challenge(formatter): add bracketSpacing option matching Prettier's setting

CHANGELOG.md

@@ -32,6 +32,7 @@ Read our [guidelines for writing a good changelog entry](https://github.com/biom
 #### New features
 
 - Add a new option [`--line-ending`](https://biomejs.dev/reference/configuration/#formatterlineending). This option allows changing the type of line endings. Contributed by @SuperchupuDev
+- Added a new option called `--bracket-spacing` to the formatter. This option allows you to control whether spaces are inserted around the brackets of object literals. [#627](https://github.com/biomejs/biome/issues/627). Contributed by @faultyserver
 
 #### Bug fixes
 

crates/biome_cli/tests/commands/format.rs

@@ -69,6 +69,16 @@ action => {};
 (action = 1) => {};
 "#;
 
+const APPLY_BRACKET_SPACING_BEFORE: &str = r#"import { Foo } from "bar";
+let foo = { a, b };
+const { a, b } = foo;
+"#;
+
+const APPLY_BRACKET_SPACING_AFTER: &str = r#"import {Foo} from "bar";
+let foo = {a, b};
+const {a, b} = foo;
+"#;
+
 // Without this, Test (windows-latest) fails with: `warning: constant `DEFAULT_CONFIGURATION_BEFORE` is never used`
 #[allow(dead_code)]
 const DEFAULT_CONFIGURATION_BEFORE: &str = r#"function f() {
@@ -649,6 +659,51 @@ fn applies_custom_arrow_parentheses() {
     ));
 }
 
+#[test]
+fn applies_custom_bracket_spacing() {
+    let mut fs = MemoryFileSystem::default();
+    let mut console = BufferConsole::default();
+
+    let file_path = Path::new("file.js");
+    fs.insert(file_path.into(), APPLY_BRACKET_SPACING_BEFORE.as_bytes());
+
+    let result = run_cli(
+        DynRef::Borrowed(&mut fs),
+        &mut console,
+        Args::from(
+            [
+                ("format"),
+                ("--bracket-spacing"),
+                ("false"),
+                ("--write"),
+                file_path.as_os_str().to_str().unwrap(),
+            ]
+            .as_slice(),
+        ),
+    );
+
+    assert!(result.is_ok(), "run_cli returned {result:?}");
+
+    let mut file = fs
+        .open(file_path)
+        .expect("formatting target file was removed by the CLI");
+
+    let mut content = String::new();
+    file.read_to_string(&mut content)
+        .expect("failed to read file from memory FS");
+
+    assert_eq!(content, APPLY_BRACKET_SPACING_AFTER);
+
+    drop(file);
+    assert_cli_snapshot(SnapshotPayload::new(
+        module_path!(),
+        "applies_custom_bracket_spacing",
+        fs,
+        console,
+        result,
+    ));
+}
+
 #[test]
 fn trailing_comma_parse_errors() {
     let mut console = BufferConsole::default();

crates/biome_cli/tests/snapshots/main_commands_check/check_help.snap

@@ -37,6 +37,8 @@ The configuration that is contained inside the file `biome.json`
                               only in for statements where it is necessary because of ASI.
         --arrow-parentheses=<always|as-needed>  Whether to add non-necessary parentheses to arrow functions.
                               Defaults to "always".
+        --bracket-spacing=<true|false>  Whether to insert spaces around brackets in object literals.
+                              Defaults to true.
         --javascript-formatter-enabled=<true|false>  Control the formatter for JavaScript (and its super
                               languages) files.
         --javascript-formatter-indent-style=<tab|space>  The indent style applied to JavaScript (and

crates/biome_cli/tests/snapshots/main_commands_ci/ci_help.snap

@@ -39,6 +39,8 @@ The configuration that is contained inside the file `biome.json`
                               only in for statements where it is necessary because of ASI.
         --arrow-parentheses=<always|as-needed>  Whether to add non-necessary parentheses to arrow functions.
                               Defaults to "always".
+        --bracket-spacing=<true|false>  Whether to insert spaces around brackets in object literals.
+                              Defaults to true.
         --javascript-formatter-enabled=<true|false>  Control the formatter for JavaScript (and its super
                               languages) files.
         --javascript-formatter-indent-style=<tab|space>  The indent style applied to JavaScript (and

crates/biome_cli/tests/snapshots/main_commands_format/applies_custom_bracket_spacing.snap

@@ -0,0 +1,20 @@
+---
+source: crates/biome_cli/tests/snap_test.rs
+expression: content
+---
+## `file.js`
+
+```js
+import {Foo} from "bar";
+let foo = {a, b};
+const {a, b} = foo;
+
+```
+
+# Emitted Messages
+
+```block
+Formatted 1 file(s) in <TIME>
+```
+
+

crates/biome_cli/tests/snapshots/main_commands_format/format_help.snap

@@ -26,6 +26,8 @@ Formatting options specific to the JavaScript files
                               only in for statements where it is necessary because of ASI.
         --arrow-parentheses=<always|as-needed>  Whether to add non-necessary parentheses to arrow functions.
                               Defaults to "always".
+        --bracket-spacing=<true|false>  Whether to insert spaces around brackets in object literals.
+                              Defaults to true.
         --javascript-formatter-enabled=<true|false>  Control the formatter for JavaScript (and its super
                               languages) files.
         --javascript-formatter-indent-style=<tab|space>  The indent style applied to JavaScript (and

crates/biome_formatter/src/builders.rs

@@ -601,6 +601,32 @@ pub const fn space() -> Space {
     Space
 }
 
+/// Optionally inserts a single space if the given condition is true.
+///
+/// # Examples
+///
+/// ```
+/// use biome_formatter::format;
+/// use biome_formatter::prelude::*;
+///
+/// # fn main() -> FormatResult<()> {
+/// let elements = format!(SimpleFormatContext::default(), [text("a"), maybe_space(true), text("b")])?;
+/// let nospace = format!(SimpleFormatContext::default(), [text("a"), maybe_space(false), text("b")])?;
+///
+/// assert_eq!("a b", elements.print()?.as_code());
+/// assert_eq!("ab", nospace.print()?.as_code());
+/// # Ok(())
+/// # }
+/// ```
+#[inline]
+pub fn maybe_space(should_insert: bool) -> Option<Space> {
+    if should_insert {
+        Some(Space)
+    } else {
+        None
+    }
+}
+
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub struct Space;
 
@@ -1047,6 +1073,110 @@ pub fn soft_block_indent<Context>(content: &impl Format<Context>) -> BlockIndent
     }
 }
 
+/// Conditionally adds spaces around the content if its enclosing group fits
+/// within a single line and the caller suggests that the space should be added.
+/// Otherwise indents the content and separates it by line breaks.
+///
+/// # Examples
+///
+/// Adds line breaks and indents the content if the enclosing group doesn't fit on the line.
+///
+/// ```
+/// use biome_formatter::{format, format_args, LineWidth, SimpleFormatOptions};
+/// use biome_formatter::prelude::*;
+///
+/// # fn main() -> FormatResult<()> {
+/// let context = SimpleFormatContext::new(SimpleFormatOptions {
+///     line_width: LineWidth::try_from(10).unwrap(),
+///     ..SimpleFormatOptions::default()
+/// });
+///
+/// let elements = format!(context, [
+///     group(&format_args![
+///         text("{"),
+///         soft_block_indent_with_maybe_space(&format_args![
+///             text("aPropertyThatExceeds"),
+///             text(":"),
+///             space(),
+///             text("'line width'"),
+///         ], false),
+///         text("}")
+///     ])
+/// ])?;
+///
+/// assert_eq!(
+///     "{\n\taPropertyThatExceeds: 'line width'\n}",
+///     elements.print()?.as_code()
+/// );
+/// # Ok(())
+/// # }
+/// ```
+///
+/// Adds spaces around the content if the caller requests it and the group fits on the line.
+///
+/// ```
+/// use biome_formatter::{format, format_args};
+/// use biome_formatter::prelude::*;
+///
+/// # fn main() -> FormatResult<()> {
+/// let elements = format!(SimpleFormatContext::default(), [
+///     group(&format_args![
+///         text("{"),
+///         soft_block_indent_with_maybe_space(&format_args![
+///             text("a"),
+///             text(":"),
+///             space(),
+///             text("5"),
+///         ], true),
+///         text("}")
+///     ])
+/// ])?;
+///
+/// assert_eq!(
+///     "{ a: 5 }",
+///     elements.print()?.as_code()
+/// );
+/// # Ok(())
+/// # }
+/// ```
+///
+/// Does not add spaces around the content if the caller denies it and the group fits on the line.
+/// ```
+/// use biome_formatter::{format, format_args};
+/// use biome_formatter::prelude::*;
+///
+/// # fn main() -> FormatResult<()> {
+/// let elements = format!(SimpleFormatContext::default(), [
+///     group(&format_args![
+///         text("{"),
+///         soft_block_indent_with_maybe_space(&format_args![
+///             text("a"),
+///             text(":"),
+///             space(),
+///             text("5"),
+///         ], false),
+///         text("}")
+///     ])
+/// ])?;
+///
+/// assert_eq!(
+///     "{a: 5}",
+///     elements.print()?.as_code()
+/// );
+/// # Ok(())
+/// # }
+/// ```
+pub fn soft_block_indent_with_maybe_space<Context>(
+    content: &impl Format<Context>,
+    should_add_space: bool,
+) -> BlockIndent<Context> {
+    if should_add_space {
+        soft_space_or_block_indent(content)
+    } else {
+        soft_block_indent(content)
+    }
+}
+
 /// If the enclosing `Group` doesn't fit on a single line, inserts a line break and indent.
 /// Otherwise, just inserts a space.
 ///

crates/biome_js_formatter/src/context.rs

@@ -162,6 +162,9 @@ pub struct JsFormatOptions {
     /// Whether to add non-necessary parentheses to arrow functions. Defaults to "always".
     arrow_parentheses: ArrowParentheses,
 
+    /// Whether to insert spaces around brackets in object literals. Defaults to true.
+    bracket_spacing: BracketSpacing,
+
     /// Information related to the current file
     source_type: JsFileSource,
 }
@@ -180,6 +183,7 @@ impl JsFormatOptions {
             trailing_comma: TrailingComma::default(),
             semicolons: Semicolons::default(),
             arrow_parentheses: ArrowParentheses::default(),
+            bracket_spacing: BracketSpacing::default(),
         }
     }
 
@@ -188,6 +192,11 @@ impl JsFormatOptions {
         self
     }
 
+    pub fn with_bracket_spacing(mut self, bracket_spacing: BracketSpacing) -> Self {
+        self.bracket_spacing = bracket_spacing;
+        self
+    }
+
     pub fn with_indent_style(mut self, indent_style: IndentStyle) -> Self {
         self.indent_style = indent_style;
         self
@@ -237,6 +246,10 @@ impl JsFormatOptions {
         self.arrow_parentheses = arrow_parentheses;
     }
 
+    pub fn set_bracket_spacing(&mut self, bracket_spacing: BracketSpacing) {
+        self.bracket_spacing = bracket_spacing;
+    }
+
     pub fn set_indent_style(&mut self, indent_style: IndentStyle) {
         self.indent_style = indent_style;
     }
@@ -277,6 +290,10 @@ impl JsFormatOptions {
         self.arrow_parentheses
     }
 
+    pub fn bracket_spacing(&self) -> BracketSpacing {
+        self.bracket_spacing
+    }
+
     pub fn quote_style(&self) -> QuoteStyle {
         self.quote_style
     }
@@ -339,7 +356,8 @@ impl fmt::Display for JsFormatOptions {
         writeln!(f, "Quote properties: {}", self.quote_properties)?;
         writeln!(f, "Trailing comma: {}", self.trailing_comma)?;
         writeln!(f, "Semicolons: {}", self.semicolons)?;
-        writeln!(f, "Arrow parentheses: {}", self.arrow_parentheses)
+        writeln!(f, "Arrow parentheses: {}", self.arrow_parentheses)?;
+        writeln!(f, "Bracket spacing: {}", self.bracket_spacing.value())
     }
 }
 
@@ -639,3 +657,30 @@ impl Deserializable for ArrowParentheses {
         }
     }
 }
+
+#[derive(Debug, Eq, PartialEq, Clone, Copy, Hash)]
+#[cfg_attr(
+    feature = "serde",
+    derive(serde::Serialize, serde::Deserialize, schemars::JsonSchema),
+    serde(rename_all = "camelCase")
+)]
+pub struct BracketSpacing(bool);
+
+impl BracketSpacing {
+    /// Return the boolean value for this [BracketSpacing]
+    pub fn value(&self) -> bool {
+        self.0
+    }
+}
+
+impl Default for BracketSpacing {
+    fn default() -> Self {
+        Self(true)
+    }
+}
+
+impl From<bool> for BracketSpacing {
+    fn from(value: bool) -> Self {
+        Self(value)
+    }
+}

crates/biome_js_formatter/src/js/module/export_named_clause.rs

@@ -1,5 +1,5 @@
 use crate::prelude::*;
-use biome_formatter::{format_args, write};
+use biome_formatter::write;
 
 use crate::utils::FormatStatementSemicolon;
 
@@ -31,12 +31,13 @@ impl FormatNodeRule<JsExportNamedClause> for FormatJsExportNamedClause {
                 [format_dangling_comments(node.syntax()).with_block_indent()]
             )?;
         } else {
+            let should_insert_space_around_brackets = f.options().bracket_spacing().value();
             write!(
                 f,
-                [group(&format_args![
-                    soft_line_indent_or_space(&specifiers.format()),
-                    soft_line_break_or_space(),
-                ])]
+                [group(&soft_block_indent_with_maybe_space(
+                    &specifiers.format(),
+                    should_insert_space_around_brackets
+                ),)]
             )?;
         }