Merge pull request #1764 from Manishearth/debug_assert

distinguish debug_assert

clippy_lints/src/should_assert_eq.rs

@@ -1,6 +1,6 @@
 use rustc::lint::*;
 use rustc::hir::*;
-use utils::{is_direct_expn_of, implements_trait, span_lint};
+use utils::{is_direct_expn_of, is_expn_of, implements_trait, span_lint};
 
 /// **What it does:** Checks for `assert!(x == y)` or `assert!(x != y)` which can be better written
 /// using `assert_eq` or `assert_ne` if `x` and `y` implement `Debug` trait.
@@ -39,6 +39,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ShouldAssertEq {
             is_direct_expn_of(e.span, "assert").is_some(),
             let Some(debug_trait) = cx.tcx.lang_items.debug_trait(),
         ], {
+            let debug = is_expn_of(e.span, "debug_assert").map_or("", |_| "debug_");
             let sugg = match binop.node {
                 BinOp_::BiEq => "assert_eq",
                 BinOp_::BiNe => "assert_ne",
@@ -52,7 +53,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for ShouldAssertEq {
 
             if implements_trait(cx, ty1, debug_trait, &[], Some(parent)) &&
                 implements_trait(cx, ty2, debug_trait, &[], Some(parent)) {
-                span_lint(cx, SHOULD_ASSERT_EQ, e.span, &format!("use `{}` for better reporting", sugg));
+                span_lint(cx, SHOULD_ASSERT_EQ, e.span, &format!("use `{}{}` for better reporting", debug, sugg));
             }
         }}
     }

tests/ui/should_assert_eq.rs

@@ -18,6 +18,9 @@ fn main() {
     assert!(NonDebug(1) != NonDebug(2)); // ok
 
     test_generic(1, 2, 3, 4);
+
+    debug_assert!(4 == 5);
+    debug_assert!(4 != 6);
 }
 
 fn test_generic<T: std::fmt::Debug + Eq, U: Eq>(x: T, y: T, z: U, w: U) {

tests/ui/should_assert_eq.stderr

@@ -27,21 +27,37 @@ error: use `assert_ne` for better reporting
    |
    = note: this error originates in a macro outside of the current crate
 
-error: use `assert_eq` for better reporting
-  --> $DIR/should_assert_eq.rs:24:5
+error: use `debug_assert_eq` for better reporting
+  --> $DIR/should_assert_eq.rs:22:5
    |
-24 |     assert!(x == y);
+22 |     debug_assert!(4 == 5);
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in a macro outside of the current crate
+
+error: use `debug_assert_ne` for better reporting
+  --> $DIR/should_assert_eq.rs:23:5
+   |
+23 |     debug_assert!(4 != 6);
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in a macro outside of the current crate
+
+error: use `assert_eq` for better reporting
+  --> $DIR/should_assert_eq.rs:27:5
+   |
+27 |     assert!(x == y);
    |     ^^^^^^^^^^^^^^^^
    |
    = note: this error originates in a macro outside of the current crate
 
 error: use `assert_ne` for better reporting
-  --> $DIR/should_assert_eq.rs:27:5
+  --> $DIR/should_assert_eq.rs:30:5
    |
-27 |     assert!(x != y);
+30 |     assert!(x != y);
    |     ^^^^^^^^^^^^^^^^
    |
    = note: this error originates in a macro outside of the current crate
 
-error: aborting due to 5 previous errors
+error: aborting due to 7 previous errors