Rustup to ea0dc92 II

Author: mcarton

clippy_lints/src/collapsible_if.rs

@@ -72,8 +72,8 @@ fn check_if(cx: &EarlyContext, expr: &ast::Expr) {
 fn check_collapsible_maybe_if_let(cx: &EarlyContext, else_: &ast::Expr) {
     if_let_chain! {[
         let ast::ExprKind::Block(ref block) = else_.node,
-        block.stmts.is_empty(),
-        let Some(ref else_) = block.expr,
+        let Some(ref else_) = expr_block(block),
+        !in_macro(cx, else_.span),
     ], {
         match else_.node {
             ast::ExprKind::If(..) | ast::ExprKind::IfLet(..) => {
@@ -96,7 +96,7 @@ fn check_collapsible_no_if_let(
     then: &ast::Block,
 ) {
     if_let_chain! {[
-        let Some(inner) = single_stmt_of_block(then),
+        let Some(inner) = expr_block(then),
         let ast::ExprKind::If(ref check_inner, ref content, None) = inner.node,
     ], {
         if expr.span.expn_id != inner.span.expn_id {
@@ -128,28 +128,16 @@ fn check_to_string(cx: &EarlyContext, e: &ast::Expr) -> Cow<'static, str> {
     }
 }
 
-fn single_stmt_of_block(block: &ast::Block) -> Option<&ast::Expr> {
-    if block.stmts.len() == 1 && block.expr.is_none() {
-        if let ast::StmtKind::Expr(ref expr, _) = block.stmts[0].node {
-            single_stmt_of_expr(expr)
-        } else {
-            None
-        }
-    } else if block.stmts.is_empty() {
-        if let Some(ref p) = block.expr {
-            Some(p)
-        } else {
-            None
+/// If the block contains only one expression, returns it.
+fn expr_block(block: &ast::Block) -> Option<&ast::Expr> {
+    let mut it = block.stmts.iter();
+
+    if let (Some(stmt), None) = (it.next(), it.next()) {
+        match stmt.node {
+            ast::StmtKind::Expr(ref expr) | ast::StmtKind::Semi(ref expr) => Some(expr),
+            _ => None,
         }
     } else {
         None
     }
 }
-
-fn single_stmt_of_expr(expr: &ast::Expr) -> Option<&ast::Expr> {
-    if let ast::ExprKind::Block(ref block) = expr.node {
-        single_stmt_of_block(block)
-    } else {
-        Some(expr)
-    }
-}

tests/compile-fail/collapsible_if.rs

@@ -139,4 +139,9 @@ fn main() {
             println!("world!")
         }
     }
+
+    if true {
+    } else {
+        assert!(true); // assert! is just an `if`
+    }
 }