Do not lint unnecessary_unwrap in macros

clippy_lints/src/unwrap.rs

@@ -1,4 +1,4 @@
-use crate::utils::{higher::if_block, match_type, paths, span_lint_and_then, usage::is_potentially_mutated};
+use crate::utils::{higher::if_block, in_macro, match_type, paths, span_lint_and_then, usage::is_potentially_mutated};
 use if_chain::if_chain;
 use rustc::hir::map::Map;
 use rustc_hir::intravisit::*;
@@ -138,6 +138,10 @@ impl<'a, 'tcx> Visitor<'tcx> for UnwrappableVariablesVisitor<'a, 'tcx> {
     type Map = Map<'tcx>;
 
     fn visit_expr(&mut self, expr: &'tcx Expr<'_>) {
+        // Shouldn't lint when `expr` is in macro.
+        if in_macro(expr.span) {
+            return;
+        }
         if let Some((cond, then, els)) = if_block(&expr) {
             walk_expr(self, cond);
             self.visit_branch(cond, then, false);

tests/ui/checked_unwrap/simple_conditionals.rs

@@ -39,4 +39,6 @@ fn main() {
                         // it will always panic but the lint is not smart enough to see this (it
                         // only checks if conditions).
     }
+
+    assert!(x.is_ok(), "{:?}", x.unwrap_err()); // ok, it's a common test pattern
 }