refactor(abigen): Abigen, ContractBindings (#2019)

* use format_ident

* lib.rs

* refactor: ContractBindings

* refactor: from_file

* add write_fmt

* mv

* error msg

* revert mod docs

ethers-contract/ethers-contract-abigen/src/contract.rs

@@ -1,4 +1,5 @@
-#![deny(missing_docs)]
+//! Contains types to generate Rust bindings for Solidity contracts.
+
 mod common;
 mod errors;
 mod events;
@@ -15,7 +16,7 @@ use ethers_core::{
 };
 use eyre::{eyre, Context as _, Result};
 use proc_macro2::{Ident, Literal, TokenStream};
-use quote::quote;
+use quote::{format_ident, quote};
 use serde::Deserialize;
 use std::collections::BTreeMap;
 use syn::Path;
@@ -183,7 +184,7 @@ impl Context {
     pub fn from_abigen(args: Abigen) -> Result<Self> {
         // get the actual ABI string
         let mut abi_str =
-            args.abi_source.get().map_err(|e| eyre!("failed to get ABI JSON: {}", e))?;
+            args.abi_source.get().map_err(|e| eyre!("failed to get ABI JSON: {e}"))?;
 
         // holds the bytecode parsed from the abi_str, if present
         let mut contract_bytecode = None;
@@ -234,7 +235,7 @@ impl Context {
             };
 
             if method_aliases.insert(signature.clone(), alias).is_some() {
-                eyre::bail!("duplicate method signature '{}' in method aliases", signature)
+                eyre::bail!("duplicate method signature {signature:?} in method aliases")
             }
         }
 
@@ -293,27 +294,27 @@ impl Context {
         })
     }
 
-    /// The initial name fo the contract
+    /// The name of the contract.
     pub(crate) fn contract_name(&self) -> &str {
         &self.contract_name
     }
 
-    /// name of the `Lazy` that stores the ABI
+    /// Name of the `Lazy` that stores the ABI.
     pub(crate) fn inline_abi_ident(&self) -> Ident {
-        util::safe_ident(&format!("{}_ABI", self.contract_ident.to_string().to_uppercase()))
+        format_ident!("{}_ABI", self.contract_name.to_uppercase())
     }
 
-    /// name of the `Lazy` that stores the Bytecode
+    /// Name of the `Lazy` that stores the Bytecode.
     pub(crate) fn inline_bytecode_ident(&self) -> Ident {
-        util::safe_ident(&format!("{}_BYTECODE", self.contract_ident.to_string().to_uppercase()))
+        format_ident!("{}_BYTECODE", self.contract_name.to_uppercase())
     }
 
-    /// The internal abi struct mapping table
+    /// Returns a reference to the internal ABI struct mapping table.
     pub fn internal_structs(&self) -> &InternalStructs {
         &self.internal_structs
     }
 
-    /// The internal mutable abi struct mapping table
+    /// Returns a mutable reference to the internal ABI struct mapping table.
     pub fn internal_structs_mut(&mut self) -> &mut InternalStructs {
         &mut self.internal_structs
     }

ethers-contract/ethers-contract-abigen/src/lib.rs

@@ -15,27 +15,28 @@
 #[path = "test/macros.rs"]
 mod test_macros;
 
-/// Contains types to generate rust bindings for solidity contracts
 pub mod contract;
 pub use contract::structs::InternalStructs;
-use contract::Context;
-
-mod source;
-mod util;
 
 pub mod filter;
 pub use filter::{ContractFilter, ExcludeContracts, SelectContracts};
+
 pub mod multi;
 pub use multi::MultiAbigen;
 
-pub use ethers_core::types::Address;
+mod source;
 pub use source::Source;
+
+mod util;
 pub use util::parse_address;
 
-use crate::contract::ExpandedContract;
+pub use ethers_core::types::Address;
-use eyre::Result;
+
+use contract::{Context, ExpandedContract};
+use eyre::{Context as _, Result};
 use proc_macro2::TokenStream;
-use std::{collections::HashMap, fs::File, io::Write, path::Path};
+use quote::ToTokens;
+use std::{collections::HashMap, fmt, fs, io, path::Path};
 
 /// Programmatically generate type-safe Rust bindings for an Ethereum smart contract from its ABI.
 ///
@@ -101,18 +102,18 @@ impl Abigen {
 
     /// Attempts to load a new builder from an ABI JSON file at the specific path.
     pub fn from_file(path: impl AsRef<Path>) -> Result<Self> {
-        let name = path
+        let path = dunce::canonicalize(path).wrap_err("File does not exist")?;
-            .as_ref()
+        // this shouldn't error when the path is canonicalized
-            .file_stem()
+        let file_name = path.file_name().ok_or_else(|| eyre::eyre!("Invalid path"))?;
-            .ok_or_else(|| eyre::format_err!("Missing file stem in path"))?
+        let name = file_name
             .to_str()
-            .ok_or_else(|| eyre::format_err!("Unable to convert file stem to string"))?;
+            .ok_or_else(|| eyre::eyre!("File name contains invalid UTF-8"))?
+            .split('.') // ignore everything after the first `.`
+            .next()
+            .unwrap(); // file_name is not empty as asserted by .file_name() already
+        let contents = fs::read_to_string(&path).wrap_err("Could not read file")?;
 
-        // test,script files usually end with `.t.sol` or `.s.sol`, we simply cut off everything
+        Self::new(name, contents)
-        // after the first `.`
-        let name = name.split('.').next().expect("name not empty.");
-
-        Self::new(name, std::fs::read_to_string(path.as_ref())?)
     }
 
     /// Manually adds a solidity event alias to specify what the event struct and function name will
@@ -200,63 +201,87 @@ impl Abigen {
     }
 }
 
-/// Type-safe contract bindings generated by a `Builder`. This type can be
+/// Type-safe contract bindings generated by `Abigen`.
-/// either written to file or into a token stream for use in a procedural macro.
+///
+/// This type can be either written to file or converted to a token stream for a procedural macro.
+#[derive(Clone)]
 pub struct ContractBindings {
-    /// The TokenStream representing the contract bindings.
+    /// The contract's name.
-    tokens: TokenStream,
+    pub name: String,
-    /// The output options used for serialization.
+
-    format: bool,
+    /// The generated bindings as a `TokenStream`.
-    /// The contract name
+    pub tokens: TokenStream,
-    name: String,
+
+    /// Whether to format the generated bindings using [`prettyplease`].
+    pub format: bool,
+}
+
+impl ToTokens for ContractBindings {
+    fn into_token_stream(self) -> TokenStream {
+        self.tokens
+    }
+
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        tokens.extend(Some(self.tokens.clone()))
+    }
+
+    fn to_token_stream(&self) -> TokenStream {
+        self.tokens.clone()
+    }
+}
+
+impl fmt::Display for ContractBindings {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if self.format {
+            let syntax_tree = syn::parse2::<syn::File>(self.tokens.clone()).unwrap();
+            let s = prettyplease::unparse(&syntax_tree);
+            f.write_str(&s)
+        } else {
+            fmt::Display::fmt(&self.tokens, f)
+        }
+    }
+}
+
+impl fmt::Debug for ContractBindings {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("ContractBindings")
+            .field("name", &self.name)
+            .field("format", &self.format)
+            .finish()
+    }
 }
 
 impl ContractBindings {
-    /// Writes the bindings to a given `Write`.
+    /// Writes the bindings to a new Vec.
-    pub fn write<W>(&self, mut w: W) -> Result<()>
+    pub fn to_vec(&self) -> Vec<u8> {
-    where
+        self.to_string().into_bytes()
-        W: Write,
-    {
-        let source = if self.format {
-            let syntax_tree = syn::parse2::<syn::File>(self.tokens.clone()).unwrap();
-            prettyplease::unparse(&syntax_tree)
-        } else {
-            self.tokens.to_string()
-        };
-
-        w.write_all(source.as_bytes())?;
-        Ok(())
     }
 
-    /// Writes the bindings to a new Vec. Panics if unable to allocate
+    /// Writes the bindings to a given `io::Write`.
-    pub fn to_vec(&self) -> Vec<u8> {
+    pub fn write(&self, w: &mut impl io::Write) -> io::Result<()> {
-        let mut bindings = vec![];
+        let tokens = self.to_string();
-        self.write(&mut bindings).expect("allocations don't fail");
+        w.write_all(tokens.as_bytes())
-        bindings
+    }
+
+    /// Writes the bindings to a given `fmt::Write`.
+    pub fn write_fmt(&self, w: &mut impl fmt::Write) -> fmt::Result {
+        let tokens = self.to_string();
+        w.write_str(&tokens)
     }
 
     /// Writes the bindings to the specified file.
-    pub fn write_to_file<P>(&self, path: P) -> Result<()>
+    pub fn write_to_file(&self, file: impl AsRef<Path>) -> io::Result<()> {
-    where
+        fs::write(file.as_ref(), self.to_string())
-        P: AsRef<Path>,
-    {
-        let file = File::create(path)?;
-        self.write(file)
     }
 
-    /// Writes the bindings to a `contract_name.rs` file in the specified
+    /// Writes the bindings to a `contract_name.rs` file in the specified directory.
-    /// directory. The filename is the snake_case transformation of the contract
+    pub fn write_module_in_dir(&self, dir: impl AsRef<Path>) -> io::Result<()> {
-    /// name.
-    pub fn write_module_in_dir<P>(&self, dir: P) -> Result<()>
-    where
-        P: AsRef<Path>,
-    {
         let file = dir.as_ref().join(self.module_filename());
         self.write_to_file(file)
     }
 
-    /// Converts the bindings into its underlying token stream. This allows it
+    #[deprecated = "Use ::quote::ToTokens::into_token_stream instead"]
-    /// to be used within a procedural macro.
+    #[doc(hidden)]
     pub fn into_tokens(self) -> TokenStream {
         self.tokens
     }
@@ -269,7 +294,7 @@ impl ContractBindings {
     /// Generate the default file name of the module.
     pub fn module_filename(&self) -> String {
         let mut name = self.module_name();
-        name.extend([".rs"]);
+        name.push_str(".rs");
         name
     }
 }

examples/contracts/examples/compile.rs

@@ -27,7 +27,7 @@ fn main() -> Result<()> {
     if let Some(output_path) = args.next() {
         bindings.write_to_file(output_path)?;
     } else {
-        bindings.write(std::io::stdout())?;
+        bindings.write(&mut std::io::stdout())?;
     }
 
     Ok(())