4 files changed, 54 insertions, 23 deletions

diff --git a/crates/ra_hir/src/semantics.rs b/crates/ra_hir/src/semantics.rs
index 0b40bf9af..5b0b94e34 100644
--- a/crates/ra_hir/src/semantics.rs
+++ b/crates/ra_hir/src/semantics.rs
@@ -8,8 +8,9 @@ use hir_def::{
 };
 use ra_db::{FileId, FileRange};
 use ra_syntax::{
-    algo::find_covering_element, ast, match_ast, AstNode, NodeOrToken, SyntaxElement, SyntaxNode,
-    SyntaxToken, TextRange, TextUnit,
+    algo::{find_covering_element, skip_trivia_token},
+    ast, match_ast, AstNode, Direction, NodeOrToken, SyntaxElement, SyntaxNode, SyntaxToken,
+    TextRange, TextUnit,
 };
 use rustc_hash::{FxHashMap, FxHashSet};
 
@@ -384,11 +385,12 @@ fn original_range_and_origin(
     };
 
     // the input node has only one token ?
-    let single = node.value.first_token()? == node.value.last_token()?;
+    let single = skip_trivia_token(node.value.first_token()?, Direction::Next)?
+        == skip_trivia_token(node.value.last_token()?, Direction::Prev)?;
 
     return Some(node.value.descendants().find_map(|it| {
-        let first = it.first_token()?;
-        let last = it.last_token()?;
+        let first = skip_trivia_token(it.first_token()?, Direction::Next)?;
+        let last = skip_trivia_token(it.last_token()?, Direction::Prev)?;
 
         if !single && first == last {
             return None;
diff --git a/crates/ra_ide/src/extend_selection.rs b/crates/ra_ide/src/extend_selection.rs
index 86e6f12d7..2e09bd1ec 100644
--- a/crates/ra_ide/src/extend_selection.rs
+++ b/crates/ra_ide/src/extend_selection.rs
@@ -5,7 +5,7 @@ use std::iter::successors;
 use hir::Semantics;
 use ra_ide_db::RootDatabase;
 use ra_syntax::{
-    algo::{self, find_covering_element},
+    algo::{self, find_covering_element, skip_trivia_token},
     ast::{self, AstNode, AstToken},
     Direction, NodeOrToken,
     SyntaxKind::{self, *},
@@ -118,14 +118,14 @@ fn extend_tokens_from_range(
         NodeOrToken::Token(it) => (it.clone(), it),
     };
 
-    let mut first_token = skip_whitespace(first_token, Direction::Next)?;
-    let mut last_token = skip_whitespace(last_token, Direction::Prev)?;
+    let mut first_token = skip_trivia_token(first_token, Direction::Next)?;
+    let mut last_token = skip_trivia_token(last_token, Direction::Prev)?;
 
     while !first_token.text_range().is_subrange(&original_range) {
-        first_token = skip_whitespace(first_token.next_token()?, Direction::Next)?;
+        first_token = skip_trivia_token(first_token.next_token()?, Direction::Next)?;
     }
     while !last_token.text_range().is_subrange(&original_range) {
-        last_token = skip_whitespace(last_token.prev_token()?, Direction::Prev)?;
+        last_token = skip_trivia_token(last_token.prev_token()?, Direction::Prev)?;
     }
 
     // compute original mapped token range
@@ -149,14 +149,14 @@ fn extend_tokens_from_range(
     // Find the first and last text range under expanded parent
     let first = successors(Some(first_token), |token| {
         let token = token.prev_token()?;
-        skip_whitespace(token, Direction::Prev)
+        skip_trivia_token(token, Direction::Prev)
     })
     .take_while(validate)
     .last()?;
 
     let last = successors(Some(last_token), |token| {
         let token = token.next_token()?;
-        skip_whitespace(token, Direction::Next)
+        skip_trivia_token(token, Direction::Next)
     })
     .take_while(validate)
     .last()?;
@@ -169,16 +169,6 @@ fn extend_tokens_from_range(
     }
 }
 
-fn skip_whitespace(mut token: SyntaxToken, direction: Direction) -> Option<SyntaxToken> {
-    while token.kind() == WHITESPACE {
-        token = match direction {
-            Direction::Next => token.next_token()?,
-            Direction::Prev => token.prev_token()?,
-        }
-    }
-    Some(token)
-}
-
 fn union_range(range: TextRange, r: TextRange) -> TextRange {
     let start = range.start().min(r.start());
     let end = range.end().max(r.end());
diff --git a/crates/ra_ide/src/hover.rs b/crates/ra_ide/src/hover.rs
index 29b16e602..177038e20 100644
--- a/crates/ra_ide/src/hover.rs
+++ b/crates/ra_ide/src/hover.rs
@@ -174,6 +174,10 @@ pub(crate) fn hover(db: &RootDatabase, position: FilePosition) -> Option<RangeIn
         .ancestors()
         .find(|n| ast::Expr::cast(n.clone()).is_some() || ast::Pat::cast(n.clone()).is_some())?;
 
+    // FIXME: Currently `hover::typeof` do not work inside
+    // macro expansion such that if the hover range is pointing to
+    // a string literal, the following type_of will return None.
+    // See also `test_hover_through_literal_string_in_macro`
     let frange = sema.original_range(&node);
     res.extend(type_of(db, frange).map(rust_code_markup));
     if res.is_empty() {
@@ -250,6 +254,11 @@ mod tests {
         content[hover.range].to_string()
     }
 
+    fn check_hover_no_result(fixture: &str) {
+        let (analysis, position) = analysis_and_position(fixture);
+        assert!(analysis.hover(position).unwrap().is_none());
+    }
+
     #[test]
     fn hover_shows_type_of_an_expression() {
         let (analysis, position) = single_file_with_position(
@@ -775,6 +784,24 @@ fn func(foo: i32) { if true { <|>foo; }; }
     }
 
     #[test]
+    fn test_hover_through_literal_string_in_macro() {
+        // FIXME: Currently `hover::type_of` do not work inside
+        // macro expansion
+        check_hover_no_result(
+            r#"
+            //- /lib.rs
+            macro_rules! arr {
+                ($($tt:tt)*) => { [$($tt)*)] }
+            }
+            fn foo() {
+                let mastered_for_itunes = "";
+                let _ = arr!("Tr<|>acks", &mastered_for_itunes);
+            }
+            "#,
+        );
+    }
+
+    #[test]
     fn test_hover_non_ascii_space_doc() {
         check_hover_result(
             "
diff --git a/crates/ra_syntax/src/algo.rs b/crates/ra_syntax/src/algo.rs
index f14bcbb35..ebf59288a 100644
--- a/crates/ra_syntax/src/algo.rs
+++ b/crates/ra_syntax/src/algo.rs
@@ -7,7 +7,8 @@ use ra_text_edit::TextEditBuilder;
 use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{
-    AstNode, Direction, NodeOrToken, SyntaxElement, SyntaxNode, SyntaxNodePtr, TextRange, TextUnit,
+    AstNode, Direction, NodeOrToken, SyntaxElement, SyntaxNode, SyntaxNodePtr, SyntaxToken,
+    TextRange, TextUnit,
 };
 
 /// Returns ancestors of the node at the offset, sorted by length. This should
@@ -37,6 +38,17 @@ pub fn find_node_at_offset<N: AstNode>(syntax: &SyntaxNode, offset: TextUnit) ->
     ancestors_at_offset(syntax, offset).find_map(N::cast)
 }
 
+/// Skip to next non `trivia` token
+pub fn skip_trivia_token(mut token: SyntaxToken, direction: Direction) -> Option<SyntaxToken> {
+    while token.kind().is_trivia() {
+        token = match direction {
+            Direction::Next => token.next_token()?,
+            Direction::Prev => token.prev_token()?,
+        }
+    }
+    Some(token)
+}
+
 /// Finds the first sibling in the given direction which is not `trivia`
 pub fn non_trivia_sibling(element: SyntaxElement, direction: Direction) -> Option<SyntaxElement> {
     return match element {