rustfmt.toml

# =============================
# Rustfmt Best Practice (Nightly, 2025対応)
# =============================

unstable_features = true
edition = "2021"

# --- 基本 ---
max_width = 120
tab_spaces = 2
newline_style = "Unix"
indent_style = "Block"
use_small_heuristics = "Max"
blank_lines_upper_bound = 1

# --- コメントと整形 ---
normalize_comments = true
wrap_comments = true
format_code_in_doc_comments = true
comment_width = 100

# --- 波括弧スタイル ---
brace_style = "PreferSameLine"
control_brace_style = "AlwaysSameLine"

# --- インポート整形 ---
reorder_imports = true
imports_granularity = "Crate"
group_imports = "StdExternalCrate"
imports_indent = "Block"
imports_layout = "Mixed"

# --- impl / mod 整形（nightly限定）---
reorder_impl_items = true
reorder_modules = true

# --- 関数・式整形 ---
combine_control_expr = false
fn_params_layout = "Tall"          # ← 新しい正しいキー名
match_block_trailing_comma = true
match_arm_leading_pipes = "Always"

# --- 可読性・diff安定性 ---
where_single_line = false
struct_field_align_threshold = 20
enum_discrim_align_threshold = 20
space_after_colon = true
space_before_colon = false
spaces_around_ranges = false
trailing_comma = "Vertical"
trailing_semicolon = true

# --- 実験的 ---
overflow_delimited_expr = true