Auto merge of rust-lang#15752 - Young-Flash:replace_is_method_with_if_let_method, r=HKalbasi

feat: add replace_is_ok_with_if_let_ok assist

following rust-lang/rust-analyzer#15743

Author: bors

Diff for: crates/ide-assists/src/handlers/replace_is_method_with_if_let_method.rs

@@ -0,0 +1,124 @@
+use syntax::ast::{self, AstNode};
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: replace_is_some_with_if_let_some
+//
+// Replace `if x.is_some()` with `if let Some(_tmp) = x` or `if x.is_ok()` with `if let Ok(_tmp) = x`.
+//
+// ```
+// fn main() {
+//     let x = Some(1);
+//     if x.is_som$0e() {}
+// }
+// ```
+// ->
+// ```
+// fn main() {
+//     let x = Some(1);
+//     if let Some(_tmp) = x {}
+// }
+// ```
+pub(crate) fn replace_is_method_with_if_let_method(
+    acc: &mut Assists,
+    ctx: &AssistContext<'_>,
+) -> Option<()> {
+    let if_expr = ctx.find_node_at_offset::<ast::IfExpr>()?;
+
+    let cond = if_expr.condition()?;
+    let call_expr = match cond {
+        ast::Expr::MethodCallExpr(call) => call,
+        _ => return None,
+    };
+
+    let name_ref = call_expr.name_ref()?;
+    match name_ref.text().as_str() {
+        "is_some" | "is_ok" => {
+            let receiver = call_expr.receiver()?;
+            let target = call_expr.syntax().text_range();
+
+            let (assist_id, message, text) = if name_ref.text() == "is_some" {
+                ("replace_is_some_with_if_let_some", "Replace `is_some` with `if let Some`", "Some")
+            } else {
+                ("replace_is_ok_with_if_let_ok", "Replace `is_ok` with `if let Ok`", "Ok")
+            };
+
+            acc.add(AssistId(assist_id, AssistKind::RefactorRewrite), message, target, |edit| {
+                let replacement = format!("let {}(_tmp) = {}", text, receiver);
+                edit.replace(target, replacement);
+            })
+        }
+        _ => return None,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::{check_assist, check_assist_not_applicable};
+
+    use super::replace_is_method_with_if_let_method;
+
+    #[test]
+    fn replace_is_some_with_if_let_some_works() {
+        check_assist(
+            replace_is_method_with_if_let_method,
+            r#"
+fn main() {
+    let x = Some(1);
+    if x.is_som$0e() {}
+}
+"#,
+            r#"
+fn main() {
+    let x = Some(1);
+    if let Some(_tmp) = x {}
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn replace_is_some_with_if_let_some_not_applicable() {
+        check_assist_not_applicable(
+            replace_is_method_with_if_let_method,
+            r#"
+fn main() {
+    let x = Some(1);
+    if x.is_non$0e() {}
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn replace_is_ok_with_if_let_ok_works() {
+        check_assist(
+            replace_is_method_with_if_let_method,
+            r#"
+fn main() {
+    let x = Ok(1);
+    if x.is_o$0k() {}
+}
+"#,
+            r#"
+fn main() {
+    let x = Ok(1);
+    if let Ok(_tmp) = x {}
+}
+"#,
+        );
+    }
+
+    #[test]
+    fn replace_is_ok_with_if_let_ok_not_applicable() {
+        check_assist_not_applicable(
+            replace_is_method_with_if_let_method,
+            r#"
+fn main() {
+    let x = Ok(1);
+    if x.is_e$0rr() {}
+}
+"#,
+        );
+    }
+}

Diff for: crates/ide-assists/src/handlers/replace_is_some_with_if_let_some.rs

@@ -195,6 +195,7 @@ mod handlers {
     mod replace_try_expr_with_match;
     mod replace_derive_with_manual_impl;
     mod replace_if_let_with_match;
+    mod replace_is_method_with_if_let_method;
     mod replace_method_eager_lazy;
     mod replace_arith_op;
     mod introduce_named_generic;
@@ -213,7 +214,6 @@ mod handlers {
     mod unwrap_block;
     mod unwrap_result_return_type;
     mod unqualify_method_call;
-    mod replace_is_some_with_if_let_some;
     mod wrap_return_type_in_result;
     mod into_to_qualified_from;
 
@@ -314,6 +314,7 @@ mod handlers {
             replace_derive_with_manual_impl::replace_derive_with_manual_impl,
             replace_if_let_with_match::replace_if_let_with_match,
             replace_if_let_with_match::replace_match_with_if_let,
+            replace_is_method_with_if_let_method::replace_is_method_with_if_let_method,
             replace_let_with_if_let::replace_let_with_if_let,
             replace_method_eager_lazy::replace_with_eager_method,
             replace_method_eager_lazy::replace_with_lazy_method,
@@ -333,7 +334,6 @@ mod handlers {
             unwrap_result_return_type::unwrap_result_return_type,
             unwrap_tuple::unwrap_tuple,
             unqualify_method_call::unqualify_method_call,
-            replace_is_some_with_if_let_some::replace_is_some_with_if_let_some,
             wrap_return_type_in_result::wrap_return_type_in_result,
             // These are manually sorted for better priorities. By default,
             // priority is determined by the size of the target range (smaller