feat(abigen): use prettyplease (#2027)

Cargo.lock

@@ -1378,6 +1378,7 @@ dependencies = [
  "eyre",
  "getrandom 0.2.8",
  "hex",
+ "prettyplease",
  "proc-macro2",
  "quote",
  "regex",
@@ -3162,6 +3163,16 @@ dependencies = [
  "yansi",
 ]
 
+[[package]]
+name = "prettyplease"
+version = "0.1.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e97e3215779627f01ee256d2fad52f3d95e8e1c11e9fc6fd08f7cd455d5d5c78"
+dependencies = [
+ "proc-macro2",
+ "syn",
+]
+
 [[package]]
 name = "primitive-types"
 version = "0.12.1"

ethers-contract/ethers-contract-abigen/Cargo.toml

@@ -16,10 +16,12 @@ keywords = ["ethereum", "web3", "celo", "ethers"]
 [dependencies]
 ethers-core = { version = "^1.0.0", path = "../../ethers-core", features = ["macros"] }
 
-Inflector = "0.11"
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = "1.0.12"
+syn = { version = "1.0.12", default-features = false, features = ["full"] }
+prettyplease = "0.1.23"
+
+Inflector = "0.11"
 url = "2.1"
 serde_json = "1.0.61"
 serde = { version = "1.0.124", features = ["derive"] }

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

@@ -16,7 +16,6 @@ pub mod contract;
 pub use contract::structs::InternalStructs;
 use contract::Context;
 
-mod rustfmt;
 mod source;
 mod util;
 
@@ -69,8 +68,8 @@ pub struct Abigen {
     /// Derives added to event structs and enums.
     event_derives: Vec<String>,
 
-    /// Format the code using a locally installed copy of `rustfmt`.
-    rustfmt: bool,
+    /// Whether to format the code. Uses [`prettyplease`].
+    format: bool,
 
     /// Manually specified event name aliases.
     event_aliases: HashMap<String, String>,
@@ -89,7 +88,7 @@ impl Abigen {
             method_aliases: HashMap::new(),
             event_derives: Vec::new(),
             event_aliases: HashMap::new(),
-            rustfmt: true,
+            format: true,
             error_aliases: Default::default(),
         })
     }
@@ -147,14 +146,20 @@ impl Abigen {
         self
     }
 
-    /// Specify whether or not to format the code using a locally installed copy
-    /// of `rustfmt`.
-    ///
-    /// Note that in case `rustfmt` does not exist or produces an error, the
-    /// unformatted code will be used.
     #[must_use]
+    #[deprecated = "Use format instead"]
+    #[doc(hidden)]
     pub fn rustfmt(mut self, rustfmt: bool) -> Self {
-        self.rustfmt = rustfmt;
+        self.format = rustfmt;
+        self
+    }
+
+    /// Specify whether to format the code or not. True by default.
+    ///
+    /// This will use [`prettyplease`], so the resulting formatted code **will not** be affected by
+    /// the local `rustfmt` version or config.
+    pub fn format(mut self, format: bool) -> Self {
+        self.format = format;
         self
     }
 
@@ -173,10 +178,10 @@ impl Abigen {
 
     /// Generates the contract bindings.
     pub fn generate(self) -> Result<ContractBindings> {
-        let rustfmt = self.rustfmt;
+        let format = self.format;
         let name = self.contract_name.clone();
         let (expanded, _) = self.expand()?;
-        Ok(ContractBindings { tokens: expanded.into_tokens(), rustfmt, name })
+        Ok(ContractBindings { tokens: expanded.into_tokens(), format, name })
     }
 
     /// Expands the `Abigen` and returns the [`ExpandedContract`] that holds all tokens and the
@@ -193,7 +198,7 @@ pub struct ContractBindings {
     /// The TokenStream representing the contract bindings.
     tokens: TokenStream,
     /// The output options used for serialization.
-    rustfmt: bool,
+    format: bool,
     /// The contract name
     name: String,
 }
@@ -204,14 +209,11 @@ impl ContractBindings {
     where
         W: Write,
     {
-        let source = {
-            let raw = self.tokens.to_string();
-
-            if self.rustfmt {
-                rustfmt::format(&raw).unwrap_or(raw)
-            } else {
-                raw
-            }
+        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())?;

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

@@ -139,11 +139,8 @@ impl MultiAbigen {
 
     /// Build the contract bindings and prepare for writing
     pub fn build(self) -> Result<MultiBindings> {
-        let rustfmt = self.abigens.iter().any(|gen| gen.rustfmt);
-        Ok(MultiBindings {
-            expansion: MultiExpansion::from_abigen(self.abigens)?.expand(),
-            rustfmt,
-        })
+        let format = self.abigens.iter().any(|gen| gen.format);
+        Ok(MultiBindings { expansion: MultiExpansion::from_abigen(self.abigens)?.expand(), format })
     }
 }
 
@@ -298,14 +295,14 @@ impl MultiExpansionResult {
     }
 
     /// Converts this result into [`MultiBindingsInner`]
-    fn into_bindings(mut self, single_file: bool, rustfmt: bool) -> MultiBindingsInner {
+    fn into_bindings(mut self, single_file: bool, format: bool) -> MultiBindingsInner {
         self.set_shared_import_path(single_file);
         let Self { contracts, shared_types, root, .. } = self;
         let bindings = contracts
             .into_iter()
             .map(|(expanded, ctx)| ContractBindings {
                 tokens: expanded.into_tokens(),
-                rustfmt,
+                format,
                 name: ctx.contract_name().to_string(),
             })
             .map(|v| (v.name.clone(), v))
@@ -325,7 +322,7 @@ impl MultiExpansionResult {
             };
             Some(ContractBindings {
                 tokens: shared_types,
-                rustfmt,
+                format,
                 name: "shared_types".to_string(),
             })
         } else {
@@ -364,7 +361,7 @@ impl MultiExpansionResult {
 ///     changed)
 pub struct MultiBindings {
     expansion: MultiExpansionResult,
-    rustfmt: bool,
+    format: bool,
 }
 
 impl MultiBindings {
@@ -378,18 +375,25 @@ impl MultiBindings {
         self.expansion.contracts.is_empty()
     }
 
-    /// Specify whether or not to format the code using a locally installed copy
-    /// of `rustfmt`.
-    ///
-    /// Note that in case `rustfmt` does not exist or produces an error, the
-    /// unformatted code will be used.
+    #[must_use]
+    #[deprecated = "Use format instead"]
+    #[doc(hidden)]
     pub fn rustfmt(mut self, rustfmt: bool) -> Self {
-        self.rustfmt = rustfmt;
+        self.format = rustfmt;
+        self
+    }
+
+    /// Specify whether to format the code or not. True by default.
+    ///
+    /// This will use [`prettyplease`], so the resulting formatted code **will not** be affected by
+    /// the local `rustfmt` version or config.
+    pub fn format(mut self, format: bool) -> Self {
+        self.format = format;
         self
     }
 
     fn into_inner(self, single_file: bool) -> MultiBindingsInner {
-        self.expansion.into_bindings(single_file, self.rustfmt)
+        self.expansion.into_bindings(single_file, self.format)
     }
 
     /// Generates all the bindings and writes them to the given module

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

@@ -1,36 +0,0 @@
-//! This module implements basic `rustfmt` code formatting.
-
-use eyre::{eyre, Result};
-use std::{
-    io::Write,
-    process::{Command, Stdio},
-};
-
-/// Format the raw input source string and return formatted output.
-pub fn format<S>(source: S) -> Result<String>
-where
-    S: AsRef<str>,
-{
-    let mut rustfmt =
-        Command::new("rustfmt").stdin(Stdio::piped()).stdout(Stdio::piped()).spawn()?;
-
-    {
-        let stdin = rustfmt
-            .stdin
-            .as_mut()
-            .ok_or_else(|| eyre!("stdin was not created for `rustfmt` child process"))?;
-        stdin.write_all(source.as_ref().as_bytes())?;
-    }
-
-    let output = rustfmt.wait_with_output()?;
-
-    eyre::ensure!(
-        output.status.success(),
-        "`rustfmt` exited with code {}:\n{}",
-        output.status,
-        String::from_utf8_lossy(&output.stderr),
-    );
-
-    let stdout = String::from_utf8(output.stdout)?;
-    Ok(stdout)
-}