Deprecate redundant lint `option_map_or_err_ok` and take `manual_ok_or` out of pedantic (#14027)

While extending the `option_map_or_err_ok` lint (warn by default,
"style") to recognize η-expanded forms of `Ok`, as in

```rust
    // Should suggest `opt.ok_or("foobar")`
   let _ = opt.map_or(Err("foobar"), |x| Ok(x));
```

I discovered that the `manual_ok_or` lint (allow by default, "pedantic")
already covered exactly the cases handled by `option_map_or_err_ok`,
including the one I was adding. Apparently, `option_map_or_err_ok` was
added without realizing that the lint already existed under the
`manual_ok_or` name. As a matter of fact, artifacts of this second lint
were even present in the first lint `stderr` file and went unnoticed for
more than a year.

This PR:
- deprecates `option_map_or_err_ok` with a message saying to use
`manual_ok_or`
- moves `manual_ok_or` from "pedantic" to "style" (the category in which
`option_map_or_err_ok` was)

In addition, I think that this lint, which is short, machine applicable,
and leads to shorter and clearer code with less arguments (`Ok`
disappears) and the removal of one level of call (`Err(x)` is replaced
by `x`), is a reason by itself to be in "style".

changelog: [`option_map_or_err_ok` and `manual_ok_or`]: move
`manual_ok_or` from "pedantic" to "style", and deprecate the redundant
style lint `option_map_or_err_ok`.

2 files changed, 1 insertions, 70 deletions

diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs
index f501cf060c2..f151dedc244 100644
--- a/clippy_lints/src/methods/mod.rs
+++ b/clippy_lints/src/methods/mod.rs
@@ -82,7 +82,6 @@ mod ok_expect;
 mod open_options;
 mod option_as_ref_cloned;
 mod option_as_ref_deref;
-mod option_map_or_err_ok;
 mod option_map_or_none;
 mod option_map_unwrap_or;
 mod or_fun_call;
@@ -2641,7 +2640,7 @@ declare_clippy_lint! {
     /// ```
     #[clippy::version = "1.49.0"]
     pub MANUAL_OK_OR,
-    pedantic,
+    style,
     "finds patterns that can be encoded more concisely with `Option::ok_or`"
 }
 
@@ -3785,31 +3784,6 @@ declare_clippy_lint! {
 
 declare_clippy_lint! {
     /// ### What it does
-    /// Checks for usage of `_.map_or(Err(_), Ok)`.
-    ///
-    /// ### Why is this bad?
-    /// Readability, this can be written more concisely as
-    /// `_.ok_or(_)`.
-    ///
-    /// ### Example
-    /// ```no_run
-    /// # let opt = Some(1);
-    /// opt.map_or(Err("error"), Ok);
-    /// ```
-    ///
-    /// Use instead:
-    /// ```no_run
-    /// # let opt = Some(1);
-    /// opt.ok_or("error");
-    /// ```
-    #[clippy::version = "1.76.0"]
-    pub OPTION_MAP_OR_ERR_OK,
-    style,
-    "using `Option.map_or(Err(_), Ok)`, which is more succinctly expressed as `Option.ok_or(_)`"
-}
-
-declare_clippy_lint! {
-    /// ### What it does
     /// Checks for iterators of `Result`s using `.filter(Result::is_ok).map(Result::unwrap)` that may
     /// be replaced with a `.flatten()` call.
     ///
@@ -4579,7 +4553,6 @@ impl_lint_pass!(Methods => [
     WAKER_CLONE_WAKE,
     UNNECESSARY_FALLIBLE_CONVERSIONS,
     JOIN_ABSOLUTE_PATHS,
-    OPTION_MAP_OR_ERR_OK,
     RESULT_FILTER_MAP,
     ITER_FILTER_IS_SOME,
     ITER_FILTER_IS_OK,
@@ -5146,7 +5119,6 @@ impl Methods {
                 ("map_or", [def, map]) => {
                     option_map_or_none::check(cx, expr, recv, def, map);
                     manual_ok_or::check(cx, expr, recv, def, map);
-                    option_map_or_err_ok::check(cx, expr, recv, def, map);
                     unnecessary_map_or::check(cx, expr, recv, def, map, span, &self.msrv);
                 },
                 ("map_or_else", [def, map]) => {
diff --git a/clippy_lints/src/methods/option_map_or_err_ok.rs b/clippy_lints/src/methods/option_map_or_err_ok.rs
deleted file mode 100644
index 4e424d4c066..00000000000
--- a/clippy_lints/src/methods/option_map_or_err_ok.rs
+++ /dev/null
@@ -1,41 +0,0 @@
-use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::source::snippet;
-use clippy_utils::ty::is_type_diagnostic_item;
-use clippy_utils::{is_res_lang_ctor, path_res};
-use rustc_errors::Applicability;
-use rustc_hir::LangItem::{ResultErr, ResultOk};
-use rustc_hir::{Expr, ExprKind};
-use rustc_lint::LateContext;
-use rustc_span::symbol::sym;
-
-use super::OPTION_MAP_OR_ERR_OK;
-
-pub(super) fn check<'tcx>(
-    cx: &LateContext<'tcx>,
-    expr: &'tcx Expr<'tcx>,
-    recv: &'tcx Expr<'_>,
-    or_expr: &'tcx Expr<'_>,
-    map_expr: &'tcx Expr<'_>,
-) {
-    // We check that it's called on an `Option` type.
-    if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(recv), sym::Option)
-        // We check that first we pass an `Err`.
-        && let ExprKind::Call(call, &[arg]) = or_expr.kind
-        && is_res_lang_ctor(cx, path_res(cx, call), ResultErr)
-        // And finally we check that it is mapped as `Ok`.
-        && is_res_lang_ctor(cx, path_res(cx, map_expr), ResultOk)
-    {
-        let msg = "called `map_or(Err(_), Ok)` on an `Option` value";
-        let self_snippet = snippet(cx, recv.span, "..");
-        let err_snippet = snippet(cx, arg.span, "..");
-        span_lint_and_sugg(
-            cx,
-            OPTION_MAP_OR_ERR_OK,
-            expr.span,
-            msg,
-            "consider using `ok_or`",
-            format!("{self_snippet}.ok_or({err_snippet})"),
-            Applicability::MachineApplicable,
-        );
-    }
-}