4 files changed, 13 insertions, 15 deletions

diff --git a/crates/ra_assists/src/flip_comma.rs b/crates/ra_assists/src/flip_comma.rs
index 08644d720..0d4a789fc 100644
--- a/crates/ra_assists/src/flip_comma.rs
+++ b/crates/ra_assists/src/flip_comma.rs
@@ -2,9 +2,10 @@ use hir::db::HirDatabase;
 use ra_syntax::{
     Direction,
     SyntaxKind::COMMA,
+    algo::non_trivia_sibling,
 };
 
-use crate::{AssistCtx, Assist, non_trivia_sibling};
+use crate::{AssistCtx, Assist};
 
 pub(crate) fn flip_comma(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
     let comma = ctx.leaf_at_offset().find(|leaf| leaf.kind() == COMMA)?;
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index 7bd9b5ae6..e1e899edc 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -10,7 +10,7 @@ mod assist_ctx;
 use itertools::Itertools;
 
 use ra_text_edit::TextEdit;
-use ra_syntax::{TextRange, TextUnit, SyntaxNode, Direction};
+use ra_syntax::{TextRange, TextUnit};
 use ra_db::FileRange;
 use hir::db::HirDatabase;
 
@@ -104,10 +104,6 @@ fn all_assists<DB: HirDatabase>() -> &'static [fn(AssistCtx<DB>) -> Option<Assis
     ]
 }
 
-fn non_trivia_sibling(node: &SyntaxNode, direction: Direction) -> Option<&SyntaxNode> {
-    node.siblings(direction).skip(1).find(|node| !node.kind().is_trivia())
-}
-
 #[cfg(test)]
 mod helpers {
     use hir::mock::MockDatabase;
diff --git a/crates/ra_ide_api_light/src/join_lines.rs b/crates/ra_ide_api_light/src/join_lines.rs
index 9a400199f..b5bcd62fb 100644
--- a/crates/ra_ide_api_light/src/join_lines.rs
+++ b/crates/ra_ide_api_light/src/join_lines.rs
@@ -2,8 +2,9 @@ use itertools::Itertools;
 use ra_syntax::{
     SourceFile, TextRange, TextUnit, AstNode, SyntaxNode,
     SyntaxKind::{self, WHITESPACE, COMMA, R_CURLY, R_PAREN, R_BRACK},
-    algo::find_covering_node,
+    algo::{find_covering_node, non_trivia_sibling},
     ast,
+    Direction,
 };
 use ra_fmt::{
     compute_ws, extract_trivial_expression
@@ -121,13 +122,8 @@ fn remove_newline(
 }
 
 fn has_comma_after(node: &SyntaxNode) -> bool {
-    let next = node.next_sibling();
-    let nnext = node.next_sibling().and_then(|n| n.next_sibling());
-
-    match (next, nnext) {
-        // Whitespace followed by a comma is fine
-        (Some(ws), Some(comma)) if ws.kind() == WHITESPACE && comma.kind() == COMMA => true,
-        (Some(n), _) => n.kind() == COMMA,
+    match non_trivia_sibling(node, Direction::Next) {
+        Some(n) => n.kind() == COMMA,
         _ => false,
     }
 }
diff --git a/crates/ra_syntax/src/algo.rs b/crates/ra_syntax/src/algo.rs
index e8cf0d4b5..e2b4f0388 100644
--- a/crates/ra_syntax/src/algo.rs
+++ b/crates/ra_syntax/src/algo.rs
@@ -2,7 +2,7 @@ pub mod visit;
 
 use rowan::TransparentNewType;
 
-use crate::{SyntaxNode, TextRange, TextUnit, AstNode};
+use crate::{SyntaxNode, TextRange, TextUnit, AstNode, Direction};
 
 pub use rowan::LeafAtOffset;
 
@@ -29,6 +29,11 @@ pub fn find_node_at_offset<N: AstNode>(syntax: &SyntaxNode, offset: TextUnit) ->
     find_leaf_at_offset(syntax, offset).find_map(|leaf| leaf.ancestors().find_map(N::cast))
 }
 
+/// Finds the first sibling in the given direction which is not `trivia`
+pub fn non_trivia_sibling(node: &SyntaxNode, direction: Direction) -> Option<&SyntaxNode> {
+    node.siblings(direction).skip(1).find(|node| !node.kind().is_trivia())
+}
+
 pub fn find_covering_node(root: &SyntaxNode, range: TextRange) -> &SyntaxNode {
     SyntaxNode::from_repr(root.0.covering_node(range))
 }