split import assist

2 files changed, 47 insertions, 0 deletions

diff --git a/crates/ra_editor/src/assists.rs b/crates/ra_editor/src/assists.rs
index cc40ee4c8..57b78342a 100644
--- a/crates/ra_editor/src/assists.rs
+++ b/crates/ra_editor/src/assists.rs
@@ -8,6 +8,7 @@ mod add_derive;
 mod add_impl;
 mod introduce_variable;
 mod change_visibility;
+mod split_import;
 
 use ra_text_edit::{TextEdit, TextEditBuilder};
 use ra_syntax::{
@@ -23,6 +24,7 @@ pub use self::{
     add_impl::add_impl,
     introduce_variable::introduce_variable,
     change_visibility::change_visibility,
+    split_import::split_import,
 };
 
 /// Return all the assists applicable at the given position.
@@ -34,6 +36,7 @@ pub fn assists(file: &SourceFileNode, range: TextRange) -> Vec<LocalEdit> {
         add_impl,
         introduce_variable,
         change_visibility,
+        split_import,
     ]
     .iter()
     .filter_map(|&assist| ctx.clone().apply(assist))
diff --git a/crates/ra_editor/src/assists/split_import.rs b/crates/ra_editor/src/assists/split_import.rs
new file mode 100644
index 000000000..75f9e8dfb
--- /dev/null
+++ b/crates/ra_editor/src/assists/split_import.rs
@@ -0,0 +1,44 @@
+use ra_syntax::{
+    TextUnit, AstNode, SyntaxKind::COLONCOLON,
+    ast,
+    algo::generate,
+};
+
+use crate::assists::{AssistCtx, Assist};
+
+pub fn split_import(ctx: AssistCtx) -> Option<Assist> {
+    let colon_colon = ctx
+        .leaf_at_offset()
+        .find(|leaf| leaf.kind() == COLONCOLON)?;
+    let path = colon_colon.parent().and_then(ast::Path::cast)?;
+    let top_path = generate(Some(path), |it| it.parent_path()).last()?;
+
+    let use_tree = top_path.syntax().ancestors().find_map(ast::UseTree::cast);
+    if use_tree.is_none() {
+        return None;
+    }
+
+    let l_curly = colon_colon.range().end();
+    let r_curly = top_path.syntax().range().end();
+
+    ctx.build("split import", |edit| {
+        edit.insert(l_curly, "{");
+        edit.insert(r_curly, "}");
+        edit.set_cursor(l_curly + TextUnit::of_str("{"));
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::assists::check_assist;
+
+    #[test]
+    fn test_split_import() {
+        check_assist(
+            split_import,
+            "use crate::<|>db::RootDatabase;",
+            "use crate::{<|>db::RootDatabase};",
+        )
+    }
+}