Merge #7572

7572: Add `find_or_create_impl_block` to assist utils r=matklad a=yoshuawuyts

This is another continuation of https://github.com/rust-analyzer/rust-analyzer/pull/7562, introducing a small util to either find an `impl` block, or create a new one if none exists. I copied this code from the `generate_new` assist into https://github.com/rust-analyzer/rust-analyzer/pull/7562, and this unifies both into a helper.

It doesn't feel super polished in its current state, but my hope is that this is enough of a starting point that it can be expanded on later. For example something that would be useful would be a flag which either returns the index of the start of the block, or the end of the block.

Anyway, I hope this is useful. Thanks!

Co-authored-by: Yoshua Wuyts <[email protected]>

1 files changed, 6 insertions, 14 deletions

diff --git a/crates/assists/src/handlers/generate_enum_match_method.rs b/crates/assists/src/handlers/generate_enum_match_method.rs
index ee89d4208..4cf66b5d5 100644
--- a/crates/assists/src/handlers/generate_enum_match_method.rs
+++ b/crates/assists/src/handlers/generate_enum_match_method.rs
@@ -1,9 +1,12 @@
 use stdx::{format_to, to_lower_snake_case};
+use syntax::ast::VisibilityOwner;
 use syntax::ast::{self, AstNode, NameOwner};
-use syntax::{ast::VisibilityOwner, T};
 use test_utils::mark;
 
-use crate::{utils::find_struct_impl, AssistContext, AssistId, AssistKind, Assists};
+use crate::{
+    utils::{find_impl_block, find_struct_impl},
+    AssistContext, AssistId, AssistKind, Assists,
+};
 
 // Assist: generate_enum_match_method
 //
@@ -63,7 +66,6 @@ pub(crate) fn generate_enum_match_method(acc: &mut Assists, ctx: &AssistContext)
             }
 
             let vis = parent_enum.visibility().map_or(String::new(), |v| format!("{} ", v));
-
             format_to!(
                 buf,
                 "    /// Returns `true` if the {} is [`{}`].
@@ -78,17 +80,7 @@ pub(crate) fn generate_enum_match_method(acc: &mut Assists, ctx: &AssistContext)
             );
 
             let start_offset = impl_def
-                .and_then(|impl_def| {
-                    buf.push('\n');
-                    let start = impl_def
-                        .syntax()
-                        .descendants_with_tokens()
-                        .find(|t| t.kind() == T!['{'])?
-                        .text_range()
-                        .end();
-
-                    Some(start)
-                })
+                .and_then(|impl_def| find_impl_block(impl_def, &mut buf))
                 .unwrap_or_else(|| {
                     buf = generate_impl_text(&parent_enum, &buf);
                     parent_enum.syntax().text_range().end()