fix: disallow flattening invalid files

Author: DaniPopes

crates/compilers/src/config.rs

@@ -135,6 +135,7 @@ impl ProjectPathsConfig<SolcLanguage> {
                 SolcError::msg(format!("cannot resolve file at {}", path.display()))
             })?;
             let node = graph.node(node_id);
+            node.data.parse_result()?;
             let content = node.content();
 
             // Firstly we strip all licesnses, verson pragmas

crates/compilers/src/resolver/parse.rs

@@ -20,9 +20,15 @@ pub struct SolData {
     pub libraries: Vec<SolLibrary>,
     pub contract_names: Vec<String>,
     pub is_yul: bool,
+    pub parse_result: Result<(), String>,
 }
 
 impl SolData {
+    /// Returns the result of parsing the file.
+    pub fn parse_result(&self) -> crate::Result<()> {
+        self.parse_result.clone().map_err(crate::SolcError::ParseError)
+    }
+
     #[allow(dead_code)]
     pub fn fmt_version<W: std::fmt::Write>(
         &self,
@@ -45,6 +51,7 @@ impl SolData {
         let mut imports = Vec::<Spanned<SolImport>>::new();
         let mut libraries = Vec::new();
         let mut contract_names = Vec::new();
+        let mut parse_error = Ok(());
 
         let sess = solar_parse::interface::Session::builder()
             .with_buffer_emitter(Default::default())
@@ -110,7 +117,9 @@ impl SolData {
             }
         });
         if let Err(e) = sess.emitted_diagnostics().unwrap() {
+            let e = e.to_string();
             trace!("failed parsing {file:?}: {e}");
+            parse_error = Err(e);
         }
         let license = content.lines().next().and_then(|line| {
             utils::capture_outer_and_inner(
@@ -132,6 +141,7 @@ impl SolData {
             libraries,
             contract_names,
             is_yul,
+            parse_result: parse_error,
         }
     }
 

crates/compilers/tests/project.rs

@@ -711,7 +711,7 @@ contract A { }
 }
 
 #[test]
-fn can_flatten_on_failure() {
+fn cannot_flatten_on_failure() {
     let project = TempProject::<MultiCompiler>::dapptools().unwrap();
 
     project
@@ -742,26 +742,8 @@ contract Contract {
         .unwrap();
 
     let result = project.paths().clone().with_language::<SolcLanguage>().flatten(target.as_path());
-    assert!(result.is_ok());
-
-    let result = result.unwrap();
-    assert_eq!(
-        result,
-        r"// SPDX-License-Identifier: UNLICENSED
-pragma solidity ^0.8.10;
-
-// src/Lib.sol
-
-library Lib {}
-
-// src/Contract.sol
-
-// Intentionally erroneous code
-contract Contract {
-    failure();
-}
-"
-    );
+    assert!(result.is_err());
+    println!("{}", result.unwrap_err());
 }
 
 #[test]

crates/core/src/error.rs

@@ -27,6 +27,8 @@ pub enum SolcError {
     /// Errors related to the Solc executable itself.
     #[error("solc exited with {0}\n{1}")]
     SolcError(std::process::ExitStatus, String),
+    #[error("failed to parse a file: {0}")]
+    ParseError(String),
     #[error("invalid UTF-8 in Solc output")]
     InvalidUtf8,
     #[error("missing pragma from Solidity file")]