ethers-solc: fix build info default directory (#1458)

* ethers-solc: fix build info default directory

This commit fixes the default behavior for the `build-info`
directory when it is unconfigured. It should end up in
the configured artifacts directory, taking into account
whatever the config for the artifacts directory is.
If the build info is specifically configured, then that
will take precendence over the default.

* chore: add changelog entry

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Unreleased
 
+- Fix the default config for generated `BuildInfo` [#1458](https://github.com/gakonst/ethers-rs/pull/1458)
 - Allow configuration of the output directory of the generated `BuildInfo` [#1433](https://github.com/gakonst/ethers-rs/pull/1433)
 - capture unknown fields in `Block` and `Transaction` type via new `OtherFields` type [#1423](https://github.com/gakonst/ethers-rs/pull/1423)
 - Methods like `set_to()` from `TypedTransaction` can be chained

ethers-solc/src/config.rs

@@ -570,17 +570,15 @@ impl ProjectPathsConfigBuilder {
         let root = utils::canonicalized(root);
 
         let libraries = self.libraries.unwrap_or_else(|| ProjectPathsConfig::find_libs(&root));
+        let artifacts =
+            self.artifacts.unwrap_or_else(|| ProjectPathsConfig::find_artifacts_dir(&root));
 
         ProjectPathsConfig {
             cache: self
                 .cache
                 .unwrap_or_else(|| root.join("cache").join(SOLIDITY_FILES_CACHE_FILENAME)),
-            artifacts: self
-                .artifacts
-                .unwrap_or_else(|| ProjectPathsConfig::find_artifacts_dir(&root)),
-            build_infos: self.build_infos.unwrap_or_else(|| {
-                ProjectPathsConfig::find_artifacts_dir(&root).join("build-info")
-            }),
+            build_infos: self.build_infos.unwrap_or_else(|| artifacts.join("build-info")),
+            artifacts,
             sources: self.sources.unwrap_or_else(|| ProjectPathsConfig::find_source_dir(&root)),
             tests: self.tests.unwrap_or_else(|| root.join("test")),
             scripts: self.scripts.unwrap_or_else(|| root.join("script")),
@@ -776,4 +774,21 @@ mod tests {
             vec![utils::canonicalized(lib)],
         );
     }
+
+    #[test]
+    fn can_have_sane_build_info_default() {
+        let root = crate::utils::tempdir("root").unwrap();
+        let root = root.path();
+        let artifacts = root.join("forge-artifacts");
+
+        // Set the artifacts directory without setting the
+        // build info directory
+        let project = ProjectPathsConfig::builder().artifacts(&artifacts).build_with_root(&root);
+
+        // The artifacts should be set correctly based on the configured value
+        assert_eq!(project.artifacts, utils::canonicalized(artifacts));
+
+        // The build infos should by default in the artifacts directory
+        assert_eq!(project.build_infos, utils::canonicalized(project.artifacts.join("build-info")));
+    }
 }