Add support for inline source maps in input

Closes parcel-bundler#219

Author: devongovett

Cargo.lock

@@ -31,13 +31,12 @@ parcel_selectors = { version = "0.24.4", path = "./selectors" }
 itertools = "0.10.1"
 smallvec = { version = "1.7.0", features = ["union"] }
 bitflags = "1.3.2"
-parcel_sourcemap = "2.0.2"
+parcel_sourcemap = { version = "2.1.0", features = ["json"] }
 data-encoding = "2.3.2"
 lazy_static = "1.4.0"
 const-str = "0.3.1"
 # CLI deps
 clap = { version = "3.0.6", features = ["derive"], optional = true }
-serde_json = { version = "1.0.78", optional = true }
 pathdiff = { version = "0.2.1", optional = true }
 browserslist-rs = { version = "0.7.0", optional = true }
 rayon = "1.5.1"
@@ -51,11 +50,11 @@ indoc = "1.0.3"
 assert_cmd = "2.0"
 assert_fs = "1.0"
 predicates = "2.1"
-serde_json = "1.0.78"
+serde_json = "1"
 
 [features]
 default = ["grid"]
-cli = ["clap", "serde_json", "pathdiff", "browserslist-rs", "jemallocator"]
+cli = ["clap", "pathdiff", "browserslist-rs", "jemallocator"]
 grid = []
 serde = ["smallvec/serde", "cssparser/serde"]
 

Cargo.toml

@@ -11,10 +11,9 @@ crate-type = ["cdylib"]
 [dependencies]
 serde = { version = "1.0.123", features = ["derive"] }
 serde_bytes = "0.11.5"
-serde_json = "*"
 cssparser = "0.29.1"
 parcel_css = { path = "../" }
-parcel_sourcemap = "2.0.2"
+parcel_sourcemap = { version = "2.1.0", features = ["json"] }
 
 [target.'cfg(target_os = "macos")'.dependencies]
 jemallocator = { version = "0.3.2", features = ["disable_initial_exec_tls"] }

node/Cargo.toml

@@ -49,16 +49,6 @@ use napi::{CallContext, JsObject, JsUnknown};
 #[cfg(not(target_arch = "wasm32"))]
 use napi_derive::{js_function, module_exports};
 
-#[derive(Serialize)]
-#[serde(rename_all = "camelCase")]
-struct SourceMapJson<'a> {
-  version: u8,
-  mappings: String,
-  sources: &'a Vec<String>,
-  sources_content: &'a Vec<String>,
-  names: &'a Vec<String>,
-}
-
 #[derive(Serialize)]
 #[serde(rename_all = "camelCase")]
 struct TransformResult {
@@ -299,7 +289,7 @@ fn compile<'i>(code: &'i str, config: &Config) -> Result<TransformResult, Compil
   })?;
 
   let map = if let Some(mut source_map) = source_map {
-    Some(source_map_to_json(&mut source_map)?)
+    source_map.to_json(None).ok()
   } else {
     None
   };
@@ -363,7 +353,7 @@ fn compile_bundle<'i>(fs: &'i FileProvider, config: &BundleConfig) -> Result<Tra
   })?;
 
   let map = if let Some(source_map) = &mut source_map {
-    Some(source_map_to_json(source_map)?)
+    source_map.to_json(None).ok()
   } else {
     None
   };
@@ -377,22 +367,6 @@ fn compile_bundle<'i>(fs: &'i FileProvider, config: &BundleConfig) -> Result<Tra
   })
 }
 
-#[inline]
-fn source_map_to_json<'i>(source_map: &mut SourceMap) -> Result<Vec<u8>, CompileError<'i>> {
-  let mut vlq_output: Vec<u8> = Vec::new();
-  source_map.write_vlq(&mut vlq_output)?;
-
-  let sm = SourceMapJson {
-    version: 3,
-    mappings: unsafe { String::from_utf8_unchecked(vlq_output) },
-    sources: source_map.get_sources(),
-    sources_content: source_map.get_sources_content(),
-    names: source_map.get_names(),
-  };
-
-  Ok(serde_json::to_vec(&sm).unwrap())
-}
-
 #[derive(Serialize, Debug, Deserialize)]
 #[serde(rename_all = "camelCase")]
 struct AttrConfig {

node/src/lib.rs

@@ -19012,4 +19012,33 @@ mod tests {
     minify_test(".foo { z-index: 9999999 }", ".foo{z-index:9999999}");
     minify_test(".foo { z-index: -9999999 }", ".foo{z-index:-9999999}");
   }
+
+  #[test]
+  fn test_input_source_map() {
+    let source = r#".imported {
+      content: "yay, file support!";
+    }
+    
+    .selector {
+      margin: 1em;
+      background-color: #f60;
+    }
+    
+    .selector .nested {
+      margin: 0.5em;
+    }
+    
+    /*# sourceMappingURL=data:application/json;base64,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 */"#;
+
+    let mut stylesheet = StyleSheet::parse("test.css", &source, ParserOptions::default()).unwrap();
+    stylesheet.minify(MinifyOptions::default()).unwrap();
+    let mut sm = parcel_sourcemap::SourceMap::new("/");
+    stylesheet.to_css(PrinterOptions {
+      source_map: Some(&mut sm),
+      minify: true,
+      ..PrinterOptions::default()
+    }).unwrap();
+    let map = sm.to_json(None).unwrap();
+    assert_eq!(map, r#"{"version":3,"sourceRoot":null,"mappings":"AEAA,uCFGA,2CAAA","sources":["stdin","sass/_variables.scss","sass/_demo.scss"],"sourcesContent":["@import \"_variables\";\n@import \"_demo\";\n\n.selector {\n  margin: $size;\n  background-color: $brandColor;\n\n  .nested {\n    margin: $size / 2;\n  }\n}","$brandColor: #f60;\n$size: 1em;",".imported {\n  content: \"yay, file support!\";\n}"],"names":[]}"#);
+  }
 }

src/lib.rs

@@ -60,7 +60,7 @@ pub struct PseudoClasses<'a> {
 pub struct Printer<'a, 'b, 'c, W> {
   pub(crate) sources: Option<&'c Vec<String>>,
   dest: &'a mut W,
-  source_map: Option<&'a mut SourceMap>,
+  pub(crate) source_map: Option<&'a mut SourceMap>,
   pub(crate) loc: Location,
   indent: u8,
   line: u32,

src/printer.rs

@@ -15,6 +15,7 @@ use crate::rules::{CssRule, CssRuleList, MinifyContext};
 use crate::targets::Browsers;
 use crate::traits::ToCss;
 use cssparser::{Parser, ParserInput, RuleListParser};
+use parcel_sourcemap::SourceMap;
 use std::collections::{HashMap, HashSet};
 
 pub use crate::parser::ParserOptions;
@@ -65,6 +66,8 @@ pub struct StyleSheet<'i, 'o> {
   /// A list of file names for all source files included within the style sheet.
   /// Sources are referenced by index in the `loc` property of each rule.
   pub sources: Vec<String>,
+  /// The source map URL extracted from the original style sheet.
+  pub source_map_url: Option<String>,
   #[cfg_attr(feature = "serde", serde(skip))]
   /// The options the style sheet was originally parsed with.
   options: ParserOptions<'o>,
@@ -103,6 +106,7 @@ impl<'i, 'o> StyleSheet<'i, 'o> {
   pub fn new(sources: Vec<String>, rules: CssRuleList<'i>, options: ParserOptions<'o>) -> StyleSheet<'i, 'o> {
     StyleSheet {
       sources,
+      source_map_url: None,
       rules,
       options,
     }
@@ -128,11 +132,18 @@ impl<'i, 'o> StyleSheet<'i, 'o> {
 
     Ok(StyleSheet {
       sources: vec![filename],
+      source_map_url: parser.current_source_map_url().map(|s| s.to_owned()),
       rules: CssRuleList(rules),
       options,
     })
   }
 
+  /// Returns the inline source map associated with the style sheet.
+  pub fn source_map(&self) -> Option<SourceMap> {
+    let source_map_url = self.source_map_url.as_ref()?;
+    SourceMap::from_data_url("/", source_map_url).ok()
+  }
+
   /// Minify and transform the style sheet for the provided browser targets.
   pub fn minify(&mut self, options: MinifyOptions) -> Result<(), Error<MinifyErrorKind>> {
     let mut context = PropertyHandlerContext::new(options.targets, &options.unused_symbols);
@@ -206,6 +217,13 @@ impl<'i, 'o> StyleSheet<'i, 'o> {
     } else {
       self.rules.to_css(&mut printer)?;
       printer.newline()?;
+
+      if let Some(sm) = printer.source_map {
+        if let Some(mut input_sm) = self.source_map() {
+          let _ = sm.extends(&mut input_sm);
+        }
+      }
+
       Ok(ToCssResult {
         dependencies: printer.dependencies,
         code: dest,