feat: struct initializer lint (#11892)

Author: onbjerg

crates/lint/src/sol/info/mod.rs

@@ -12,6 +12,9 @@ use screaming_snake_case::{SCREAMING_SNAKE_CASE_CONSTANT, SCREAMING_SNAKE_CASE_I
 mod imports;
 use imports::{UNALIASED_PLAIN_IMPORT, UNUSED_IMPORT};
 
+mod named_struct_fields;
+use named_struct_fields::NAMED_STRUCT_FIELDS;
+
 mod unsafe_cheatcodes;
 use unsafe_cheatcodes::UNSAFE_CHEATCODE_USAGE;
 
@@ -21,5 +24,6 @@ register_lints!(
     (MixedCaseFunction, early, (MIXED_CASE_FUNCTION)),
     (ScreamingSnakeCase, early, (SCREAMING_SNAKE_CASE_CONSTANT, SCREAMING_SNAKE_CASE_IMMUTABLE)),
     (Imports, early, (UNALIASED_PLAIN_IMPORT, UNUSED_IMPORT)),
+    (NamedStructFields, late, (NAMED_STRUCT_FIELDS)),
     (UnsafeCheatcodes, early, (UNSAFE_CHEATCODE_USAGE))
 );

crates/lint/src/sol/info/named_struct_fields.rs

@@ -0,0 +1,31 @@
+use solar::sema::hir::{CallArgs, CallArgsKind, Expr, ExprKind, ItemId, Res};
+
+use crate::{
+    linter::{LateLintPass, LintContext},
+    sol::{Severity, SolLint, info::NamedStructFields},
+};
+
+declare_forge_lint!(
+    NAMED_STRUCT_FIELDS,
+    Severity::Info,
+    "named-struct-fields",
+    "prefer initializing structs with named fields"
+);
+
+impl<'hir> LateLintPass<'hir> for NamedStructFields {
+    fn check_expr(
+        &mut self,
+        ctx: &LintContext,
+        _hir: &'hir solar::sema::hir::Hir<'hir>,
+        expr: &'hir solar::sema::hir::Expr<'hir>,
+    ) {
+        if let ExprKind::Call(
+            Expr { kind: ExprKind::Ident([Res::Item(ItemId::Struct(_struct_id))]), .. },
+            CallArgs { kind: CallArgsKind::Unnamed(_args), .. },
+            _,
+        ) = &expr.kind
+        {
+            ctx.emit(&NAMED_STRUCT_FIELDS, expr.span);
+        }
+    }
+}

crates/lint/testdata/NamedStructFields.sol

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.18;
+
+contract NamedStructFields {
+    struct Person {
+        string name;
+        uint256 age;
+        address wallet;
+    }
+
+    function namedArgs() public {
+        Person memory person = Person({
+            name: "Alice",
+            age: 25,
+            wallet: address(0)
+        });
+    }
+
+    function positionalArgs() public {
+        Person memory person = Person("Alice", 25, address(0)); //~NOTE: prefer initializing structs with named fields
+    }
+}

crates/lint/testdata/NamedStructFields.stderr

@@ -0,0 +1,8 @@
+note[named-struct-fields]: prefer initializing structs with named fields
+  --> ROOT/testdata/NamedStructFields.sol:LL:CC
+   |
+LL |         Person memory person = Person("Alice", 25, address(0));
+   |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: https://book.getfoundry.sh/reference/forge/forge-lint#named-struct-fields
+