From 47fb67fa086d88a878c11d7edc38f322f3b98fb9 Mon Sep 17 00:00:00 2001
From: Jason Newcomb <jsnewcomb@pm.me>
Date: Thu, 1 Dec 2022 12:30:19 -0500
Subject: [PATCH] Don't lint `manual_assert` in `else if`

---
 clippy_lints/src/manual_assert.rs         | 6 +++++-
 tests/ui/manual_assert.edition2018.fixed  | 5 +++++
 tests/ui/manual_assert.edition2021.fixed  | 5 +++++
 tests/ui/manual_assert.edition2021.stderr | 2 +-
 tests/ui/manual_assert.rs                 | 5 +++++
 5 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/clippy_lints/src/manual_assert.rs b/clippy_lints/src/manual_assert.rs
index b8ed9b9ec18f7..4277455a3a21c 100644
--- a/clippy_lints/src/manual_assert.rs
+++ b/clippy_lints/src/manual_assert.rs
@@ -2,7 +2,7 @@ use crate::rustc_lint::LintContext;
 use clippy_utils::diagnostics::span_lint_and_then;
 use clippy_utils::macros::{root_macro_call, FormatArgsExpn};
 use clippy_utils::source::snippet_with_applicability;
-use clippy_utils::{peel_blocks_with_stmt, span_extract_comment, sugg};
+use clippy_utils::{is_else_clause, peel_blocks_with_stmt, span_extract_comment, sugg};
 use rustc_errors::Applicability;
 use rustc_hir::{Expr, ExprKind, UnOp};
 use rustc_lint::{LateContext, LateLintPass};
@@ -47,6 +47,10 @@ impl<'tcx> LateLintPass<'tcx> for ManualAssert {
             if cx.tcx.item_name(macro_call.def_id) == sym::panic;
             if !cx.tcx.sess.source_map().is_multiline(cond.span);
             if let Some(format_args) = FormatArgsExpn::find_nested(cx, then, macro_call.expn);
+            // Don't change `else if foo { panic!(..) }` to `else { assert!(foo, ..) }` as it just
+            // shuffles the condition around.
+            // Should this have a config value?
+            if !is_else_clause(cx.tcx, expr);
             then {
                 let mut applicability = Applicability::MachineApplicable;
                 let format_args_snip = snippet_with_applicability(cx, format_args.inputs_span(), "..", &mut applicability);
diff --git a/tests/ui/manual_assert.edition2018.fixed b/tests/ui/manual_assert.edition2018.fixed
index c9a819ba53544..638320dd6eec4 100644
--- a/tests/ui/manual_assert.edition2018.fixed
+++ b/tests/ui/manual_assert.edition2018.fixed
@@ -62,6 +62,11 @@ fn main() {
         panic!("panic5");
     }
     assert!(!a.is_empty(), "with expansion {}", one!());
+    if a.is_empty() {
+        let _ = 0;
+    } else if a.len() == 1 {
+        panic!("panic6");
+    }
 }
 
 fn issue7730(a: u8) {
diff --git a/tests/ui/manual_assert.edition2021.fixed b/tests/ui/manual_assert.edition2021.fixed
index 2f62de51cadcd..8c7e919bf62a1 100644
--- a/tests/ui/manual_assert.edition2021.fixed
+++ b/tests/ui/manual_assert.edition2021.fixed
@@ -50,6 +50,11 @@ fn main() {
     assert!(!(b.is_empty() || a.is_empty()), "panic4");
     assert!(!(a.is_empty() || !b.is_empty()), "panic5");
     assert!(!a.is_empty(), "with expansion {}", one!());
+    if a.is_empty() {
+        let _ = 0;
+    } else if a.len() == 1 {
+        panic!("panic6");
+    }
 }
 
 fn issue7730(a: u8) {
diff --git a/tests/ui/manual_assert.edition2021.stderr b/tests/ui/manual_assert.edition2021.stderr
index 237638ee1344c..3555ac29243a1 100644
--- a/tests/ui/manual_assert.edition2021.stderr
+++ b/tests/ui/manual_assert.edition2021.stderr
@@ -65,7 +65,7 @@ LL | |     }
    | |_____^ help: try instead: `assert!(!a.is_empty(), "with expansion {}", one!());`
 
 error: only a `panic!` in `if`-then statement
-  --> $DIR/manual_assert.rs:73:5
+  --> $DIR/manual_assert.rs:78:5
    |
 LL | /     if a > 2 {
 LL | |         // comment
diff --git a/tests/ui/manual_assert.rs b/tests/ui/manual_assert.rs
index 6a4cc2468d419..f037c5b8405c7 100644
--- a/tests/ui/manual_assert.rs
+++ b/tests/ui/manual_assert.rs
@@ -66,6 +66,11 @@ fn main() {
     if a.is_empty() {
         panic!("with expansion {}", one!())
     }
+    if a.is_empty() {
+        let _ = 0;
+    } else if a.len() == 1 {
+        panic!("panic6");
+    }
 }
 
 fn issue7730(a: u8) {