feat(rome_js_formatter): type alias as assignment like

crates/rome_js_formatter/src/js/expressions/object_expression.rs

@@ -1,47 +1,13 @@
 use crate::prelude::*;
-use crate::utils::node_has_leading_newline;
-
+use crate::utils::JsObjectLike;
 use rome_formatter::write;
 use rome_js_syntax::JsObjectExpression;
-use rome_js_syntax::JsObjectExpressionFields;
 
 #[derive(Debug, Clone, Default)]
 pub struct FormatJsObjectExpression;
 
 impl FormatNodeRule<JsObjectExpression> for FormatJsObjectExpression {
     fn fmt_fields(&self, node: &JsObjectExpression, f: &mut JsFormatter) -> FormatResult<()> {
-        let JsObjectExpressionFields {
-            l_curly_token,
-            members,
-            r_curly_token,
-        } = node.as_fields();
-
-        let has_newline = node_has_leading_newline(members.syntax());
-
-        if members.is_empty() {
-            write!(
-                f,
-                [
-                    format_delimited(&l_curly_token?, &members.format(), &r_curly_token?)
-                        .soft_block_indent()
-                ]
-            )
-        } else if has_newline {
-            write!(
-                f,
-                [
-                    format_delimited(&l_curly_token?, &members.format(), &r_curly_token?)
-                        .block_indent()
-                ]
-            )
-        } else {
-            write!(
-                f,
-                [
-                    format_delimited(&l_curly_token?, &members.format(), &r_curly_token?)
-                        .soft_block_spaces()
-                ]
-            )
-        }
+        write!(f, [JsObjectLike::from(node.clone())])
     }
 }

crates/rome_js_formatter/src/lib.rs

@@ -457,10 +457,15 @@ mod test {
     // use this test check if your snippet prints as you wish, without using a snapshot
     fn quick_test() {
         let src = r#"
+export type a =
+  // foo
+  | foo1 & foo2
+  // bar
+  | bar1 & bar2
+  // prettier-ignore
+  | qux1 & qux2;
+
 
-it(`does something really long and complicated so I have to write a very long name for the test`, function () {
-  console.log("hello!");
- });
 
         "#;
         let syntax = SourceType::tsx();

crates/rome_js_formatter/src/ts/declarations/type_alias_declaration.rs

@@ -1,37 +1,25 @@
 use crate::prelude::*;
-use crate::utils::FormatWithSemicolon;
-
+use crate::utils::{FormatWithSemicolon, JsAnyAssignmentLike};
 use rome_formatter::{format_args, write};
-use rome_js_syntax::{TsTypeAliasDeclaration, TsTypeAliasDeclarationFields};
+use rome_js_syntax::TsTypeAliasDeclaration;
 
 #[derive(Debug, Clone, Default)]
 pub struct FormatTsTypeAliasDeclaration;
 
 impl FormatNodeRule<TsTypeAliasDeclaration> for FormatTsTypeAliasDeclaration {
     fn fmt_fields(&self, node: &TsTypeAliasDeclaration, f: &mut JsFormatter) -> FormatResult<()> {
-        let TsTypeAliasDeclarationFields {
-            type_token,
-            binding_identifier,
-            type_parameters,
-            eq_token,
-            ty,
-            semicolon_token,
-        } = node.as_fields();
-
+        let type_token = node.type_token()?;
+        let semicolon = node.semicolon_token();
+        let assignment_like = format_with(|f| write!(f, [JsAnyAssignmentLike::from(node.clone())]));
         write!(
             f,
             [FormatWithSemicolon::new(
-                &format_args!(
+                &format_args![
                     type_token.format(),
                     space_token(),
-                    binding_identifier.format(),
-                    type_parameters.format(),
-                    space_token(),
-                    eq_token.format(),
-                    space_token(),
-                    ty.format(),
-                ),
-                semicolon_token.as_ref()
+                    group_elements(&assignment_like)
+                ],
+                semicolon.as_ref()
             )]
         )
     }

crates/rome_js_formatter/src/ts/types/object_type.rs

@@ -1,36 +1,13 @@
 use crate::prelude::*;
-use crate::utils::node_has_leading_newline;
-
+use crate::utils::JsObjectLike;
 use rome_formatter::write;
-use rome_js_syntax::{TsObjectType, TsObjectTypeFields};
+use rome_js_syntax::TsObjectType;
 
 #[derive(Debug, Clone, Default)]
 pub struct FormatTsObjectType;
 
 impl FormatNodeRule<TsObjectType> for FormatTsObjectType {
     fn fmt_fields(&self, node: &TsObjectType, f: &mut JsFormatter) -> FormatResult<()> {
-        let TsObjectTypeFields {
-            l_curly_token,
-            members,
-            r_curly_token,
-        } = node.as_fields();
-
-        if node_has_leading_newline(members.syntax()) {
-            write!(
-                f,
-                [
-                    format_delimited(&l_curly_token?, &members.format(), &r_curly_token?)
-                        .block_indent()
-                ]
-            )
-        } else {
-            write!(
-                f,
-                [
-                    format_delimited(&l_curly_token?, &members.format(), &r_curly_token?,)
-                        .soft_block_spaces()
-                ]
-            )
-        }
+        write!(f, [JsObjectLike::from(node.clone())])
     }
 }

crates/rome_js_formatter/src/ts/types/union_type.rs

@@ -17,14 +17,14 @@ impl FormatNodeRule<TsUnionType> for FormatTsUnionType {
 
         write![
             f,
-            [group_elements(&indent(&format_args![
+            [group_elements(&format_args![
                 soft_line_break(),
                 FormatTypeSetLeadingSeparator {
                     separator: JsSyntaxKind::PIPE,
                     leading_separator: leading_separator_token.as_ref()
                 },
                 types.format()
-            ]))]
+            ])]
         ]
     }
 }

crates/rome_js_formatter/src/utils/assignment_like.rs

@@ -7,7 +7,8 @@ use rome_js_syntax::{
     JsAnyObjectAssignmentPatternMember, JsAnyObjectBindingPatternMember, JsAnyObjectMemberName,
     JsAssignmentExpression, JsInitializerClause, JsObjectAssignmentPattern,
     JsObjectAssignmentPatternProperty, JsObjectBindingPattern, JsPropertyObjectMember,
-    JsSyntaxKind, JsVariableDeclarator, TsAnyVariableAnnotation, TsType,
+    JsSyntaxKind, JsVariableDeclarator, TsAnyVariableAnnotation, TsIdentifierBinding, TsType,
+    TsTypeAliasDeclaration,
 };
 use rome_js_syntax::{JsAnyLiteralExpression, JsSyntaxNode};
 use rome_rowan::{declare_node_union, AstNode, SyntaxResult};
@@ -17,15 +18,16 @@ declare_node_union! {
         JsPropertyObjectMember |
         JsAssignmentExpression |
         JsObjectAssignmentPatternProperty |
-        JsVariableDeclarator
+        JsVariableDeclarator |
+        TsTypeAliasDeclaration
 }
 
 declare_node_union! {
-    pub(crate) LeftAssignmentLike = JsAnyAssignmentPattern | JsAnyObjectMemberName | JsAnyBindingPattern
+    pub(crate) LeftAssignmentLike = JsAnyAssignmentPattern | JsAnyObjectMemberName | JsAnyBindingPattern | TsIdentifierBinding
 }
 
 declare_node_union! {
-    pub(crate) RightAssignmentLike = JsAnyExpression | JsAnyAssignmentPattern | JsInitializerClause
+    pub(crate) RightAssignmentLike = JsAnyExpression | JsAnyAssignmentPattern | JsInitializerClause | TsType
 }
 
 declare_node_union! {
@@ -151,6 +153,8 @@ impl RightAssignmentLike {
             RightAssignmentLike::JsAnyExpression(expression) => Some(expression.clone()),
             RightAssignmentLike::JsInitializerClause(initializer) => initializer.expression().ok(),
             RightAssignmentLike::JsAnyAssignmentPattern(_) => None,
+            // TODO: check here
+            RightAssignmentLike::TsType(_) => None,
         }
     }
 }
@@ -167,6 +171,9 @@ impl Format<JsFormatContext> for RightAssignmentLike {
             RightAssignmentLike::JsInitializerClause(initializer) => {
                 write!(f, [space_token(), initializer.format()])
             }
+            RightAssignmentLike::TsType(ty) => {
+                write!(f, [space_token(), ty.format()])
+            }
         }
     }
 }
@@ -294,6 +301,9 @@ impl JsAnyAssignmentLike {
                 // SAFETY: Calling `unwrap` here is safe because we check `should_only_left` variant at the beginning of the `layout` function
                 Ok(variable_declarator.initializer().unwrap().into())
             }
+            JsAnyAssignmentLike::TsTypeAliasDeclaration(type_alias_declaration) => {
+                Ok(type_alias_declaration.ty()?.into())
+            }
         }
     }
 
@@ -309,6 +319,9 @@ impl JsAnyAssignmentLike {
             JsAnyAssignmentLike::JsVariableDeclarator(variable_declarator) => {
                 Ok(variable_declarator.id()?.into())
             }
+            JsAnyAssignmentLike::TsTypeAliasDeclaration(type_alias_declaration) => {
+                Ok(type_alias_declaration.binding_identifier()?.into())
+            }
         }
     }
 
@@ -347,9 +360,20 @@ impl JsAnyAssignmentLike {
             JsAnyAssignmentLike::JsVariableDeclarator(variable_declarator) => {
                 let id = variable_declarator.id()?;
                 let variable_annotation = variable_declarator.variable_annotation();
+
                 write!(f, [id.format(), variable_annotation.format()])?;
                 Ok(false)
             }
+            JsAnyAssignmentLike::TsTypeAliasDeclaration(type_alias_declaration) => {
+                let binding_identifier = type_alias_declaration.binding_identifier()?;
+                let type_parameters = type_alias_declaration.type_parameters();
+
+                write!(f, [binding_identifier.format()])?;
+                if let Some(type_parameters) = type_parameters {
+                    write!(f, [type_parameters.format(),])?;
+                }
+                Ok(false)
+            }
         }
     }
 
@@ -374,6 +398,10 @@ impl JsAnyAssignmentLike {
                 }
                 Ok(())
             }
+            JsAnyAssignmentLike::TsTypeAliasDeclaration(type_alias_declaration) => {
+                let eq_token = type_alias_declaration.eq_token()?;
+                write!(f, [space_token(), eq_token.format()])
+            }
         }
     }
 
@@ -403,6 +431,10 @@ impl JsAnyAssignmentLike {
                 }
                 Ok(())
             }
+            JsAnyAssignmentLike::TsTypeAliasDeclaration(type_alias_declaration) => {
+                let ty = type_alias_declaration.ty()?;
+                write!(f, [space_token(), ty.format()])
+            }
         }
     }
 
@@ -423,10 +455,8 @@ impl JsAnyAssignmentLike {
             return Ok(AssignmentLikeLayout::BreakLeftHandSide);
         }
 
-        if let Some(expression) = &right {
-            if should_break_after_operator(expression)? {
-                return Ok(AssignmentLikeLayout::BreakAfterOperator);
-            }
+        if self.should_break_after_operator()? {
+            return Ok(AssignmentLikeLayout::BreakAfterOperator);
         }
 
         if is_left_short {
@@ -559,6 +589,35 @@ impl JsAnyAssignmentLike {
         Ok(false)
     }
 
+    fn is_complex_type_alias(&self) -> SyntaxResult<bool> {
+        let result = if let JsAnyAssignmentLike::TsTypeAliasDeclaration(type_alias_declaration) =
+            self
+        {
+            let type_parameters = type_alias_declaration.type_parameters();
+
+            if let Some(type_parameters) = type_parameters {
+                let items = type_parameters.items();
+                if items.len() <= 1 {
+                    return Ok(false);
+                };
+                for type_parameter in type_parameters.items() {
+                    let type_parameter = type_parameter?;
+
+                    if type_parameter.constraint().is_some() || type_parameter.default().is_some() {
+                        return Ok(true);
+                    }
+                }
+                return Ok(false);
+            } else {
+                false
+            }
+        } else {
+            false
+        };
+
+        Ok(result)
+    }
+
     /// Particular function that checks if the left hand side of a [JsAnyAssignmentLike] should
     /// be broken on multiple lines
     fn should_break_left_hand_side(&self) -> SyntaxResult<bool> {
@@ -573,7 +632,25 @@ impl JsAnyAssignmentLike {
             .and_then(|annotation| is_complex_type_annotation(annotation).ok())
             .unwrap_or(false);
 
-        Ok(is_complex_destructuring || has_complex_type_annotation)
+        let is_complex_type_alias = self.is_complex_type_alias()?;
+
+        Ok(is_complex_destructuring || has_complex_type_annotation || is_complex_type_alias)
+    }
+
+    /// Checks if the the current assignment is eligible for [AssignmentLikeLayout::BreakAfterOperator]
+    ///
+    /// This function is small wrapper around [should_break_after_operator] because it has to work
+    /// for nodes that belong to TypeScript too.
+    fn should_break_after_operator(&self) -> SyntaxResult<bool> {
+        let right = self.right()?;
+
+        let result = if let Some(expression) = right.as_expression() {
+            should_break_after_operator(&expression)?
+        } else {
+            has_new_line_before_comment(right.syntax())
+        };
+
+        Ok(result)
     }
 }
 

crates/rome_js_formatter/src/utils/mod.rs

@@ -9,6 +9,7 @@ pub(crate) mod format_class;
 pub mod jsx_utils;
 mod member_chain;
 mod object;
+mod object_like;
 mod object_pattern_like;
 #[cfg(test)]
 mod quickcheck_utils;
@@ -18,6 +19,7 @@ pub(crate) use assignment_like::{should_break_after_operator, JsAnyAssignmentLik
 pub(crate) use binary_like_expression::{format_binary_like_expression, JsAnyBinaryLikeExpression};
 pub(crate) use format_conditional::{format_conditional, Conditional};
 pub(crate) use member_chain::format_call_expression;
+pub(crate) use object_like::JsObjectLike;
 pub(crate) use object_pattern_like::JsObjectPatternLike;
 use rome_formatter::{format_args, normalize_newlines, write, Buffer, VecBuffer};
 use rome_js_syntax::suppression::{has_suppressions_category, SuppressionCategory};