feat(solc): add helper functions to compile standalone files (#931)

ethers-solc/src/lib.rs

@@ -235,6 +235,49 @@ impl<T: ArtifactOutput> Project<T> {
         project::ProjectCompiler::with_sources(self, sources)?.compile()
     }
 
+    /// Convenience function to compile a single solidity file with the project's settings.
+    /// Same as [`Self::svm_compile()`] but with the given `file` as input.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use ethers_solc::Project;
+    /// # fn demo(project: Project) {
+    /// let project = Project::builder().build().unwrap();
+    /// let output = project.compile_file("example/Greeter.sol").unwrap();
+    /// # }
+    /// ```
+    #[cfg(all(feature = "svm", feature = "async"))]
+    pub fn compile_file(&self, file: impl Into<PathBuf>) -> Result<ProjectCompileOutput<T>> {
+        let file = file.into();
+        let source = Source::read(&file)?;
+        project::ProjectCompiler::with_sources(self, Sources::from([(file, source)]))?.compile()
+    }
+
+    /// Convenience function to compile a series of solidity files with the project's settings.
+    /// Same as [`Self::svm_compile()`] but with the given `files` as input.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use ethers_solc::Project;
+    /// # fn demo(project: Project) {
+    /// let project = Project::builder().build().unwrap();
+    /// let output = project
+    ///     .compile_files(
+    ///         vec!["examples/Foo.sol", "examples/Bar.sol"]
+    ///     ).unwrap();
+    /// # }
+    /// ```
+    #[cfg(all(feature = "svm", feature = "async"))]
+    pub fn compile_files<P, I>(&self, files: I) -> Result<ProjectCompileOutput<T>>
+    where
+        I: IntoIterator<Item = P>,
+        P: Into<PathBuf>,
+    {
+        project::ProjectCompiler::with_sources(self, Source::read_all(files)?)?.compile()
+    }
+
     /// Compiles the given source files with the exact `Solc` executable
     ///
     /// First all libraries for the sources are resolved by scanning all their imports.

ethers-solc/src/project_util.rs

@@ -154,12 +154,20 @@ impl<T: ArtifactOutput> TempProject<T> {
         create_contract_file(lib, content)
     }
 
-    /// Adds a new source file
+    /// Adds a new source file inside the project's source dir
     pub fn add_source(&self, name: impl AsRef<str>, content: impl AsRef<str>) -> Result<PathBuf> {
         let name = contract_file_name(name);
         let source = self.paths().sources.join(name);
         create_contract_file(source, content)
     }
+
+    /// Adds a solidity contract in the project's root dir.
+    /// This will also create all intermediary dirs.
+    pub fn add_contract(&self, name: impl AsRef<str>, content: impl AsRef<str>) -> Result<PathBuf> {
+        let name = contract_file_name(name);
+        let source = self.root().join(name);
+        create_contract_file(source, content)
+    }
 }
 
 impl<T: ArtifactOutput + Default> TempProject<T> {

ethers-solc/tests/project.rs

@@ -454,3 +454,39 @@ fn can_detect_type_error() {
     let compiled = project.compile().unwrap();
     assert!(compiled.has_compiler_errors());
 }
+
+#[test]
+fn can_compile_single_files() {
+    let tmp = TempProject::dapptools().unwrap();
+
+    let foo = tmp
+        .add_contract(
+            "examples/Foo",
+            r#"
+    pragma solidity ^0.8.10;
+
+    contract Foo {}
+   "#,
+        )
+        .unwrap();
+
+    let compiled = tmp.project().compile_file(foo.clone()).unwrap();
+    assert!(!compiled.has_compiler_errors());
+    assert!(compiled.find("Foo").is_some());
+
+    let bar = tmp
+        .add_contract(
+            "examples/Bar",
+            r#"
+    pragma solidity ^0.8.10;
+
+    contract Bar {}
+   "#,
+        )
+        .unwrap();
+
+    let compiled = tmp.project().compile_files(vec![foo, bar]).unwrap();
+    assert!(!compiled.has_compiler_errors());
+    assert!(compiled.find("Foo").is_some());
+    assert!(compiled.find("Bar").is_some());
+}