feat(solc): Add standard-json-input (#1126)

* Add standard-json-input

* remove debugging

* Update the error message

* Remove unnecessary changes

* Refactor

* make clippy happy

* Return CompilerInput instead of String

ethers-etherscan/src/contract.rs

@@ -133,7 +133,7 @@ impl AsRef<str> for CodeFormat {
 
 impl Default for CodeFormat {
     fn default() -> Self {
-        CodeFormat::SingleFile
+        CodeFormat::StandardJsonInput
     }
 }
 

ethers-solc/src/lib.rs

@@ -50,7 +50,7 @@ pub mod project_util;
 /// Represents a project workspace and handles `solc` compiling of all contracts in that workspace.
 #[derive(Debug)]
 pub struct Project<T: ArtifactOutput = ConfigurableArtifacts> {
-    /// The layout of the
+    /// The layout of the project
     pub paths: ProjectPathsConfig,
     /// Where to find solc
     pub solc: Solc,
@@ -426,6 +426,33 @@ impl<T: ArtifactOutput> Project<T> {
     pub fn flatten(&self, target: &Path) -> Result<String> {
         self.paths.flatten(target)
     }
+
+    /// Returns standard-json-input to compile the target contract
+    pub fn standard_json_input(&self, target: &Path) -> Result<CompilerInput> {
+        tracing::trace!("Building standard-json-input");
+        let graph = Graph::resolve(&self.paths)?;
+        let target_index = graph.files().get(target).ok_or_else(|| {
+            SolcError::msg(format!("cannot resolve file at \"{:?}\"", target.display()))
+        })?;
+        let mut sources = Vec::new();
+        let (path, source) = graph.node(*target_index).unpack();
+        sources.push((path, source));
+        sources.extend(
+            graph.all_imported_nodes(*target_index).map(|index| graph.node(index).unpack()),
+        );
+
+        let compiler_inputs = CompilerInput::with_sources(
+            sources.into_iter().map(|(s, p)| (s.clone(), p.clone())).collect(),
+        );
+        let compiler_input = compiler_inputs
+            .first()
+            .ok_or_else(|| SolcError::msg("cannot get the compiler input"))?
+            .clone()
+            .settings(self.solc_config.settings.clone())
+            .with_remappings(self.paths.remappings.clone());
+
+        Ok(compiler_input)
+    }
 }
 
 pub struct ProjectBuilder<T: ArtifactOutput = ConfigurableArtifacts> {

ethers-solc/src/resolver/mod.rs

@@ -206,6 +206,11 @@ impl Graph {
         self.edges.imported_nodes(from)
     }
 
+    /// Returns an iterator that yields all imports of a node and all their imports
+    pub fn all_imported_nodes(&self, from: usize) -> impl Iterator<Item = usize> + '_ {
+        self.edges.all_imported_nodes(from)
+    }
+
     /// Returns `true` if the given node has any outgoing edges.
     pub(crate) fn has_outgoing_edges(&self, index: usize) -> bool {
         !self.edges.edges[index].is_empty()
@@ -782,6 +787,10 @@ impl Node {
     pub fn license(&self) -> &Option<SolDataUnit<String>> {
         &self.data.license
     }
+
+    pub fn unpack(&self) -> (&PathBuf, &Source) {
+        (&self.path, &self.source)
+    }
 }
 
 /// Helper type for formatting a node