1 files changed, 56 insertions, 0 deletions

diff --git a/crates/ra_ide_api/src/extend_selection.rs b/crates/ra_ide_api/src/extend_selection.rs
new file mode 100644
index 000000000..c3c809c9f
--- /dev/null
+++ b/crates/ra_ide_api/src/extend_selection.rs
@@ -0,0 +1,56 @@
+use ra_db::SyntaxDatabase;
+use ra_syntax::{
+    SyntaxNode, AstNode, SourceFile,
+    ast, algo::find_covering_node,
+};
+
+use crate::{
+    TextRange, FileRange,
+    db::RootDatabase,
+};
+
+pub(crate) fn extend_selection(db: &RootDatabase, frange: FileRange) -> TextRange {
+    let source_file = db.source_file(frange.file_id);
+    if let Some(range) = extend_selection_in_macro(db, &source_file, frange) {
+        return range;
+    }
+    ra_ide_api_light::extend_selection(source_file.syntax(), frange.range).unwrap_or(frange.range)
+}
+
+fn extend_selection_in_macro(
+    _db: &RootDatabase,
+    source_file: &SourceFile,
+    frange: FileRange,
+) -> Option<TextRange> {
+    let macro_call = find_macro_call(source_file.syntax(), frange.range)?;
+    let (off, exp) = hir::MacroDef::ast_expand(macro_call)?;
+    let dst_range = exp.map_range_forward(frange.range - off)?;
+    let dst_range = ra_ide_api_light::extend_selection(&exp.syntax(), dst_range)?;
+    let src_range = exp.map_range_back(dst_range)? + off;
+    Some(src_range)
+}
+
+fn find_macro_call(node: &SyntaxNode, range: TextRange) -> Option<&ast::MacroCall> {
+    find_covering_node(node, range)
+        .ancestors()
+        .find_map(ast::MacroCall::cast)
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mock_analysis::single_file_with_range;
+    use test_utils::assert_eq_dbg;
+
+    #[test]
+    fn extend_selection_inside_macros() {
+        let (analysis, frange) = single_file_with_range(
+            "
+            fn main() {
+                ctry!(foo(|x| <|>x<|>));
+            }
+        ",
+        );
+        let r = analysis.extend_selection(frange);
+        assert_eq_dbg("[51; 56)", &r);
+    }
+}