-use rustc::lint::*;
+// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use crate::utils::{match_type, method_chain_args, paths, snippet, span_help_and_lint};
+use if_chain::if_chain;
use rustc::hir::*;
-use utils::{paths, method_chain_args, span_help_and_lint, match_type, snippet};
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc::{declare_tool_lint, lint_array};
/// **What it does:*** Checks for unnecessary `ok()` in if let.
///
-/// **Why is this bad?** Calling `ok()` in if let is unnecessary, instead match on `Ok(pat)`
+/// **Why is this bad?** Calling `ok()` in if let is unnecessary, instead match
+/// on `Ok(pat)`
///
/// **Known problems:** None.
///
/// }
/// }
/// ```
-declare_lint! {
+declare_clippy_lint! {
pub IF_LET_SOME_RESULT,
- Warn,
+ style,
"usage of `ok()` in `if let Some(pat)` statements is unnecessary, match on `Ok(pat)` instead"
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
- if_let_chain! {[ //begin checking variables
- let ExprMatch(ref op, ref body, ref source) = expr.node, //test if expr is a match
- let MatchSource::IfLetDesugar { .. } = *source, //test if it is an If Let
- let ExprMethodCall(_, _, ref result_types) = op.node, //check is expr.ok() has type Result<T,E>.ok()
- let PatKind::TupleStruct(QPath::Resolved(_, ref x), ref y, _) = body[0].pats[0].node, //get operation
- method_chain_args(op, &["ok"]).is_some() //test to see if using ok() methoduse std::marker::Sized;
+ if_chain! { //begin checking variables
+ if let ExprKind::Match(ref op, ref body, ref source) = expr.node; //test if expr is a match
+ if let MatchSource::IfLetDesugar { .. } = *source; //test if it is an If Let
+ if let ExprKind::MethodCall(_, _, ref result_types) = op.node; //check is expr.ok() has type Result<T,E>.ok()
+ if let PatKind::TupleStruct(QPath::Resolved(_, ref x), ref y, _) = body[0].pats[0].node; //get operation
+ if method_chain_args(op, &["ok"]).is_some(); //test to see if using ok() methoduse std::marker::Sized;
- ], {
- let is_result_type = match_type(cx, cx.tables.expr_ty(&result_types[0]), &paths::RESULT);
- let some_expr_string = snippet(cx, y[0].span, "");
- if print::to_string(print::NO_ANN, |s| s.print_path(x, false)) == "Some" && is_result_type {
- span_help_and_lint(cx, IF_LET_SOME_RESULT, expr.span,
- "Matching on `Some` with `ok()` is redundant",
- &format!("Consider matching on `Ok({})` and removing the call to `ok` instead", some_expr_string));
+ then {
+ let is_result_type = match_type(cx, cx.tables.expr_ty(&result_types[0]), &paths::RESULT);
+ let some_expr_string = snippet(cx, y[0].span, "");
+ if print::to_string(print::NO_ANN, |s| s.print_path(x, false)) == "Some" && is_result_type {
+ span_help_and_lint(cx, IF_LET_SOME_RESULT, expr.span,
+ "Matching on `Some` with `ok()` is redundant",
+ &format!("Consider matching on `Ok({})` and removing the call to `ok` instead", some_expr_string));
+ }
}
- }}
+ }
}
}