some(src_map) = src_map {
-        src_map
-            .to_writer(&mut source_map)
-            .map_err(|err| format!("failed to print source map file: {}", err))?;
-    }
-
-    Ok(
-        JsValue::from_serde(&(prog, &*String::from_utf8_lossy(&source_map)))
-            .map_err(|err| format!("failed to return value: {}", err))?,
-    )
+    Ok(JsValue::from_serde(&program).map_err(|err| format!("failed to return value: {}", err))?)
 }
 
 #[wasm_bindgen(js_name = "printSync")]