or_fun_call: lint more methods (#15071)

Extend `or_fun_call` lint with new checks for Option::get_or_insert,
Result::map_or.

changelog: [`or_fun_call`]: lint more methods

Author: samueltardieu

clippy_dev/src/lint.rs

@@ -13,7 +13,7 @@ pub fn run<'a>(path: &str, edition: &str, args: impl Iterator<Item = &'a String>
 
     if is_file {
         exit_if_err(
-            Command::new(env::var("CARGO").unwrap_or("cargo".into()))
+            Command::new(env::var("CARGO").unwrap_or_else(|_| "cargo".into()))
                 .args(["run", "--bin", "clippy-driver", "--"])
                 .args(["-L", "./target/debug"])
                 .args(["-Z", "no-codegen"])
@@ -26,7 +26,7 @@ pub fn run<'a>(path: &str, edition: &str, args: impl Iterator<Item = &'a String>
         );
     } else {
         exit_if_err(
-            Command::new(env::var("CARGO").unwrap_or("cargo".into()))
+            Command::new(env::var("CARGO").unwrap_or_else(|_| "cargo".into()))
                 .arg("build")
                 .status(),
         );

clippy_dev/src/serve.rs

@@ -28,7 +28,7 @@ pub fn run(port: u16, lint: Option<String>) -> ! {
         .map(mtime);
 
         if times.iter().any(|&time| index_time < time) {
-            Command::new(env::var("CARGO").unwrap_or("cargo".into()))
+            Command::new(env::var("CARGO").unwrap_or_else(|_| "cargo".into()))
                 .arg("collect-metadata")
                 .spawn()
                 .unwrap()

clippy_lints/src/attrs/utils.rs

@@ -46,11 +46,13 @@ pub(super) fn is_relevant_trait(cx: &LateContext<'_>, item: &TraitItem<'_>) -> b
 }
 
 fn is_relevant_block(cx: &LateContext<'_>, typeck_results: &ty::TypeckResults<'_>, block: &Block<'_>) -> bool {
-    block.stmts.first().map_or(
-        block
-            .expr
-            .as_ref()
-            .is_some_and(|e| is_relevant_expr(cx, typeck_results, e)),
+    block.stmts.first().map_or_else(
+        || {
+            block
+                .expr
+                .as_ref()
+                .is_some_and(|e| is_relevant_expr(cx, typeck_results, e))
+        },
         |stmt| match &stmt.kind {
             StmtKind::Let(_) => true,
             StmtKind::Expr(expr) | StmtKind::Semi(expr) => is_relevant_expr(cx, typeck_results, expr),

clippy_lints/src/methods/or_fun_call.rs

@@ -136,7 +136,7 @@ pub(super) fn check<'tcx>(
         fun_span: Option<Span>,
     ) -> bool {
         // (path, fn_has_argument, methods, suffix)
-        const KNOW_TYPES: [(Symbol, bool, &[Symbol], &str); 4] = [
+        const KNOW_TYPES: [(Symbol, bool, &[Symbol], &str); 5] = [
             (sym::BTreeEntry, false, &[sym::or_insert], "with"),
             (sym::HashMapEntry, false, &[sym::or_insert], "with"),
             (
@@ -145,16 +145,17 @@ pub(super) fn check<'tcx>(
                 &[sym::map_or, sym::ok_or, sym::or, sym::unwrap_or],
                 "else",
             ),
-            (sym::Result, true, &[sym::or, sym::unwrap_or], "else"),
+            (sym::Option, false, &[sym::get_or_insert], "with"),
+            (sym::Result, true, &[sym::map_or, sym::or, sym::unwrap_or], "else"),
         ];
 
         if KNOW_TYPES.iter().any(|k| k.2.contains(&name))
             && switch_to_lazy_eval(cx, arg)
             && !contains_return(arg)
             && let self_ty = cx.typeck_results().expr_ty(self_expr)
-            && let Some(&(_, fn_has_arguments, poss, suffix)) =
-                KNOW_TYPES.iter().find(|&&i| is_type_diagnostic_item(cx, self_ty, i.0))
-            && poss.contains(&name)
+            && let Some(&(_, fn_has_arguments, _, suffix)) = KNOW_TYPES
+                .iter()
+                .find(|&&i| is_type_diagnostic_item(cx, self_ty, i.0) && i.2.contains(&name))
         {
             let ctxt = span.ctxt();
             let mut app = Applicability::HasPlaceholders;

clippy_utils/src/sym.rs

@@ -167,6 +167,7 @@ generate! {
     futures_util,
     get,
     get_mut,
+    get_or_insert,
     get_or_insert_with,
     get_unchecked,
     get_unchecked_mut,

lintcheck/src/main.rs

@@ -45,7 +45,7 @@ use rayon::prelude::*;
 
 #[must_use]
 pub fn target_dir() -> String {
-    env::var("CARGO_TARGET_DIR").unwrap_or("target".to_owned())
+    env::var("CARGO_TARGET_DIR").unwrap_or_else(|_| "target".to_owned())
 }
 
 fn lintcheck_sources() -> String {

src/main.rs

@@ -107,7 +107,7 @@ impl ClippyCmd {
     }
 
     fn into_std_cmd(self) -> Command {
-        let mut cmd = Command::new(env::var("CARGO").unwrap_or("cargo".into()));
+        let mut cmd = Command::new(env::var("CARGO").unwrap_or_else(|_| "cargo".into()));
         let clippy_args: String = self
             .clippy_args
             .iter()

tests/ui/or_fun_call.fixed

@@ -5,6 +5,7 @@
     clippy::uninlined_format_args,
     clippy::unnecessary_wraps,
     clippy::unnecessary_literal_unwrap,
+    clippy::unnecessary_result_map_or_else,
     clippy::useless_vec
 )]
 
@@ -409,4 +410,33 @@ fn fn_call_in_nested_expr() {
     //~^ or_fun_call
 }
 
+mod result_map_or {
+    fn g() -> i32 {
+        3
+    }
+
+    fn f(n: i32) -> i32 {
+        n
+    }
+
+    fn test_map_or() {
+        let x: Result<i32, ()> = Ok(4);
+        let _ = x.map_or_else(|_| g(), |v| v);
+        //~^ or_fun_call
+        let _ = x.map_or_else(|_| g(), f);
+        //~^ or_fun_call
+        let _ = x.map_or(0, f);
+    }
+}
+
+fn test_option_get_or_insert() {
+    // assume that this is slow call
+    fn g() -> u8 {
+        99
+    }
+    let mut x = Some(42_u8);
+    let _ = x.get_or_insert_with(g);
+    //~^ or_fun_call
+}
+
 fn main() {}

tests/ui/or_fun_call.rs

@@ -5,6 +5,7 @@
     clippy::uninlined_format_args,
     clippy::unnecessary_wraps,
     clippy::unnecessary_literal_unwrap,
+    clippy::unnecessary_result_map_or_else,
     clippy::useless_vec
 )]
 
@@ -409,4 +410,33 @@ fn fn_call_in_nested_expr() {
     //~^ or_fun_call
 }
 
+mod result_map_or {
+    fn g() -> i32 {
+        3
+    }
+
+    fn f(n: i32) -> i32 {
+        n
+    }
+
+    fn test_map_or() {
+        let x: Result<i32, ()> = Ok(4);
+        let _ = x.map_or(g(), |v| v);
+        //~^ or_fun_call
+        let _ = x.map_or(g(), f);
+        //~^ or_fun_call
+        let _ = x.map_or(0, f);
+    }
+}
+
+fn test_option_get_or_insert() {
+    // assume that this is slow call
+    fn g() -> u8 {
+        99
+    }
+    let mut x = Some(42_u8);
+    let _ = x.get_or_insert(g());
+    //~^ or_fun_call
+}
+
 fn main() {}