X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Fok_if_let.rs;h=e060220d56b31840cd56a8ad388af989a89d43cd;hb=4d60841205d10293d6759df1948acda4c607c7eb;hp=b7e7c70e41a5cd708965ced0317ca40c353b514c;hpb=59b0077565bc056283dad048a237dbc183000c76;p=rust.git diff --git a/clippy_lints/src/ok_if_let.rs b/clippy_lints/src/ok_if_let.rs index b7e7c70e41a..e060220d56b 100644 --- a/clippy_lints/src/ok_if_let.rs +++ b/clippy_lints/src/ok_if_let.rs @@ -1,10 +1,22 @@ -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 or the MIT license +// , 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. /// @@ -15,7 +27,7 @@ /// vec.push(bench) /// } /// } -///``` +/// ``` /// Could be written: /// /// ```rust @@ -25,9 +37,9 @@ /// } /// } /// ``` -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" } @@ -40,23 +52,24 @@ fn get_lints(&self) -> LintArray { } } -impl LateLintPass for Pass { - fn check_expr(&mut self, cx: &LateContext, expr: &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.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; +impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass { + fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) { + 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.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.tcx.tables().expr_ty(&result_types[0]), &paths::RESULT); - let some_expr_string = snippet(cx, y[0].span, ""); - if print::path_to_string(x) == "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)); + } } - }} + } } }