chore(solc): improve io error for bad symlinks (#1594)

ethers-solc/src/error.rs

@@ -1,5 +1,8 @@
 use semver::Version;
-use std::{io, path::PathBuf};
+use std::{
+    io,
+    path::{Path, PathBuf},
+};
 use thiserror::Error;
 
 pub type Result<T> = std::result::Result<T, SolcError>;
@@ -27,6 +30,8 @@ pub enum SolcError {
     /// Failed to resolve a file
     #[error("Failed to resolve file: {0}.\n Check configured remappings.")]
     Resolve(SolcIoError),
+    #[error("File could not be resolved due to broken symlink: {0}.")]
+    ResolveBadSymlink(SolcIoError),
     #[cfg(feature = "svm-solc")]
     #[error(transparent)]
     SvmError(#[from] svm::SolcVmError),
@@ -83,6 +88,16 @@ impl SolcIoError {
     pub fn new(io: io::Error, path: impl Into<PathBuf>) -> Self {
         Self { io, path: path.into() }
     }
+
+    /// The path at which the error occurred
+    pub fn path(&self) -> &Path {
+        &self.path
+    }
+
+    /// The underlying `io::Error`
+    pub fn source(&self) -> &io::Error {
+        &self.io
+    }
 }
 
 impl From<SolcIoError> for io::Error {

ethers-solc/src/resolver/mod.rs

@@ -818,9 +818,15 @@ pub struct Node {
 
 impl Node {
     /// Reads the content of the file and returns a [Node] containing relevant information
-    pub fn read(file: impl AsRef<Path>) -> crate::Result<Self> {
+    pub fn read(file: impl AsRef<Path>) -> Result<Self> {
         let file = file.as_ref();
-        let source = Source::read(file).map_err(SolcError::Resolve)?;
+        let source = Source::read(file).map_err(|err| {
+            if !err.path().exists() && err.path().is_symlink() {
+                SolcError::ResolveBadSymlink(err)
+            } else {
+                SolcError::Resolve(err)
+            }
+        })?;
         let data = SolData::parse(source.as_ref(), file);
         Ok(Self { path: file.to_path_buf(), source, data })
     }