fix: create verifiable Standard JSON for projects with external files

src/lib.rs

@@ -490,8 +490,6 @@ impl<T: ArtifactOutput> Project<T> {
         &self,
         target: impl AsRef<Path>,
     ) -> Result<StandardJsonCompilerInput> {
-        use path_slash::PathExt;
-
         let target = target.as_ref();
         tracing::trace!("Building standard-json-input for {:?}", target);
         let graph = Graph::resolve(&self.paths)?;
@@ -514,14 +512,7 @@ impl<T: ArtifactOutput> Project<T> {
         let root = self.root();
         let sources = sources
             .into_iter()
-            .map(|(path, source)| {
-                let path: PathBuf = if let Ok(stripped) = path.strip_prefix(root) {
-                    stripped.to_slash_lossy().into_owned().into()
-                } else {
-                    path.to_slash_lossy().into_owned().into()
-                };
-                (path, source.clone())
-            })
+            .map(|(path, source)| (rebase_path(root, path), source.clone()))
             .collect();
 
         let mut settings = self.solc_config.settings.clone();
@@ -954,6 +945,62 @@ impl<T: ArtifactOutput> ArtifactOutput for Project<T> {
     }
 }
 
+// Rebases the given path to the base directory lexically.
+//
+// For instance, given the base `/home/user/project` and the path `/home/user/project/src/A.sol`,
+// this function returns `src/A.sol`.
+//
+// This function transforms a path into a form that is relative to the base directory. The returned
+// path starts either with a normal component (e.g., `src`) or a parent directory component (i.e.,
+// `..`). It also converts the path into a UTF-8 string and replaces all separators with forward
+// slashes (`/`), if they're not.
+//
+// The rebasing process can be conceptualized as follows:
+//
+// 1. Remove the leading components from the path that match those in the base.
+// 2. Prepend `..` components to the path, matching the number of remaining components in the base.
+//
+// # Examples
+//
+// `rebase_path("/home/user/project", "/home/user/project/src/A.sol")` returns `src/A.sol`. The
+// common part, `/home/user/project`, is removed from the path.
+//
+// `rebase_path("/home/user/project", "/home/user/A.sol")` returns `../A.sol`. First, the common
+// part, `/home/user`, is removed, leaving `A.sol`. Next, as `project` remains in the base, `..` is
+// prepended to the path.
+//
+// On Windows, paths like `a\b\c` are converted to `a/b/c`.
+//
+// For more examples, see the test.
+fn rebase_path(base: impl AsRef<Path>, path: impl AsRef<Path>) -> PathBuf {
+    use path_slash::PathExt;
+
+    let mut base_components = base.as_ref().components();
+    let mut path_components = path.as_ref().components();
+
+    let mut new_path = PathBuf::new();
+
+    while let Some(path_component) = path_components.next() {
+        let base_component = base_components.next();
+
+        if Some(path_component) != base_component {
+            if base_component.is_some() {
+                new_path.extend(
+                    std::iter::repeat(std::path::Component::ParentDir)
+                        .take(base_components.count() + 1),
+                );
+            }
+
+            new_path.push(path_component);
+            new_path.extend(path_components);
+
+            break;
+        }
+    }
+
+    new_path.to_slash_lossy().into_owned().into()
+}
+
 #[cfg(test)]
 #[cfg(all(feature = "svm-solc", not(target_arch = "wasm32")))]
 mod tests {
@@ -1014,4 +1061,43 @@ mod tests {
         let contracts = project.compile().unwrap().succeeded().output().contracts;
         assert_eq!(contracts.contracts().count(), 2);
     }
+
+    #[test]
+    fn can_rebase_path() {
+        assert_eq!(rebase_path("a/b", "a/b/c"), PathBuf::from("c"));
+        assert_eq!(rebase_path("a/b", "a/c"), PathBuf::from("../c"));
+        assert_eq!(rebase_path("a/b", "c"), PathBuf::from("../../c"));
+
+        assert_eq!(
+            rebase_path("/home/user/project", "/home/user/project/A.sol"),
+            PathBuf::from("A.sol")
+        );
+        assert_eq!(
+            rebase_path("/home/user/project", "/home/user/project/src/A.sol"),
+            PathBuf::from("src/A.sol")
+        );
+        assert_eq!(
+            rebase_path("/home/user/project", "/home/user/project/lib/forge-std/src/Test.sol"),
+            PathBuf::from("lib/forge-std/src/Test.sol")
+        );
+        assert_eq!(
+            rebase_path("/home/user/project", "/home/user/A.sol"),
+            PathBuf::from("../A.sol")
+        );
+        assert_eq!(rebase_path("/home/user/project", "/home/A.sol"), PathBuf::from("../../A.sol"));
+        assert_eq!(rebase_path("/home/user/project", "/A.sol"), PathBuf::from("../../../A.sol"));
+        assert_eq!(
+            rebase_path("/home/user/project", "/tmp/A.sol"),
+            PathBuf::from("../../../tmp/A.sol")
+        );
+
+        assert_eq!(
+            rebase_path("/Users/ah/temp/verif", "/Users/ah/temp/remapped/Child.sol"),
+            PathBuf::from("../remapped/Child.sol")
+        );
+        assert_eq!(
+            rebase_path("/Users/ah/temp/verif", "/Users/ah/temp/verif/../remapped/Parent.sol"),
+            PathBuf::from("../remapped/Parent.sol")
+        );
+    }
 }

tests/project.rs

@@ -12,7 +12,7 @@ use foundry_compilers::{
     info::ContractInfo,
     project_util::*,
     remappings::Remapping,
-    Artifact, CompilerInput, ConfigurableArtifacts, ExtraOutputValues, Graph, Project,
+    utils, Artifact, CompilerInput, ConfigurableArtifacts, ExtraOutputValues, Graph, Project,
     ProjectCompileOutput, ProjectPathsConfig, Solc, TestFileFilter,
 };
 use pretty_assertions::assert_eq;
@@ -1600,6 +1600,71 @@ fn can_sanitize_bytecode_hash() {
     assert!(compiled.find_first("A").is_some());
 }
 
+// https://github.com/foundry-rs/foundry/issues/5307
+#[test]
+fn can_create_standard_json_input_with_external_file() {
+    // File structure:
+    // .
+    // ├── verif
+    // │   └── src
+    // │       └── Counter.sol
+    // └── remapped
+    //     ├── Child.sol
+    //     └── Parent.sol
+
+    let dir = tempfile::tempdir().unwrap();
+    let verif_dir = utils::canonicalize(dir.path()).unwrap().join("verif");
+    let remapped_dir = utils::canonicalize(dir.path()).unwrap().join("remapped");
+    fs::create_dir_all(verif_dir.join("src")).unwrap();
+    fs::create_dir(&remapped_dir).unwrap();
+
+    let mut verif_project = Project::builder()
+        .paths(ProjectPathsConfig::dapptools(&verif_dir).unwrap())
+        .build()
+        .unwrap();
+
+    verif_project.paths.remappings.push(Remapping {
+        context: None,
+        name: "@remapped/".into(),
+        path: "../remapped/".into(),
+    });
+    verif_project.allowed_paths.insert(remapped_dir.clone());
+
+    fs::write(remapped_dir.join("Parent.sol"), "pragma solidity >=0.8.0; import './Child.sol';")
+        .unwrap();
+    fs::write(remapped_dir.join("Child.sol"), "pragma solidity >=0.8.0;").unwrap();
+    fs::write(
+        verif_dir.join("src/Counter.sol"),
+        "pragma solidity >=0.8.0; import '@remapped/Parent.sol'; contract Counter {}",
+    )
+    .unwrap();
+
+    // solc compiles using the host file system; therefore, this setup is considered valid
+    let compiled = verif_project.compile().unwrap();
+    compiled.assert_success();
+
+    // can create project root based paths
+    let std_json = verif_project.standard_json_input(verif_dir.join("src/Counter.sol")).unwrap();
+    assert_eq!(
+        std_json.sources.iter().map(|(path, _)| path.clone()).collect::<Vec<_>>(),
+        vec![
+            PathBuf::from("src/Counter.sol"),
+            PathBuf::from("../remapped/Parent.sol"),
+            PathBuf::from("../remapped/Child.sol")
+        ]
+    );
+
+    // can compile using the created json
+    let compiler_errors = Solc::default()
+        .compile(&std_json)
+        .unwrap()
+        .errors
+        .into_iter()
+        .filter_map(|e| if e.severity.is_error() { Some(e.message) } else { None })
+        .collect::<Vec<_>>();
+    assert!(compiler_errors.is_empty(), "{:?}", compiler_errors);
+}
+
 #[test]
 fn can_compile_std_json_input() {
     let tmp = TempProject::dapptools_init().unwrap();