fix: pass partial artifact cache to project compiler output (#623)

* fix: pass partial artifact cache to project compiler output

If the cache contains some artifacts but not all, the
project compiler output now contains the cached artifacts
in addition to the newly compiled artifacts.

* chore: update changelog

* fix: remove missing cache files before getting changed files

* fix: propagate error if reading cached artifacts fails

CHANGELOG.md

@@ -9,6 +9,9 @@
   [597](https://github.com/gakonst/ethers-rs/pull/597)
 - Implement hex display format for `ethers::core::Bytes` [#624](https://github.com/gakonst/ethers-rs/pull/624).
 
+## ethers-solc
+- Return cached artifacts from project `compile` when the cache only contains some files
+
 ### Unreleased
 
 ### 0.6.0

ethers-solc/src/lib.rs

@@ -8,9 +8,11 @@ use std::collections::btree_map::Entry;
 pub mod cache;
 
 mod compile;
+
 pub use compile::*;
 
 mod config;
+
 pub use config::{
     AllowedLibPaths, Artifact, ArtifactOutput, MinimalCombinedArtifacts, ProjectPathsConfig,
     SolcConfig,
@@ -22,6 +24,7 @@ use crate::{artifacts::Source, cache::SolFilesCache};
 
 pub mod error;
 pub mod utils;
+
 use crate::artifacts::Sources;
 use error::Result;
 use std::{
@@ -248,22 +251,28 @@ impl<Artifacts: ArtifactOutput> Project<Artifacts> {
         }
 
         // If there's a cache set, filter to only re-compile the files which were changed
-        let sources = if self.cached && self.paths.cache.exists() {
-            let cache = SolFilesCache::read(&self.paths.cache)?;
+        let (sources, cached_artifacts) = if self.cached && self.paths.cache.exists() {
+            let mut cache = SolFilesCache::read(&self.paths.cache)?;
+            cache.remove_missing_files();
             let changed_files = cache.get_changed_or_missing_artifacts_files::<Artifacts>(
                 sources,
                 Some(&self.solc_config),
                 &self.paths.artifacts,
             );
 
+            let cached_artifacts = if self.paths.artifacts.exists() {
+                cache.read_artifacts::<Artifacts>(&self.paths.artifacts)?
+            } else {
+                BTreeMap::default()
+            };
             // if nothing changed and all artifacts still exist
             if changed_files.is_empty() {
-                let artifacts = cache.read_artifacts::<Artifacts>(&self.paths.artifacts)?;
-                return Ok(ProjectCompileOutput::from_unchanged(artifacts))
+                return Ok(ProjectCompileOutput::from_unchanged(cached_artifacts))
             }
-            changed_files
+            // There are changed files and maybe some cached files
+            (changed_files, cached_artifacts)
         } else {
-            sources
+            (sources, BTreeMap::default())
         };
 
         // replace absolute path with source name to make solc happy
@@ -303,7 +312,11 @@ impl<Artifacts: ArtifactOutput> Project<Artifacts> {
         if !self.no_artifacts {
             Artifacts::on_output(&output, &self.paths)?;
         }
-        Ok(ProjectCompileOutput::from_compiler_output(output, self.ignored_error_codes.clone()))
+        Ok(ProjectCompileOutput::from_compiler_output_and_cache(
+            output,
+            cached_artifacts,
+            self.ignored_error_codes.clone(),
+        ))
     }
 }
 
@@ -512,6 +525,14 @@ impl<T: ArtifactOutput> ProjectCompileOutput<T> {
         }
     }
 
+    pub fn from_compiler_output_and_cache(
+        compiler_output: CompilerOutput,
+        cache: BTreeMap<PathBuf, T::Artifact>,
+        ignored_error_codes: Vec<u64>,
+    ) -> Self {
+        Self { compiler_output: Some(compiler_output), artifacts: cache, ignored_error_codes }
+    }
+
     /// Get the (merged) solc compiler output
     /// ```no_run
     /// use std::collections::BTreeMap;
@@ -648,7 +669,6 @@ impl<T: ArtifactOutput> fmt::Display for ProjectCompileOutput<T> {
 
 #[cfg(test)]
 mod tests {
-
     #[test]
     #[cfg(all(feature = "svm", feature = "async"))]
     fn test_build_all_versions() {

ethers-solc/test-data/cache-sample/NewContract.sol

@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+pragma solidity >=0.6.6;
+
+contract NewContract {
+}

ethers-solc/tests/project.rs

@@ -1,7 +1,10 @@
 //! project tests
 
 use ethers_solc::{cache::SOLIDITY_FILES_CACHE_FILENAME, Project, ProjectPathsConfig};
-use std::path::PathBuf;
+use std::{
+    io,
+    path::{Path, PathBuf},
+};
 use tempdir::TempDir;
 
 #[test]
@@ -75,3 +78,67 @@ fn can_compile_dapp_sample() {
     assert!(compiled.find("Dapp").is_some());
     assert!(!compiled.is_unchanged());
 }
+
+#[test]
+fn can_compile_dapp_sample_with_cache() {
+    let tmp_dir = TempDir::new("root").unwrap();
+    let root = tmp_dir.path();
+    let cache = root.join("cache").join(SOLIDITY_FILES_CACHE_FILENAME);
+    let artifacts = root.join("out");
+
+    let manifest_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    let orig_root = manifest_dir.join("test-data/dapp-sample");
+    let new_file = manifest_dir.join("test-data/cache-sample/NewContract.sol");
+    copy_dir_all(orig_root, &tmp_dir).unwrap();
+    let paths = ProjectPathsConfig::builder()
+        .cache(cache)
+        .sources(root.join("src"))
+        .artifacts(artifacts)
+        .lib(root.join("lib"))
+        .root(root)
+        .build()
+        .unwrap();
+
+    // first compile
+    let project = Project::builder().paths(paths).build().unwrap();
+    let compiled = project.compile().unwrap();
+    assert!(compiled.find("Dapp").is_some());
+    assert!(!compiled.has_compiler_errors());
+
+    // cache is used when nothing to compile
+    let compiled = project.compile().unwrap();
+    assert!(compiled.find("Dapp").is_some());
+    assert!(compiled.is_unchanged());
+
+    // deleted artifacts cause recompile even with cache
+    std::fs::remove_dir_all(&project.paths.artifacts).unwrap();
+    let compiled = project.compile().unwrap();
+    assert!(compiled.find("Dapp").is_some());
+    assert!(!compiled.is_unchanged());
+
+    // new file is compiled even with partial cache
+    std::fs::copy(new_file, root.join("src/NewContract.sol")).unwrap();
+    let compiled = project.compile().unwrap();
+    assert!(compiled.find("Dapp").is_some());
+    assert!(compiled.find("NewContract").is_some());
+    assert!(!compiled.is_unchanged());
+
+    // deleted artifact is not taken from the cache
+    std::fs::remove_file(&project.paths.sources.join("Dapp.sol")).unwrap();
+    let compiled = project.compile().unwrap();
+    assert!(compiled.find("Dapp").is_none());
+}
+
+fn copy_dir_all(src: impl AsRef<Path>, dst: impl AsRef<Path>) -> io::Result<()> {
+    std::fs::create_dir_all(&dst)?;
+    for entry in std::fs::read_dir(src)? {
+        let entry = entry?;
+        let ty = entry.file_type()?;
+        if ty.is_dir() {
+            copy_dir_all(entry.path(), dst.as_ref().join(entry.file_name()))?;
+        } else {
+            std::fs::copy(entry.path(), dst.as_ref().join(entry.file_name()))?;
+        }
+    }
+    Ok(())
+}