feat(formatter): Experimental sort-imports base

Author: leaysgur

crates/oxc_formatter/examples/sort_imports.rs

@@ -0,0 +1,66 @@
+#![expect(clippy::print_stdout)]
+
+use std::{fs, path::Path};
+
+use oxc_allocator::Allocator;
+use oxc_formatter::{FormatOptions, Formatter, SortImports};
+use oxc_parser::{ParseOptions, Parser};
+use oxc_span::SourceType;
+use pico_args::Arguments;
+
+/// Format a JavaScript or TypeScript file
+fn main() -> Result<(), String> {
+    let mut args = Arguments::from_env();
+    let show_ir = args.contains("--ir");
+    let name = args.free_from_str().unwrap_or_else(|_| "test.js".to_string());
+
+    // Read source file
+    let path = Path::new(&name);
+    let source_text = fs::read_to_string(path).map_err(|_| format!("Missing '{name}'"))?;
+    let source_type = SourceType::from_path(path).unwrap();
+    let allocator = Allocator::new();
+
+    // Parse the source code
+    let ret = Parser::new(&allocator, &source_text, source_type)
+        .with_options(ParseOptions {
+            parse_regular_expression: false,
+            // Enable all syntax features
+            allow_v8_intrinsics: true,
+            allow_return_outside_function: true,
+            // `oxc_formatter` expects this to be false
+            preserve_parens: false,
+        })
+        .parse();
+
+    // Report any parsing errors
+    for error in ret.errors {
+        let error = error.with_source_code(source_text.clone());
+        println!("{error:?}");
+        println!("Parsed with Errors.");
+    }
+
+    // Format the parsed code
+    let options = FormatOptions {
+        experimental_sort_imports: Some(SortImports {
+            partition_by_newline: true,
+            partition_by_comment: false,
+            sort_side_effects: true,
+        }),
+        ..Default::default()
+    };
+
+    let formatter = Formatter::new(&allocator, options);
+    if show_ir {
+        let doc = formatter.doc(&ret.program);
+        println!("[");
+        for el in doc.iter() {
+            println!("  {el:?},");
+        }
+        println!("]");
+    } else {
+        let code = formatter.build(&ret.program);
+        println!("{code}");
+    }
+
+    Ok(())
+}

crates/oxc_formatter/src/formatter/mod.rs

@@ -105,6 +105,12 @@ impl<'a> Formatted<'a> {
     }
 }
 
+impl<'a> Formatted<'a> {
+    pub fn apply_transform(&mut self, transform: impl FnOnce(&Document<'a>) -> Document<'a>) {
+        self.document = transform(&self.document);
+    }
+}
+
 impl Formatted<'_> {
     pub fn print(&self) -> PrintResult<Printed> {
         let print_options = self.context.options().as_print_options();

crates/oxc_formatter/src/ir_transform/mod.rs

@@ -0,0 +1,3 @@
+mod sort_imports;
+
+pub use sort_imports::SortImportsTransform;

crates/oxc_formatter/src/ir_transform/sort_imports.rs

@@ -0,0 +1,32 @@
+use crate::{formatter::format_element::document::Document, options::SortImports};
+
+pub struct SortImportsTransform {
+    options: SortImports,
+}
+
+impl SortImportsTransform {
+    pub fn new(options: SortImports) -> Self {
+        Self { options }
+    }
+
+    pub fn transform<'a>(&self, document: &Document<'a>) -> Document<'a> {
+        let mut new_elements = Vec::with_capacity(document.len());
+
+        // TODO: THESE ARE DUMMY IMPLEMENTATIONS!
+        let mut temp = None;
+        for (idx, element) in document.iter().enumerate() {
+            if idx == 0 {
+                temp = Some(element);
+                continue;
+            }
+
+            new_elements.push(element.clone());
+        }
+
+        if let Some(temp) = temp {
+            new_elements.insert(new_elements.len() - 1, temp.clone());
+        }
+
+        Document::from(new_elements)
+    }
+}

crates/oxc_formatter/src/lib.rs

@@ -14,6 +14,7 @@ mod generated {
     mod format;
 }
 mod formatter;
+mod ir_transform;
 mod options;
 mod parentheses;
 mod service;
@@ -38,6 +39,7 @@ pub use crate::service::source_type::get_supported_source_type;
 use crate::{
     formatter::{FormatContext, Formatted, format_element::document::Document},
     generated::ast_nodes::{AstNode, AstNodes},
+    ir_transform::SortImportsTransform,
 };
 
 use self::formatter::prelude::tag::Label;
@@ -71,13 +73,25 @@ impl<'a> Formatter<'a> {
 
         let source_text = program.source_text;
         self.source_text = source_text;
+
+        let experimental_sort_imports = self.options.experimental_sort_imports;
+
         let context = FormatContext::new(program, self.allocator, self.options);
-        formatter::format(
+        let mut formatted = formatter::format(
             program,
             context,
             formatter::Arguments::new(&[formatter::Argument::new(&program_node)]),
         )
-        .unwrap()
+        .unwrap();
+
+        // Basic formatting and `document.propagate_expand()` are already done here.
+        // Now apply additional transforms if enabled.
+        if let Some(sort_imports_options) = experimental_sort_imports {
+            let sort_imports = SortImportsTransform::new(sort_imports_options);
+            formatted.apply_transform(|doc| sort_imports.transform(doc));
+        }
+
+        formatted
     }
 }
 

crates/oxc_formatter/src/options.rs

@@ -62,6 +62,10 @@ pub struct FormatOptions {
     /// - `"start"`: Places the operator at the beginning of the next line.
     /// - `"end"`: Places the operator at the end of the current line (default).
     pub experimental_operator_position: OperatorPosition,
+
+    // TODO: `FormatOptions`? Split out as `TransformOptions`?
+    /// Sort import statements. By default disabled.
+    pub experimental_sort_imports: Option<SortImports>,
 }
 
 impl FormatOptions {
@@ -82,6 +86,7 @@ impl FormatOptions {
             attribute_position: AttributePosition::default(),
             expand: Expand::default(),
             experimental_operator_position: OperatorPosition::default(),
+            experimental_sort_imports: None,
         }
     }
 
@@ -106,7 +111,8 @@ impl fmt::Display for FormatOptions {
         writeln!(f, "Bracket same line: {}", self.bracket_same_line.value())?;
         writeln!(f, "Attribute Position: {}", self.attribute_position)?;
         writeln!(f, "Expand lists: {}", self.expand)?;
-        writeln!(f, "Experimental operator position: {}", self.experimental_operator_position)
+        writeln!(f, "Experimental operator position: {}", self.experimental_operator_position)?;
+        writeln!(f, "Experimental sort imports: {:?}", self.experimental_sort_imports)
     }
 }
 
@@ -908,3 +914,13 @@ impl fmt::Display for OperatorPosition {
         f.write_str(s)
     }
 }
+
+#[derive(Clone, Copy, Debug, Default, Eq, Hash, PartialEq)]
+pub struct SortImports {
+    /// Partition imports by newlines.
+    pub partition_by_newline: bool,
+    /// Partition imports by comments.
+    pub partition_by_comment: bool,
+    /// Sort side effects imports.
+    pub sort_side_effects: bool,
+}