return a parse error

Author: Swatinem

src/lib.rs

@@ -1,6 +1,7 @@
 #![doc = include_str!("../README.md")]
 #![warn(missing_docs)]
 
+use std::fmt::Display;
 use std::ops::Range;
 
 mod name_resolver;
@@ -13,6 +14,7 @@ pub use name_resolver::NameResolver;
 pub use scope_index::{ScopeIndex, ScopeIndexError, ScopeLookupResult};
 pub use scope_name::{NameComponent, ScopeName};
 pub use source::{SourceContext, SourceContextError, SourcePosition};
+use swc_common::Spanned;
 
 /// The Scopes extracted from a piece of JS Code.
 pub type Scopes = Vec<(Range<u32>, Option<ScopeName>)>;
@@ -53,6 +55,26 @@ pub type Scopes = Vec<(Range<u32>, Option<ScopeName>)>;
 /// assert_eq!(scopes, expected);
 /// ```
 #[tracing::instrument(level = "trace", skip_all)]
-pub fn extract_scope_names(src: &str) -> Scopes {
-    swc::parse_with_swc(src)
+pub fn extract_scope_names(src: &str) -> Result<Scopes, ParseError> {
+    swc::parse_with_swc(src).map_err(|e| ParseError { inner: e })
 }
+
+/// An error parsing the JS Source provided to [`extract_scope_names`].
+#[derive(Debug)]
+pub struct ParseError {
+    inner: swc::ParseError,
+}
+
+impl Display for ParseError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let span = self.inner.span();
+        f.write_fmt(format_args!(
+            "{}:{}:{}",
+            span.lo.0,
+            span.hi.0,
+            self.inner.kind().msg()
+        ))
+    }
+}
+
+impl std::error::Error for ParseError {}

src/swc.rs

@@ -8,22 +8,20 @@ use swc_ecma_visit::{AstNodePath, VisitAstPath, VisitWithPath};
 use crate::scope_name::{NameComponent, ScopeName};
 use crate::Scopes;
 
+pub(crate) use swc_ecma_parser::error::Error as ParseError;
+
 // TODO:
 // - getters / setters
 // - maybe even computed properties?
 
-pub fn parse_with_swc(src: &str) -> Scopes {
+pub fn parse_with_swc(src: &str) -> Result<Scopes, ParseError> {
     let syntax = tracing::trace_span!("parsing source").in_scope(|| {
         let input = StringInput::new(src, BytePos(0), BytePos(src.len() as u32));
 
         let mut parser = Parser::new(swc_ecma_parser::Syntax::default(), input, None);
 
         parser.parse_module()
-    });
-    let syntax = match syntax {
-        Ok(syntax) => syntax,
-        Err(_) => return vec![],
-    };
+    })?;
 
     // dbg!(&syntax);
 
@@ -32,7 +30,7 @@ pub fn parse_with_swc(src: &str) -> Scopes {
 
         syntax.visit_children_with_path(&mut collector, &mut Default::default());
 
-        collector.into_scopes()
+        Ok(collector.into_scopes())
     })
 }
 

tests/extract.rs

@@ -16,7 +16,7 @@ fn extracts_named_fn() {
             return function fn_expr() {};
         }
         "#;
-    let scopes = extract_scope_names(src);
+    let scopes = extract_scope_names(src).unwrap();
     let scopes = scope_strs(scopes);
 
     let expected = [
@@ -35,7 +35,7 @@ fn extracts_named_class() {
             }
         }
         "#;
-    let scopes = extract_scope_names(src);
+    let scopes = extract_scope_names(src).unwrap();
     let scopes = scope_strs(scopes);
 
     let expected = [
@@ -52,7 +52,7 @@ fn infer_from_decl() {
         let anon_class = class {};
         const arrow = () => {};
         "#;
-    let scopes = extract_scope_names(src);
+    let scopes = extract_scope_names(src).unwrap();
     let scopes = scope_strs(scopes);
 
     let expected = [
@@ -69,7 +69,7 @@ fn infer_from_assign() {
         assigned_fn = function () {};
         deep.assigned.klass = class {};
         "#;
-    let scopes = extract_scope_names(src);
+    let scopes = extract_scope_names(src).unwrap();
     let scopes = scope_strs(scopes);
 
     let expected = [
@@ -89,7 +89,7 @@ fn extract_obj_literal() {
             method_prop() {},
         };
         "#;
-    let scopes = extract_scope_names(src);
+    let scopes = extract_scope_names(src).unwrap();
     let scopes = scope_strs(scopes);
 
     let expected = [
@@ -110,7 +110,7 @@ fn extract_method_names() {
             #private_method() {}
         }
         "#;
-    let scopes = extract_scope_names(src);
+    let scopes = extract_scope_names(src).unwrap();
     let scopes = scope_strs(scopes);
 
     let expected = [

tests/integration.rs

@@ -30,7 +30,7 @@ fn resolves_scopes_simple() {
     let minified = std::fs::read_to_string("tests/fixtures/simple/minified.js").unwrap();
     let map = std::fs::read_to_string("tests/fixtures/simple/minified.js.map").unwrap();
 
-    let scopes = extract_scope_names(&minified);
+    let scopes = extract_scope_names(&minified).unwrap();
 
     let resolved_scopes = resolve_original_scopes(&minified, &map, scopes);
 
@@ -44,7 +44,7 @@ fn resolves_scopes_simple() {
 fn resolves_scope_names() {
     let src = std::fs::read_to_string("tests/fixtures/trace/sync.mjs").unwrap();
 
-    let scopes = extract_scope_names(&src);
+    let scopes = extract_scope_names(&src).unwrap();
     // dbg!(&scopes);
 
     let scopes: Vec<_> = scopes
@@ -173,7 +173,7 @@ fn resolves_token_from_names() {
     let minified = std::fs::read_to_string("tests/fixtures/preact.module.js").unwrap();
     let map = std::fs::read_to_string("tests/fixtures/preact.module.js.map").unwrap();
 
-    let scopes = extract_scope_names(&minified);
+    let scopes = extract_scope_names(&minified).unwrap();
 
     let resolved_scopes = resolve_original_scopes(&minified, &map, scopes);
 
@@ -189,7 +189,7 @@ fn parses_large_vendors() {
     let minified = std::fs::read_to_string("tests/fixtures/vendors/vendors.js").unwrap();
     let map = std::fs::read_to_string("tests/fixtures/vendors/vendors.js.map").unwrap();
 
-    let scopes = extract_scope_names(&minified);
+    let scopes = extract_scope_names(&minified).unwrap();
 
     let resolved_scopes = resolve_original_scopes(&minified, &map, scopes);