Merge pull request #1444 from Manishearth/or_else_method

Extend or_fun_call to also cover methods

clippy_lints/src/methods.rs

@@ -724,7 +724,7 @@ fn lint_or_fun_call(cx: &LateContext, expr: &hir::Expr, name: &str, args: &[hir:
     fn check_general_case(
         cx: &LateContext,
         name: &str,
-        fun: &hir::Expr,
+        fun_span: Span,
         self_expr: &hir::Expr,
         arg: &hir::Expr,
         or_has_args: bool,
@@ -765,7 +765,7 @@ fn lint_or_fun_call(cx: &LateContext, expr: &hir::Expr, name: &str, args: &[hir:
         let sugg: Cow<_> = match (fn_has_arguments, !or_has_args) {
             (true, _) => format!("|_| {}", snippet(cx, arg.span, "..")).into(),
             (false, false) => format!("|| {}", snippet(cx, arg.span, "..")).into(),
-            (false, true) => snippet(cx, fun.span, ".."),
+            (false, true) => snippet(cx, fun_span, ".."),
         };
 
         span_lint_and_then(cx,
@@ -780,11 +780,17 @@ fn lint_or_fun_call(cx: &LateContext, expr: &hir::Expr, name: &str, args: &[hir:
     }
 
     if args.len() == 2 {
-        if let hir::ExprCall(ref fun, ref or_args) = args[1].node {
-            let or_has_args = !or_args.is_empty();
-            if !check_unwrap_or_default(cx, name, fun, &args[0], &args[1], or_has_args, expr.span) {
-                check_general_case(cx, name, fun, &args[0], &args[1], or_has_args, expr.span);
-            }
+        match args[1].node {
+            hir::ExprCall(ref fun, ref or_args) => {
+                let or_has_args = !or_args.is_empty();
+                if !check_unwrap_or_default(cx, name, fun, &args[0], &args[1], or_has_args, expr.span) {
+                    check_general_case(cx, name, fun.span, &args[0], &args[1], or_has_args, expr.span);
+                }
+            },
+            hir::ExprMethodCall(fun, _, ref or_args) => {
+                check_general_case(cx, name, fun.span, &args[0], &args[1], !or_args.is_empty(), expr.span)
+            },
+            _ => {},
         }
     }
 }

src/main.rs

@@ -234,13 +234,15 @@ pub fn main() {
         } else {
             option_env!("SYSROOT")
                 .map(|s| s.to_owned())
-                .or(Command::new("rustc")
-                    .arg("--print")
-                    .arg("sysroot")
-                    .output()
-                    .ok()
-                    .and_then(|out| String::from_utf8(out.stdout).ok())
-                    .map(|s| s.trim().to_owned()))
+                .or_else(|| {
+                    Command::new("rustc")
+                        .arg("--print")
+                        .arg("sysroot")
+                        .output()
+                        .ok()
+                        .and_then(|out| String::from_utf8(out.stdout).ok())
+                        .map(|s| s.trim().to_owned())
+                })
                 .expect("need to specify SYSROOT env var during clippy compilation, or use rustup or multirust")
         };
 

tests/compile-fail/methods.rs

@@ -127,7 +127,6 @@ fn option_methods() {
                 );
     // macro case
     let _ = opt_map!(opt, |x| x + 1).unwrap_or_else(|| 0); // should not lint
-
 }
 
 /// Struct to generate false positives for things with .iter()
@@ -340,6 +339,12 @@ fn or_fun_call() {
     //~^ERROR use of `or_insert` followed by a function call
     //~|HELP try this
     //~|SUGGESTION btree.entry(42).or_insert_with(String::new);
+
+    let stringy = Some(String::from(""));
+    let _ = stringy.unwrap_or("".to_owned());
+    //~^ERROR use of `unwrap_or`
+    //~|HELP try this
+    //~|SUGGESTION stringy.unwrap_or_else(|| "".to_owned());
 }
 
 /// Checks implementation of `ITER_NTH` lint