Account for expect being used to unwrap Option

clippy_lints/src/option_env_unwrap.rs

@@ -38,15 +38,16 @@ impl EarlyLintPass for OptionEnvUnwrap {
         if_chain! {
             if !in_external_macro(cx.sess, expr.span);
             if let ExprKind::MethodCall(path_segment, args) = &expr.kind;
-            if path_segment.ident.as_str() == "unwrap";
+            let method_name = path_segment.ident.as_str();
+            if method_name == "expect" || method_name == "unwrap";
             if let ExprKind::Call(caller, _) = &args[0].kind;
             if is_direct_expn_of(caller.span, "option_env").is_some();
             then {
                 span_lint_and_help(
                     cx,
                     OPTION_ENV_UNWRAP,
                     expr.span,
-                    "this will panic at run-time if the environment variable doesn't exist",
+                    "this will panic at run-time if the environment variable doesn't exist at compile-time",
                     "consider using the `env!` macro instead"
                 );
             }

tests/ui/option_env_unwrap.rs

@@ -4,9 +4,14 @@ macro_rules! option_env_unwrap {
     ($env: expr) => {
         option_env!($env).unwrap()
     };
+    ($env: expr, $message: expr) => {
+        option_env!($env).expect($message)
+    };
 }
 
 fn main() {
     let _ = option_env!("HOME").unwrap();
+    let _ = option_env!("HOME").expect("environment variable HOME isn't set");
     let _ = option_env_unwrap!("HOME");
+    let _ = option_env_unwrap!("HOME", "environment variable HOME isn't set");
 }

tests/ui/option_env_unwrap.stderr

@@ -1,13 +1,21 @@
-error: this will panic at run-time if the environment variable doesn't exist
-  --> $DIR/option_env_unwrap.rs:10:13
+error: this will panic at run-time if the environment variable doesn't exist at compile-time
+  --> $DIR/option_env_unwrap.rs:13:13
    |
 LL |     let _ = option_env!("HOME").unwrap();
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `-D clippy::option-env-unwrap` implied by `-D warnings`
    = help: consider using the `env!` macro instead
 
-error: this will panic at run-time if the environment variable doesn't exist
+error: this will panic at run-time if the environment variable doesn't exist at compile-time
+  --> $DIR/option_env_unwrap.rs:14:13
+   |
+LL |     let _ = option_env!("HOME").expect("environment variable HOME isn't set");
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: consider using the `env!` macro instead
+
+error: this will panic at run-time if the environment variable doesn't exist at compile-time
   --> $DIR/option_env_unwrap.rs:5:9
    |
 LL |         option_env!($env).unwrap()
@@ -19,5 +27,17 @@ LL |     let _ = option_env_unwrap!("HOME");
    = help: consider using the `env!` macro instead
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
 
-error: aborting due to 2 previous errors
+error: this will panic at run-time if the environment variable doesn't exist at compile-time
+  --> $DIR/option_env_unwrap.rs:8:9
+   |
+LL |         option_env!($env).expect($message)
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+...
+LL |     let _ = option_env_unwrap!("HOME", "environment variable HOME isn't set");
+   |             ----------------------------------------------------------------- in this macro invocation
+   |
+   = help: consider using the `env!` macro instead
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 4 previous errors