feature: sort inline tables (#671)

* order keys in inline tables

* add tests for sort keys in inline tables

* refactor vec deque instantiation

* use reorder arrays key

* remove unnecessary VecDeque init

* add reorder_inline_tables flag

* add reorderInlineTables to even-better-toml

* add reorder_inline_tables to formatter options config doc

* reinstate reorder arrays test case

crates/taplo/src/formatter/mod.rs

@@ -8,10 +8,12 @@ use crate::{
     syntax::{SyntaxElement, SyntaxKind::*, SyntaxNode, SyntaxToken},
     util::overlaps,
 };
+use itertools::Itertools;
 use once_cell::unsync::OnceCell;
 use rowan::{GreenNode, NodeOrToken, TextRange};
 use std::{
     cmp,
+    collections::VecDeque,
     iter::{repeat, FromIterator},
     ops::Range,
     rc::Rc,
@@ -109,6 +111,9 @@ create_options!(
         /// Alphabetically reorder array values that are not separated by blank lines.
         pub reorder_arrays: bool,
 
+        /// Alphabetically reorder inline table values.
+        pub reorder_inline_tables: bool,
+
         /// The maximum amount of consecutive blank lines allowed.
         pub allowed_blank_lines: usize,
 
@@ -166,6 +171,7 @@ impl Default for Options {
             indent_string: "  ".into(),
             reorder_keys: false,
             reorder_arrays: false,
+            reorder_inline_tables: false,
             crlf: false,
         }
     }
@@ -866,6 +872,16 @@ fn format_inline_table(
         formatted = "{}".into();
     }
 
+    let mut sorted_children = if options.reorder_inline_tables {
+        Some(
+            node.children()
+                .sorted_unstable_by(|x, y| x.to_string().cmp(&y.to_string()))
+                .collect::<VecDeque<_>>(),
+        )
+    } else {
+        None
+    };
+
     let mut node_index = 0;
     for c in node.children_with_tokens() {
         match c {
@@ -874,7 +890,16 @@ fn format_inline_table(
                     formatted += ", ";
                 }
 
-                let entry = format_entry(n, options, context);
+                let child = if options.reorder_inline_tables {
+                    sorted_children
+                        .as_mut()
+                        .and_then(|children| children.pop_front())
+                        .unwrap_or(n)
+                } else {
+                    n
+                };
+
+                let entry = format_entry(child, options, context);
                 debug_assert!(entry.comment.is_none());
                 entry.write_to(&mut formatted, options);
 
@@ -915,7 +940,6 @@ fn format_inline_table(
 
     (node.into(), formatted, comment)
 }
-
 // Check whether the array spans multiple lines in its current form.
 fn is_array_multiline(node: &SyntaxNode) -> bool {
     node.descendants_with_tokens().any(|n| n.kind() == NEWLINE)

crates/taplo/src/tests/formatter.rs

@@ -973,6 +973,34 @@ very_long_inline_table = { array = ["aaaaa", "aaaaa", "aaaaa", "aaaaa", "aaaaa",
     assert_format!(src, &formatted);
 }
 
+#[test]
+fn test_sorted_inline_tables() {
+    let src = r#"
+foo = { b = 2, a = 1 }
+
+bar = [
+  { a = 1, b = 2, c = 3 },
+  { b = 2, a = 1, d = 4, e = 5 },
+]
+"#;
+
+    let expected = r#"
+foo = { a = 1, b = 2 }
+
+bar = [{ a = 1, b = 2, c = 3 }, { a = 1, b = 2, d = 4, e = 5 }]
+"#;
+
+    let formatted = crate::formatter::format(
+        src,
+        formatter::Options {
+            reorder_inline_tables: true,
+            ..Default::default()
+        },
+    );
+
+    assert_format!(expected, &formatted);
+}
+
 #[test]
 fn test_sorted_groupings_in_array() {
     let src = r#"

editors/vscode/package.json

@@ -371,6 +371,12 @@
           "default": null,
           "description": "Alphabetically reorder array values that are not separated by blank lines."
         },
+        "evenBetterToml.formatter.reorderInlineTables": {
+          "scope": "resource",
+          "type": "boolean",
+          "default": null,
+          "description": "Alphabetically reorder inline tables."
+        },
         "evenBetterToml.formatter.allowedBlankLines": {
           "scope": "resource",
           "type": "number",

site/site/configuration/formatter-options.md

@@ -28,5 +28,6 @@ In some environments (e.g., Visual Studio Code), one needs to reload the extensi
 |   trailing_newline    |                                              Add trailing newline to the source.                                               |      true      |
 |     reorder_keys      |                               Alphabetically reorder keys that are not separated by blank lines.                               |     false      |
 |    reorder_arrays     |                           Alphabetically reorder array values that are not separated by blank lines.                           |     false      |
+| reorder_inline_tables |                                             Alphabetically reorder inline tables.                                              |     false      |
 |  allowed_blank_lines  |                                     The maximum amount of consecutive blank lines allowed.                                     |       2        |
 |         crlf          |                                                     Use CRLF line endings.                                                     |     false      |