From 6a566a1009fefdbfe30e8475836f6b06fed81b3c Mon Sep 17 00:00:00 2001
From: Oliver Schneider <git-spam-no-reply9815368754983@oli-obk.de>
Date: Mon, 14 Mar 2016 17:13:10 +0100
Subject: [PATCH] use snippet_opt and span_suggestion

---
 src/needless_bool.rs                | 20 ++++++++++----------
 tests/compile-fail/needless_bool.rs | 20 ++++++++++++++++----
 2 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/src/needless_bool.rs b/src/needless_bool.rs
index 58afc86b82c..43e7cfddadd 100644
--- a/src/needless_bool.rs
+++ b/src/needless_bool.rs
@@ -6,7 +6,7 @@ use rustc::lint::*;
 use rustc_front::hir::*;
 use syntax::ast::LitKind;
 use syntax::codemap::Spanned;
-use utils::{span_lint, span_lint_and_then, snippet};
+use utils::{span_lint, span_lint_and_then, snippet, snippet_opt};
 
 /// **What it does:** This lint checks for expressions of the form `if c { true } else { false }` (or vice versa) and suggest using the condition directly.
 ///
@@ -50,16 +50,16 @@ impl LateLintPass for NeedlessBool {
         use self::Expression::*;
         if let ExprIf(ref pred, ref then_block, Some(ref else_expr)) = e.node {
             let reduce = |hint: &str, not| {
-                let pred_snip = snippet(cx, pred.span, "..");
-                let hint = if pred_snip == ".." {
-                    hint.into()
-                } else {
-                    format!("`{}{}`", not, pred_snip)
+                let hint = match snippet_opt(cx, pred.span) {
+                    Some(pred_snip) => format!("`{}{}`", not, pred_snip),
+                    None => hint.into(),
                 };
-                span_lint(cx,
-                          NEEDLESS_BOOL,
-                          e.span,
-                          &format!("you can reduce this if-then-else expression to just {}", hint));
+                span_lint_and_then(cx,
+                                   NEEDLESS_BOOL,
+                                   e.span,
+                                   "this if-then-else expression returns a bool literal", |db| {
+                    db.span_suggestion(e.span, "you can reduce it to", hint);
+                });
             };
             match (fetch_bool_block(then_block), fetch_bool_expr(else_expr)) {
                 (RetBool(true), RetBool(true)) |
diff --git a/tests/compile-fail/needless_bool.rs b/tests/compile-fail/needless_bool.rs
index eff2bdc9b28..7f2d7754bda 100644
--- a/tests/compile-fail/needless_bool.rs
+++ b/tests/compile-fail/needless_bool.rs
@@ -7,8 +7,14 @@ fn main() {
     let x = true;
     if x { true } else { true }; //~ERROR this if-then-else expression will always return true
     if x { false } else { false }; //~ERROR this if-then-else expression will always return false
-    if x { true } else { false }; //~ERROR you can reduce this if-then-else expression to just `x`
-    if x { false } else { true }; //~ERROR you can reduce this if-then-else expression to just `!x`
+    if x { true } else { false };
+    //~^ ERROR this if-then-else expression returns a bool literal
+    //~| HELP you can reduce it to
+    //~| SUGGESTION `x`
+    if x { false } else { true };
+    //~^ ERROR this if-then-else expression returns a bool literal
+    //~| HELP you can reduce it to
+    //~| SUGGESTION `!x`
     if x { x } else { false }; // would also be questionable, but we don't catch this yet
     bool_ret(x);
     bool_ret2(x);
@@ -30,10 +36,16 @@ fn bool_ret2(x: bool) -> bool {
 
 #[deny(needless_bool)]
 fn bool_ret3(x: bool) -> bool {
-    if x { return true } else { return false }; //~ERROR you can reduce this if-then-else expression to just `return x`
+    if x { return true } else { return false };
+    //~^ ERROR this if-then-else expression returns a bool literal
+    //~| HELP you can reduce it to
+    //~| SUGGESTION `return x`
 }
 
 #[deny(needless_bool)]
 fn bool_ret4(x: bool) -> bool {
-    if x { return false } else { return true }; //~ERROR you can reduce this if-then-else expression to just `return !x`
+    if x { return false } else { return true };
+    //~^ ERROR this if-then-else expression returns a bool literal
+    //~| HELP you can reduce it to
+    //~| SUGGESTION `return !x`
 }