feat: scarb fmt a single file

scarb/src/bin/scarb/args.rs

@@ -4,6 +4,7 @@
 
 use std::collections::BTreeMap;
 use std::ffi::OsString;
+use std::path::PathBuf;
 
 use anyhow::Result;
 use camino::Utf8PathBuf;
@@ -341,6 +342,8 @@ pub struct FmtArgs {
     /// Specify package(s) to format.
     #[command(flatten)]
     pub packages_filter: PackagesFilter,
+    #[clap(value_name = "TARGET")]
+    pub target: Option<PathBuf>,
 }
 
 /// Arguments accepted by the `add` command.

scarb/src/bin/scarb/commands/fmt.rs

@@ -29,6 +29,7 @@ pub fn run(args: FmtArgs, config: &Config) -> Result<()> {
             packages,
             action,
             color: !args.no_color,
+            target_file: args.target,
         },
         &ws,
     )? {

scarb/src/ops/fmt.rs

@@ -34,6 +34,7 @@ pub struct FmtOptions {
     pub action: FmtAction,
     pub packages: Vec<PackageId>,
     pub color: bool,
+    pub target_file: Option<PathBuf>,
 }
 
 #[tracing::instrument(skip_all, level = "debug")]
@@ -42,6 +43,10 @@ pub fn format(opts: FmtOptions, ws: &Workspace<'_>) -> Result<bool> {
 
     let all_correct = AtomicBool::new(true);
 
+    if let Some(target_file) = &opts.target_file {
+        return format_single_file(target_file, &opts, ws, &all_correct);
+    }
+
     for package_id in opts.packages.iter() {
         let package = ws.fetch_package(package_id)?;
 
@@ -66,6 +71,28 @@ pub fn format(opts: FmtOptions, ws: &Workspace<'_>) -> Result<bool> {
     Ok(result)
 }
 
+fn format_single_file(
+    target_file: &Path,
+    opts: &FmtOptions,
+    ws: &Workspace<'_>,
+    all_correct: &AtomicBool,
+) -> Result<bool> {
+    let config = FormatterConfig::default();
+    let fmt = CairoFormatter::new(config);
+
+    let success = match &opts.action {
+        FmtAction::Fix => format_file_in_place(&fmt, opts, ws, target_file),
+        FmtAction::Check => check_file_formatting(&fmt, opts, ws, target_file),
+        FmtAction::Emit(target) => emit_formatted_file(&fmt, target, ws, target_file),
+    };
+
+    if !success {
+        all_correct.store(false, Ordering::Release);
+    }
+
+    Ok(all_correct.load(Ordering::Acquire))
+}
+
 struct PathFormatter<'t> {
     all_correct: &'t AtomicBool,
     opts: &'t FmtOptions,

scarb/tests/fmt.rs

@@ -178,33 +178,33 @@ fn format_with_import_sorting() {
         .write_str(indoc! {"\
             use openzeppelin::introspection::interface;
             use openzeppelin::introspection::first;
-            
+
             #[starknet::contract]
             mod SRC5 {
                 use openzeppelin::introspection::interface;
                 use openzeppelin::introspection::{interface, AB};
-            
+
                 #[storage]
                 struct Storage {
                     supported_interfaces: LegacyMap<felt252, bool>
                 }
-            
+
                 use openzeppelin::introspection::first;
-            
+
                 mod A {}
                 mod G;
                 mod F;
-            
+
                 #[abi(embed_v0)]
                 impl SRC5Impl of interface::ISRC5<ContractState> {
                     fn supports_interface(self: @ContractState, interface_id: felt252) -> bool {
                         true
                     }
                 }
-            
+
                 use A;
                 use starknet::ArrayTrait;
-            
+
                 mod Inner {
                     use C;
                     use B;
@@ -227,7 +227,7 @@ fn format_with_import_sorting() {
        +use openzeppelin::introspection::first;
         use openzeppelin::introspection::interface;
        -use openzeppelin::introspection::first;
-       
+
         #[starknet::contract]
         mod SRC5 {
        +    mod F;
@@ -239,25 +239,25 @@ fn format_with_import_sorting() {
             use openzeppelin::introspection::interface;
             use openzeppelin::introspection::{interface, AB};
        +    use starknet::ArrayTrait;
-       
+
             #[storage]
             struct Storage {
        @@ -11,11 +18,7 @@
                 supported_interfaces: LegacyMap<felt252, bool>
             }
-       
+
        -    use openzeppelin::introspection::first;
        -
             mod A {}
        -    mod G;
        -    mod F;
-       
+
             #[abi(embed_v0)]
             impl SRC5Impl of interface::ISRC5<ContractState> {
        @@ -24,11 +27,8 @@
                 }
             }
-       
+
        -    use A;
        -    use starknet::ArrayTrait;
        -
@@ -267,7 +267,7 @@ fn format_with_import_sorting() {
        -        use B;
             }
         }
-       
+
        "});
 }
 
@@ -398,3 +398,28 @@ fn workspace_emit_with_root() {
     let content = t.child("second/src/lib.cairo").read_to_string();
     assert_eq!(content, SIMPLE_ORIGINAL);
 }
+
+#[test]
+fn format_specific_file() {
+    let t = build_temp_dir(SIMPLE_ORIGINAL);
+
+    // Create two files: one to be formatted and one to be left alone
+    t.child("src/lib.cairo").write_str(SIMPLE_ORIGINAL).unwrap();
+    t.child("src/other.cairo").write_str(SIMPLE_ORIGINAL).unwrap();
+
+    // Format only the lib.cairo file
+    Scarb::quick_snapbox()
+        .arg("fmt")
+        .arg("src/lib.cairo")
+        .current_dir(&t)
+        .assert()
+        .success();
+
+    // Check that lib.cairo was formatted
+    let lib_content = t.child("src/lib.cairo").read_to_string();
+    assert_eq!(lib_content, SIMPLE_FORMATTED);
+
+    // Check that other.cairo was not formatted
+    let other_content = t.child("src/other.cairo").read_to_string();
+    assert_eq!(other_content, SIMPLE_ORIGINAL);
+}