Merge remote-tracking branch 'upstream/master' into rustup

[rust.git] / clippy_lints / src / if_let_some_result.rs

diff --git a/clippy_lints/src/if_let_some_result.rs b/clippy_lints/src/if_let_some_result.rs
index dc129a28e3707bd5d2dd1277e2201a43e70c8543..1194bd7e55e2566e5ad5c20f741d8888829e5e5f 100644 (file)
--- a/clippy_lints/src/if_let_some_result.rs
+++ b/clippy_lints/src/if_let_some_result.rs
@@ -1,10 +1,10 @@
-use crate::utils::{match_type, method_chain_args, paths, snippet, snippet_with_applicability, span_lint_and_sugg};
+use crate::utils::{is_type_diagnostic_item, method_chain_args, snippet_with_applicability, span_lint_and_sugg};
 use if_chain::if_chain;
 use rustc_errors::Applicability;
-use rustc_hir::*;
+use rustc_hir::{Expr, ExprKind, MatchSource, PatKind, QPath};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
-use rustc_span::BytePos;
+use rustc_span::sym;
 
 declare_clippy_lint! {
     /// **What it does:*** Checks for unnecessary `ok()` in if let.
@@ -38,41 +38,34 @@
 
 declare_lint_pass!(OkIfLet => [IF_LET_SOME_RESULT]);
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for OkIfLet {
-    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+impl<'tcx> LateLintPass<'tcx> for OkIfLet {
+    fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
         if_chain! { //begin checking variables
-            if let ExprKind::Match(ref op, ref body, source) = expr.kind; //test if expr is a match
-            if let MatchSource::IfLetDesugar { contains_else_clause } = source; //test if it is an If Let
-            if let ExprKind::MethodCall(_, ok_span, ref result_types) = op.kind; //check is expr.ok() has type Result<T,E>.ok()
+            if let ExprKind::Match(ref op, ref body, MatchSource::IfLetDesugar { .. }) = expr.kind; //test if expr is if let
+            if let ExprKind::MethodCall(_, ok_span, ref result_types, _) = op.kind; //check is expr.ok() has type Result<T,E>.ok(, _)
             if let PatKind::TupleStruct(QPath::Resolved(_, ref x), ref y, _)  = body[0].pat.kind; //get operation
             if method_chain_args(op, &["ok"]).is_some(); //test to see if using ok() methoduse std::marker::Sized;
+            if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&result_types[0]), sym::result_type);
+            if rustc_hir_pretty::to_string(rustc_hir_pretty::NO_ANN, |s| s.print_path(x, false)) == "Some";
 
             then {
-                let is_result_type = match_type(cx, cx.tables.expr_ty(&result_types[0]), &paths::RESULT);
                 let mut applicability = Applicability::MachineApplicable;
-                let trimed_ok_span = op.span.until(op.span.with_lo(ok_span.lo() - BytePos(1)));
                 let some_expr_string = snippet_with_applicability(cx, y[0].span, "", &mut applicability);
-                let trimmed_ok = snippet_with_applicability(cx, trimed_ok_span, "", &mut applicability);
-                let mut sugg = format!(
-                    "if let Ok({}) = {} {}",
+                let trimmed_ok = snippet_with_applicability(cx, op.span.until(ok_span), "", &mut applicability);
+                let sugg = format!(
+                    "if let Ok({}) = {}",
                     some_expr_string,
-                    trimmed_ok,
-                    snippet(cx, body[0].span, ".."),
+                    trimmed_ok.trim().trim_end_matches('.'),
+                );
+                span_lint_and_sugg(
+                    cx,
+                    IF_LET_SOME_RESULT,
+                    expr.span.with_hi(op.span.hi()),
+                    "matching on `Some` with `ok()` is redundant",
+                    &format!("consider matching on `Ok({})` and removing the call to `ok` instead", some_expr_string),
+                    sugg,
+                    applicability,
                 );
-                if contains_else_clause {
-                    sugg = format!("{} else {}", sugg, snippet(cx, body[1].span, ".."));
-                }
-                if print::to_string(print::NO_ANN, |s| s.print_path(x, false)) == "Some" && is_result_type {
-                    span_lint_and_sugg(
-                        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),
-                        sugg,
-                        applicability,
-                    );
-                }
             }
         }
     }