feat: add config for forced multiline named imports/exports (#473)

Author: jakebailey

deployment/schema.json

@@ -264,6 +264,18 @@
         "description": ""
       }]
     },
+    "forceMultiLineSpecifiers": {
+      "description": "If code import/export specifiers should be forced to be on multiple lines.",
+      "type": "boolean",
+      "default": false,
+      "oneOf": [{
+        "const": true,
+        "description": ""
+      }, {
+        "const": false,
+        "description": ""
+      }]
+    },
     "sortOrder": {
       "description": "The kind of sort ordering to use.",
       "type": "string",
@@ -1273,6 +1285,12 @@
     },
     "importDeclaration.forceSingleLine": {
       "$ref": "#/definitions/forceSingleLine"
+    },
+    "exportDeclaration.forceMultiLine": {
+      "$ref": "#/definitions/forceMultiLineSpecifiers"
+    },
+    "importDeclaration.forceMultiLine": {
+      "$ref": "#/definitions/forceMultiLineSpecifiers"
     }
   }
 }

src/configuration/builder.rs

@@ -757,6 +757,16 @@ impl ConfigurationBuilder {
     self.insert("importDeclaration.forceSingleLine", value.into())
   }
 
+  /* force multi line specifiers */
+
+  pub fn export_declaration_force_multi_line(&mut self, value: bool) -> &mut Self {
+    self.insert("exportDeclaration.forceMultiLine", value.into())
+  }
+
+  pub fn import_declaration_force_multi_line(&mut self, value: bool) -> &mut Self {
+    self.insert("importDeclaration.forceMultiLine", value.into())
+  }
+
   /* member spacing */
 
   pub fn enum_declaration_member_spacing(&mut self, value: MemberSpacing) -> &mut Self {
@@ -1201,6 +1211,9 @@ mod tests {
       /* force single line */
       .export_declaration_force_single_line(true)
       .import_declaration_force_single_line(true)
+      /* force multi line specifiers */
+      .export_declaration_force_multi_line(true)
+      .import_declaration_force_multi_line(true)
       /* space settings */
       .binary_expression_space_surrounding_bitwise_and_arithmetic_operator(true)
       .comment_line_force_space_after_slashes(false)
@@ -1246,7 +1259,7 @@ mod tests {
       .while_statement_space_around(true);
 
     let inner_config = config.get_inner_config();
-    assert_eq!(inner_config.len(), 175);
+    assert_eq!(inner_config.len(), 177);
     let diagnostics = resolve_config(inner_config, &resolve_global_config(ConfigKeyMap::new(), &Default::default()).config).diagnostics;
     assert_eq!(diagnostics.len(), 0);
   }

src/configuration/resolve_config.rs

@@ -252,6 +252,9 @@ pub fn resolve_config(config: ConfigKeyMap, global_config: &GlobalConfiguration)
     /* force single line */
     import_declaration_force_single_line: get_value(&mut config, "importDeclaration.forceSingleLine", false, &mut diagnostics),
     export_declaration_force_single_line: get_value(&mut config, "exportDeclaration.forceSingleLine", false, &mut diagnostics),
+    /* force multi line specifiers */
+    import_declaration_force_multi_line: get_value(&mut config, "importDeclaration.forceMultiLine", false, &mut diagnostics),
+    export_declaration_force_multi_line: get_value(&mut config, "exportDeclaration.forceMultiLine", false, &mut diagnostics),
     /* space settings */
     binary_expression_space_surrounding_bitwise_and_arithmetic_operator: get_value(
       &mut config,

src/configuration/types.rs

@@ -523,6 +523,11 @@ pub struct Configuration {
   pub import_declaration_force_single_line: bool,
   #[serde(rename = "exportDeclaration.forceSingleLine")]
   pub export_declaration_force_single_line: bool,
+  /* force multi line specifiers */
+  #[serde(rename = "exportDeclaration.forceMultiLine")]
+  pub export_declaration_force_multi_line: bool,
+  #[serde(rename = "importDeclaration.forceMultiLine")]
+  pub import_declaration_force_multi_line: bool,
 
   /* use space separator */
   #[serde(rename = "binaryExpression.spaceSurroundingBitwiseAndArithmeticOperator")]

src/generation/generate.rs

@@ -992,7 +992,7 @@ fn gen_export_named_decl<'a>(node: &'a NamedExport, context: &mut Context<'a>) -
   let should_single_line = force_single_line
     || (default_export.is_none()
       && namespace_export.is_none()
-      && named_exports.len() <= 1
+      && (named_exports.len() <= 1 && !context.config.export_declaration_force_multi_line)
       && node.start_line_fast(context.program) == node.end_line_fast(context.program));
 
   // generate
@@ -1011,6 +1011,7 @@ fn gen_export_named_decl<'a>(node: &'a NamedExport, context: &mut Context<'a>) -
         parent: node.into(),
         specifiers: named_exports.into_iter().map(|x| x.into()).collect(),
         force_single_line,
+        force_multi_line_specifiers: context.config.export_declaration_force_multi_line,
       },
       context,
     ));
@@ -1177,7 +1178,7 @@ fn gen_import_decl<'a>(node: &'a ImportDecl, context: &mut Context<'a>) -> Print
   let should_single_line = force_single_line
     || (default_import.is_none()
       && namespace_import.is_none()
-      && named_imports.len() <= 1
+      && (named_imports.len() <= 1 && !context.config.import_declaration_force_multi_line)
       && node.start_line_fast(context.program) == node.end_line_fast(context.program));
   let has_named_imports = !named_imports.is_empty() || {
     let from_keyword = context.token_finder.get_previous_token_if_from_keyword(node.src);
@@ -1211,6 +1212,7 @@ fn gen_import_decl<'a>(node: &'a ImportDecl, context: &mut Context<'a>) -> Print
         parent: node.into(),
         specifiers: named_imports.into_iter().map(|x| x.into()).collect(),
         force_single_line,
+        force_multi_line_specifiers: context.config.import_declaration_force_multi_line,
       },
       context,
     ));
@@ -1395,6 +1397,7 @@ struct GenNamedImportOrExportSpecifierOptions<'a> {
   parent: Node<'a>,
   specifiers: Vec<Node<'a>>,
   force_single_line: bool,
+  force_multi_line_specifiers: bool,
 }
 
 fn gen_named_import_or_export_specifiers<'a>(opts: GenNamedImportOrExportSpecifierOptions<'a>, context: &mut Context<'a>) -> PrintItems {
@@ -1406,6 +1409,7 @@ fn gen_named_import_or_export_specifiers<'a>(opts: GenNamedImportOrExportSpecifi
       prefer_hanging: get_prefer_hanging(opts.parent, context),
       prefer_single_line: get_prefer_single_line(opts.parent, context),
       force_single_line: opts.force_single_line,
+      force_multi_line: opts.force_multi_line_specifiers,
       surround_single_line_with_spaces: get_use_space(opts.parent, context),
       allow_blank_lines: false,
       node_sorter: get_node_sorter(opts.parent, context),
@@ -2630,6 +2634,7 @@ fn gen_object_lit<'a>(node: &'a ObjectLit, context: &mut Context<'a>) -> PrintIt
       prefer_hanging: context.config.object_expression_prefer_hanging,
       prefer_single_line: context.config.object_expression_prefer_single_line,
       force_single_line: false,
+      force_multi_line: false,
       surround_single_line_with_spaces: context.config.object_expression_space_surrounding_properties,
       allow_blank_lines: true,
       node_sorter: None,
@@ -3359,6 +3364,7 @@ fn gen_type_lit<'a>(node: &'a TsTypeLit, context: &mut Context<'a>) -> PrintItem
       prefer_hanging: context.config.type_literal_prefer_hanging,
       prefer_single_line: context.config.type_literal_prefer_single_line,
       force_single_line: false,
+      force_multi_line: false,
       surround_single_line_with_spaces: context.config.type_literal_space_surrounding_properties,
       allow_blank_lines: true,
       node_sorter: None,
@@ -4073,6 +4079,7 @@ fn gen_object_pat<'a>(node: &'a ObjectPat, context: &mut Context<'a>) -> PrintIt
       prefer_hanging: context.config.object_pattern_prefer_hanging,
       prefer_single_line: context.config.object_pattern_prefer_single_line,
       force_single_line: false,
+      force_multi_line: false,
       surround_single_line_with_spaces: context.config.object_pattern_space_surrounding_properties,
       allow_blank_lines: true,
       node_sorter: None,
@@ -7675,6 +7682,7 @@ struct GenObjectLikeNodeOptions<'a> {
   prefer_hanging: bool,
   prefer_single_line: bool,
   force_single_line: bool,
+  force_multi_line: bool,
   surround_single_line_with_spaces: bool,
   allow_blank_lines: bool,
   node_sorter: Option<Box<dyn Fn((usize, Option<Node<'a>>), (usize, Option<Node<'a>>), &Program<'a>) -> std::cmp::Ordering>>,
@@ -7686,7 +7694,8 @@ fn gen_object_like_node<'a>(opts: GenObjectLikeNodeOptions<'a>, context: &mut Co
   let child_tokens = get_tokens_from_children_with_tokens(opts.node, context.program);
   let open_brace_token = child_tokens.iter().find(|t| t.token == Token::LBrace);
   let close_brace_token = child_tokens.iter().rev().find(|t| t.token == Token::RBrace);
-  let force_multi_line = !opts.force_single_line && get_use_new_lines_for_nodes_with_preceeding_token("{", &opts.members, opts.prefer_single_line, context);
+  let force_multi_line =
+    opts.force_multi_line || !opts.force_single_line && get_use_new_lines_for_nodes_with_preceeding_token("{", &opts.members, opts.prefer_single_line, context);
 
   let first_member_range = opts.members.get(0).map(|x| x.range());
   let obj_range = if let (Some(open_brace_token), Some(close_brace_token)) = (open_brace_token, close_brace_token) {

tests/specs/declarations/export/ExportDeclaration_ForceMultiLine_True.txt

@@ -0,0 +1,81 @@
+~~ exportDeclaration.forceMultiLine: true, lineWidth: 40 ~~
+== should always add a new line between exports ==
+export { testing, a, b, c, d, e } from "./test.ts";
+export { testing, a, b, c, d, e // test
+} from "./test.ts";
+export { a, b, c, d, e /* this is ok though testing testing */ } from "./test.ts";
+export { a, b, c, d, e /* and
+not ok */ } from "./test.ts";
+
+[expect]
+export {
+    a,
+    b,
+    c,
+    d,
+    e,
+    testing,
+} from "./test.ts";
+export {
+    a,
+    b,
+    c,
+    d,
+    e, // test
+    testing,
+} from "./test.ts";
+export {
+    a,
+    b,
+    c,
+    d,
+    e, /* this is ok though testing testing */
+} from "./test.ts";
+export {
+    a,
+    b,
+    c,
+    d,
+    e, /* and
+not ok */
+} from "./test.ts";
+
+== should not collapse a multi-line one ==
+export {
+
+  a,
+
+  b,
+  c,
+  /* testing */
+  d,
+} from "./test.ts";
+export {
+  a,
+  b,
+  c,
+  d,
+} from "./test.ts";
+
+[expect]
+export {
+    a,
+    b,
+    c,
+    /* testing */
+    d,
+} from "./test.ts";
+export {
+    a,
+    b,
+    c,
+    d,
+} from "./test.ts";
+
+== should make a single export multi-line ==
+export { a } from "./test.ts";
+
+[expect]
+export {
+    a,
+} from "./test.ts";

tests/specs/declarations/import/ImportDeclaration_ForceMultiLine.txt

@@ -0,0 +1,91 @@
+~~ importDeclaration.forceMultiLine: true, lineWidth: 40 ~~
+== should always add a new line between ==
+import { testing, a, b, c, d, e } from "./test.ts";
+import { testing, a, b, c, d, e // test
+} from "./test.ts";
+import { a, b, c, d, e /* this is ok though testing testing */ } from "./test.ts";
+import { a, b, c, d, e /* and
+not ok */ } from "./test.ts";
+
+[expect]
+import {
+    a,
+    b,
+    c,
+    d,
+    e,
+    testing,
+} from "./test.ts";
+import {
+    a,
+    b,
+    c,
+    d,
+    e, // test
+    testing,
+} from "./test.ts";
+import {
+    a,
+    b,
+    c,
+    d,
+    e, /* this is ok though testing testing */
+} from "./test.ts";
+import {
+    a,
+    b,
+    c,
+    d,
+    e, /* and
+not ok */
+} from "./test.ts";
+
+== should collapse a multi-line one ==
+import { /* a */
+
+  a,
+
+  /* test */ b, /* other */
+  c,
+  /* testing */
+  d,
+} from "./test.ts"; // actually, a block comment at the start of this line causes a bug
+// where the block comment will not have a space after it. Not worth fixing though
+// because it will be fixed by formatting again (which the CLI does automatically)
+// and it's super rare that someone would put a comment there.
+import {
+  /* a */
+  a,
+  b,
+  c,
+  d,
+} from "./test.ts";
+
+[expect]
+import {
+    /* a */
+
+    a,
+    /* test */ b, /* other */
+    c,
+    /* testing */
+    d,
+} from "./test.ts"; // actually, a block comment at the start of this line causes a bug
+// where the block comment will not have a space after it. Not worth fixing though
+// because it will be fixed by formatting again (which the CLI does automatically)
+// and it's super rare that someone would put a comment there.
+import {
+    /* a */
+    a,
+    b,
+    c,
+    d,
+} from "./test.ts";
+
+== should make a single import multi-line ==
+import { a } from "./test.ts";
+
+[expect]
+import {
+    a,
+} from "./test.ts";