bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-assists/src/handlers/generate_derive.rs')
-rw-r--r--crates/ide-assists/src/handlers/generate_derive.rs132
1 files changed, 132 insertions, 0 deletions
diff --git a/crates/ide-assists/src/handlers/generate_derive.rs b/crates/ide-assists/src/handlers/generate_derive.rs
new file mode 100644
index 0000000000..28483f795e
--- /dev/null
+++ b/crates/ide-assists/src/handlers/generate_derive.rs
@@ -0,0 +1,132 @@
+use syntax::{
+ ast::{self, AstNode, HasAttrs},
+ SyntaxKind::{COMMENT, WHITESPACE},
+ TextSize,
+};
+
+use crate::{AssistContext, AssistId, AssistKind, Assists};
+
+// Assist: generate_derive
+//
+// Adds a new `#[derive()]` clause to a struct or enum.
+//
+// ```
+// struct Point {
+// x: u32,
+// y: u32,$0
+// }
+// ```
+// ->
+// ```
+// #[derive($0)]
+// struct Point {
+// x: u32,
+// y: u32,
+// }
+// ```
+pub(crate) fn generate_derive(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
+ let cap = ctx.config.snippet_cap?;
+ let nominal = ctx.find_node_at_offset::<ast::Adt>()?;
+ let node_start = derive_insertion_offset(&nominal)?;
+ let target = nominal.syntax().text_range();
+ acc.add(
+ AssistId("generate_derive", AssistKind::Generate),
+ "Add `#[derive]`",
+ target,
+ |builder| {
+ let derive_attr = nominal
+ .attrs()
+ .filter_map(|x| x.as_simple_call())
+ .filter(|(name, _arg)| name == "derive")
+ .map(|(_name, arg)| arg)
+ .next();
+ match derive_attr {
+ None => {
+ builder.insert_snippet(cap, node_start, "#[derive($0)]\n");
+ }
+ Some(tt) => {
+ // Just move the cursor.
+ builder.insert_snippet(
+ cap,
+ tt.syntax().text_range().end() - TextSize::of(')'),
+ "$0",
+ )
+ }
+ };
+ },
+ )
+}
+
+// Insert `derive` after doc comments.
+fn derive_insertion_offset(nominal: &ast::Adt) -> Option<TextSize> {
+ let non_ws_child = nominal
+ .syntax()
+ .children_with_tokens()
+ .find(|it| it.kind() != COMMENT && it.kind() != WHITESPACE)?;
+ Some(non_ws_child.text_range().start())
+}
+
+#[cfg(test)]
+mod tests {
+ use crate::tests::{check_assist, check_assist_target};
+
+ use super::*;
+
+ #[test]
+ fn add_derive_new() {
+ check_assist(
+ generate_derive,
+ "struct Foo { a: i32, $0}",
+ "#[derive($0)]\nstruct Foo { a: i32, }",
+ );
+ check_assist(
+ generate_derive,
+ "struct Foo { $0 a: i32, }",
+ "#[derive($0)]\nstruct Foo { a: i32, }",
+ );
+ }
+
+ #[test]
+ fn add_derive_existing() {
+ check_assist(
+ generate_derive,
+ "#[derive(Clone)]\nstruct Foo { a: i32$0, }",
+ "#[derive(Clone$0)]\nstruct Foo { a: i32, }",
+ );
+ }
+
+ #[test]
+ fn add_derive_new_with_doc_comment() {
+ check_assist(
+ generate_derive,
+ "
+/// `Foo` is a pretty important struct.
+/// It does stuff.
+struct Foo { a: i32$0, }
+ ",
+ "
+/// `Foo` is a pretty important struct.
+/// It does stuff.
+#[derive($0)]
+struct Foo { a: i32, }
+ ",
+ );
+ }
+
+ #[test]
+ fn add_derive_target() {
+ check_assist_target(
+ generate_derive,
+ "
+struct SomeThingIrrelevant;
+/// `Foo` is a pretty important struct.
+/// It does stuff.
+struct Foo { a: i32$0, }
+struct EvenMoreIrrelevant;
+ ",
+ "/// `Foo` is a pretty important struct.
+/// It does stuff.
+struct Foo { a: i32, }",
+ );
+ }
+}