1 files changed, 654 insertions, 0 deletions

diff --git a/crates/ide/src/extend_selection.rs b/crates/ide/src/extend_selection.rs
new file mode 100644
index 000000000..34563a026
--- /dev/null
+++ b/crates/ide/src/extend_selection.rs
@@ -0,0 +1,654 @@
+use std::iter::successors;
+
+use hir::Semantics;
+use ide_db::RootDatabase;
+use syntax::{
+    algo::{self, find_covering_element, skip_trivia_token},
+    ast::{self, AstNode, AstToken},
+    Direction, NodeOrToken,
+    SyntaxKind::{self, *},
+    SyntaxNode, SyntaxToken, TextRange, TextSize, TokenAtOffset, T,
+};
+
+use crate::FileRange;
+
+// Feature: Extend Selection
+//
+// Extends the current selection to the encompassing syntactic construct
+// (expression, statement, item, module, etc). It works with multiple cursors.
+//
+// |===
+// | Editor  | Shortcut
+//
+// | VS Code | kbd:[Ctrl+Shift+→]
+// |===
+pub(crate) fn extend_selection(db: &RootDatabase, frange: FileRange) -> TextRange {
+    let sema = Semantics::new(db);
+    let src = sema.parse(frange.file_id);
+    try_extend_selection(&sema, src.syntax(), frange).unwrap_or(frange.range)
+}
+
+fn try_extend_selection(
+    sema: &Semantics<RootDatabase>,
+    root: &SyntaxNode,
+    frange: FileRange,
+) -> Option<TextRange> {
+    let range = frange.range;
+
+    let string_kinds = [COMMENT, STRING, RAW_STRING, BYTE_STRING, RAW_BYTE_STRING];
+    let list_kinds = [
+        RECORD_PAT_FIELD_LIST,
+        MATCH_ARM_LIST,
+        RECORD_FIELD_LIST,
+        TUPLE_FIELD_LIST,
+        RECORD_EXPR_FIELD_LIST,
+        VARIANT_LIST,
+        USE_TREE_LIST,
+        GENERIC_PARAM_LIST,
+        GENERIC_ARG_LIST,
+        TYPE_BOUND_LIST,
+        PARAM_LIST,
+        ARG_LIST,
+        ARRAY_EXPR,
+        TUPLE_EXPR,
+        TUPLE_TYPE,
+        TUPLE_PAT,
+        WHERE_CLAUSE,
+    ];
+
+    if range.is_empty() {
+        let offset = range.start();
+        let mut leaves = root.token_at_offset(offset);
+        if leaves.clone().all(|it| it.kind() == WHITESPACE) {
+            return Some(extend_ws(root, leaves.next()?, offset));
+        }
+        let leaf_range = match leaves {
+            TokenAtOffset::None => return None,
+            TokenAtOffset::Single(l) => {
+                if string_kinds.contains(&l.kind()) {
+                    extend_single_word_in_comment_or_string(&l, offset)
+                        .unwrap_or_else(|| l.text_range())
+                } else {
+                    l.text_range()
+                }
+            }
+            TokenAtOffset::Between(l, r) => pick_best(l, r).text_range(),
+        };
+        return Some(leaf_range);
+    };
+    let node = match find_covering_element(root, range) {
+        NodeOrToken::Token(token) => {
+            if token.text_range() != range {
+                return Some(token.text_range());
+            }
+            if let Some(comment) = ast::Comment::cast(token.clone()) {
+                if let Some(range) = extend_comments(comment) {
+                    return Some(range);
+                }
+            }
+            token.parent()
+        }
+        NodeOrToken::Node(node) => node,
+    };
+
+    // if we are in single token_tree, we maybe live in macro or attr
+    if node.kind() == TOKEN_TREE {
+        if let Some(macro_call) = node.ancestors().find_map(ast::MacroCall::cast) {
+            if let Some(range) = extend_tokens_from_range(sema, macro_call, range) {
+                return Some(range);
+            }
+        }
+    }
+
+    if node.text_range() != range {
+        return Some(node.text_range());
+    }
+
+    let node = shallowest_node(&node);
+
+    if node.parent().map(|n| list_kinds.contains(&n.kind())) == Some(true) {
+        if let Some(range) = extend_list_item(&node) {
+            return Some(range);
+        }
+    }
+
+    node.parent().map(|it| it.text_range())
+}
+
+fn extend_tokens_from_range(
+    sema: &Semantics<RootDatabase>,
+    macro_call: ast::MacroCall,
+    original_range: TextRange,
+) -> Option<TextRange> {
+    let src = find_covering_element(&macro_call.syntax(), original_range);
+    let (first_token, last_token) = match src {
+        NodeOrToken::Node(it) => (it.first_token()?, it.last_token()?),
+        NodeOrToken::Token(it) => (it.clone(), it),
+    };
+
+    let mut first_token = skip_trivia_token(first_token, Direction::Next)?;
+    let mut last_token = skip_trivia_token(last_token, Direction::Prev)?;
+
+    while !original_range.contains_range(first_token.text_range()) {
+        first_token = skip_trivia_token(first_token.next_token()?, Direction::Next)?;
+    }
+    while !original_range.contains_range(last_token.text_range()) {
+        last_token = skip_trivia_token(last_token.prev_token()?, Direction::Prev)?;
+    }
+
+    // compute original mapped token range
+    let extended = {
+        let fst_expanded = sema.descend_into_macros(first_token.clone());
+        let lst_expanded = sema.descend_into_macros(last_token.clone());
+        let mut lca = algo::least_common_ancestor(&fst_expanded.parent(), &lst_expanded.parent())?;
+        lca = shallowest_node(&lca);
+        if lca.first_token() == Some(fst_expanded) && lca.last_token() == Some(lst_expanded) {
+            lca = lca.parent()?;
+        }
+        lca
+    };
+
+    // Compute parent node range
+    let validate = |token: &SyntaxToken| {
+        let expanded = sema.descend_into_macros(token.clone());
+        algo::least_common_ancestor(&extended, &expanded.parent()).as_ref() == Some(&extended)
+    };
+
+    // Find the first and last text range under expanded parent
+    let first = successors(Some(first_token), |token| {
+        let token = token.prev_token()?;
+        skip_trivia_token(token, Direction::Prev)
+    })
+    .take_while(validate)
+    .last()?;
+
+    let last = successors(Some(last_token), |token| {
+        let token = token.next_token()?;
+        skip_trivia_token(token, Direction::Next)
+    })
+    .take_while(validate)
+    .last()?;
+
+    let range = first.text_range().cover(last.text_range());
+    if range.contains_range(original_range) && original_range != range {
+        Some(range)
+    } else {
+        None
+    }
+}
+
+/// Find the shallowest node with same range, which allows us to traverse siblings.
+fn shallowest_node(node: &SyntaxNode) -> SyntaxNode {
+    node.ancestors().take_while(|n| n.text_range() == node.text_range()).last().unwrap()
+}
+
+fn extend_single_word_in_comment_or_string(
+    leaf: &SyntaxToken,
+    offset: TextSize,
+) -> Option<TextRange> {
+    let text: &str = leaf.text();
+    let cursor_position: u32 = (offset - leaf.text_range().start()).into();
+
+    let (before, after) = text.split_at(cursor_position as usize);
+
+    fn non_word_char(c: char) -> bool {
+        !(c.is_alphanumeric() || c == '_')
+    }
+
+    let start_idx = before.rfind(non_word_char)? as u32;
+    let end_idx = after.find(non_word_char).unwrap_or_else(|| after.len()) as u32;
+
+    let from: TextSize = (start_idx + 1).into();
+    let to: TextSize = (cursor_position + end_idx).into();
+
+    let range = TextRange::new(from, to);
+    if range.is_empty() {
+        None
+    } else {
+        Some(range + leaf.text_range().start())
+    }
+}
+
+fn extend_ws(root: &SyntaxNode, ws: SyntaxToken, offset: TextSize) -> TextRange {
+    let ws_text = ws.text();
+    let suffix = TextRange::new(offset, ws.text_range().end()) - ws.text_range().start();
+    let prefix = TextRange::new(ws.text_range().start(), offset) - ws.text_range().start();
+    let ws_suffix = &ws_text.as_str()[suffix];
+    let ws_prefix = &ws_text.as_str()[prefix];
+    if ws_text.contains('\n') && !ws_suffix.contains('\n') {
+        if let Some(node) = ws.next_sibling_or_token() {
+            let start = match ws_prefix.rfind('\n') {
+                Some(idx) => ws.text_range().start() + TextSize::from((idx + 1) as u32),
+                None => node.text_range().start(),
+            };
+            let end = if root.text().char_at(node.text_range().end()) == Some('\n') {
+                node.text_range().end() + TextSize::of('\n')
+            } else {
+                node.text_range().end()
+            };
+            return TextRange::new(start, end);
+        }
+    }
+    ws.text_range()
+}
+
+fn pick_best(l: SyntaxToken, r: SyntaxToken) -> SyntaxToken {
+    return if priority(&r) > priority(&l) { r } else { l };
+    fn priority(n: &SyntaxToken) -> usize {
+        match n.kind() {
+            WHITESPACE => 0,
+            IDENT | T![self] | T![super] | T![crate] | LIFETIME => 2,
+            _ => 1,
+        }
+    }
+}
+
+/// Extend list item selection to include nearby delimiter and whitespace.
+fn extend_list_item(node: &SyntaxNode) -> Option<TextRange> {
+    fn is_single_line_ws(node: &SyntaxToken) -> bool {
+        node.kind() == WHITESPACE && !node.text().contains('\n')
+    }
+
+    fn nearby_delimiter(
+        delimiter_kind: SyntaxKind,
+        node: &SyntaxNode,
+        dir: Direction,
+    ) -> Option<SyntaxToken> {
+        node.siblings_with_tokens(dir)
+            .skip(1)
+            .skip_while(|node| match node {
+                NodeOrToken::Node(_) => false,
+                NodeOrToken::Token(it) => is_single_line_ws(it),
+            })
+            .next()
+            .and_then(|it| it.into_token())
+            .filter(|node| node.kind() == delimiter_kind)
+    }
+
+    let delimiter = match node.kind() {
+        TYPE_BOUND => T![+],
+        _ => T![,],
+    };
+
+    if let Some(delimiter_node) = nearby_delimiter(delimiter, node, Direction::Next) {
+        // Include any following whitespace when delimiter is after list item.
+        let final_node = delimiter_node
+            .next_sibling_or_token()
+            .and_then(|it| it.into_token())
+            .filter(|node| is_single_line_ws(node))
+            .unwrap_or(delimiter_node);
+
+        return Some(TextRange::new(node.text_range().start(), final_node.text_range().end()));
+    }
+    if let Some(delimiter_node) = nearby_delimiter(delimiter, node, Direction::Prev) {
+        return Some(TextRange::new(delimiter_node.text_range().start(), node.text_range().end()));
+    }
+
+    None
+}
+
+fn extend_comments(comment: ast::Comment) -> Option<TextRange> {
+    let prev = adj_comments(&comment, Direction::Prev);
+    let next = adj_comments(&comment, Direction::Next);
+    if prev != next {
+        Some(TextRange::new(prev.syntax().text_range().start(), next.syntax().text_range().end()))
+    } else {
+        None
+    }
+}
+
+fn adj_comments(comment: &ast::Comment, dir: Direction) -> ast::Comment {
+    let mut res = comment.clone();
+    for element in comment.syntax().siblings_with_tokens(dir) {
+        let token = match element.as_token() {
+            None => break,
+            Some(token) => token,
+        };
+        if let Some(c) = ast::Comment::cast(token.clone()) {
+            res = c
+        } else if token.kind() != WHITESPACE || token.text().contains("\n\n") {
+            break;
+        }
+    }
+    res
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::mock_analysis::analysis_and_position;
+
+    use super::*;
+
+    fn do_check(before: &str, afters: &[&str]) {
+        let (analysis, position) = analysis_and_position(&before);
+        let before = analysis.file_text(position.file_id).unwrap();
+        let range = TextRange::empty(position.offset);
+        let mut frange = FileRange { file_id: position.file_id, range };
+
+        for &after in afters {
+            frange.range = analysis.extend_selection(frange).unwrap();
+            let actual = &before[frange.range];
+            assert_eq!(after, actual);
+        }
+    }
+
+    #[test]
+    fn test_extend_selection_arith() {
+        do_check(r#"fn foo() { <|>1 + 1 }"#, &["1", "1 + 1", "{ 1 + 1 }"]);
+    }
+
+    #[test]
+    fn test_extend_selection_list() {
+        do_check(r#"fn foo(<|>x: i32) {}"#, &["x", "x: i32"]);
+        do_check(r#"fn foo(<|>x: i32, y: i32) {}"#, &["x", "x: i32", "x: i32, "]);
+        do_check(r#"fn foo(<|>x: i32,y: i32) {}"#, &["x", "x: i32", "x: i32,", "(x: i32,y: i32)"]);
+        do_check(r#"fn foo(x: i32, <|>y: i32) {}"#, &["y", "y: i32", ", y: i32"]);
+        do_check(r#"fn foo(x: i32, <|>y: i32, ) {}"#, &["y", "y: i32", "y: i32, "]);
+        do_check(r#"fn foo(x: i32,<|>y: i32) {}"#, &["y", "y: i32", ",y: i32"]);
+
+        do_check(r#"const FOO: [usize; 2] = [ 22<|> , 33];"#, &["22", "22 , "]);
+        do_check(r#"const FOO: [usize; 2] = [ 22 , 33<|>];"#, &["33", ", 33"]);
+        do_check(r#"const FOO: [usize; 2] = [ 22 , 33<|> ,];"#, &["33", "33 ,", "[ 22 , 33 ,]"]);
+
+        do_check(r#"fn main() { (1, 2<|>) }"#, &["2", ", 2", "(1, 2)"]);
+
+        do_check(
+            r#"
+const FOO: [usize; 2] = [
+    22,
+    <|>33,
+]"#,
+            &["33", "33,"],
+        );
+
+        do_check(
+            r#"
+const FOO: [usize; 2] = [
+    22
+    , 33<|>,
+]"#,
+            &["33", "33,"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_start_of_the_line() {
+        do_check(
+            r#"
+impl S {
+<|>    fn foo() {
+
+    }
+}"#,
+            &["    fn foo() {\n\n    }\n"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_doc_comments() {
+        do_check(
+            r#"
+struct A;
+
+/// bla
+/// bla
+struct B {
+    <|>
+}
+            "#,
+            &["\n    \n", "{\n    \n}", "/// bla\n/// bla\nstruct B {\n    \n}"],
+        )
+    }
+
+    #[test]
+    fn test_extend_selection_comments() {
+        do_check(
+            r#"
+fn bar(){}
+
+// fn foo() {
+// 1 + <|>1
+// }
+
+// fn foo(){}
+    "#,
+            &["1", "// 1 + 1", "// fn foo() {\n// 1 + 1\n// }"],
+        );
+
+        do_check(
+            r#"
+// #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+// pub enum Direction {
+//  <|>   Next,
+//     Prev
+// }
+"#,
+            &[
+                "//     Next,",
+                "// #[derive(Debug, Clone, Copy, PartialEq, Eq)]\n// pub enum Direction {\n//     Next,\n//     Prev\n// }",
+            ],
+        );
+
+        do_check(
+            r#"
+/*
+foo
+_bar1<|>*/
+"#,
+            &["_bar1", "/*\nfoo\n_bar1*/"],
+        );
+
+        do_check(r#"//!<|>foo_2 bar"#, &["foo_2", "//!foo_2 bar"]);
+
+        do_check(r#"/<|>/foo bar"#, &["//foo bar"]);
+    }
+
+    #[test]
+    fn test_extend_selection_prefer_idents() {
+        do_check(
+            r#"
+fn main() { foo<|>+bar;}
+"#,
+            &["foo", "foo+bar"],
+        );
+        do_check(
+            r#"
+fn main() { foo+<|>bar;}
+"#,
+            &["bar", "foo+bar"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_prefer_lifetimes() {
+        do_check(r#"fn foo<<|>'a>() {}"#, &["'a", "<'a>"]);
+        do_check(r#"fn foo<'a<|>>() {}"#, &["'a", "<'a>"]);
+    }
+
+    #[test]
+    fn test_extend_selection_select_first_word() {
+        do_check(r#"// foo bar b<|>az quxx"#, &["baz", "// foo bar baz quxx"]);
+        do_check(
+            r#"
+impl S {
+fn foo() {
+// hel<|>lo world
+}
+}
+"#,
+            &["hello", "// hello world"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_string() {
+        do_check(
+            r#"
+fn bar(){}
+
+" fn f<|>oo() {"
+"#,
+            &["foo", "\" fn foo() {\""],
+        );
+    }
+
+    #[test]
+    fn test_extend_trait_bounds_list_in_where_clause() {
+        do_check(
+            r#"
+fn foo<R>()
+    where
+        R: req::Request + 'static,
+        R::Params: DeserializeOwned<|> + panic::UnwindSafe + 'static,
+        R::Result: Serialize + 'static,
+"#,
+            &[
+                "DeserializeOwned",
+                "DeserializeOwned + ",
+                "DeserializeOwned + panic::UnwindSafe + 'static",
+                "R::Params: DeserializeOwned + panic::UnwindSafe + 'static",
+                "R::Params: DeserializeOwned + panic::UnwindSafe + 'static,",
+            ],
+        );
+        do_check(r#"fn foo<T>() where T: <|>Copy"#, &["Copy"]);
+        do_check(r#"fn foo<T>() where T: <|>Copy + Display"#, &["Copy", "Copy + "]);
+        do_check(r#"fn foo<T>() where T: <|>Copy +Display"#, &["Copy", "Copy +"]);
+        do_check(r#"fn foo<T>() where T: <|>Copy+Display"#, &["Copy", "Copy+"]);
+        do_check(r#"fn foo<T>() where T: Copy + <|>Display"#, &["Display", "+ Display"]);
+        do_check(r#"fn foo<T>() where T: Copy + <|>Display + Sync"#, &["Display", "Display + "]);
+        do_check(r#"fn foo<T>() where T: Copy +<|>Display"#, &["Display", "+Display"]);
+    }
+
+    #[test]
+    fn test_extend_trait_bounds_list_inline() {
+        do_check(r#"fn foo<T: <|>Copy>() {}"#, &["Copy"]);
+        do_check(r#"fn foo<T: <|>Copy + Display>() {}"#, &["Copy", "Copy + "]);
+        do_check(r#"fn foo<T: <|>Copy +Display>() {}"#, &["Copy", "Copy +"]);
+        do_check(r#"fn foo<T: <|>Copy+Display>() {}"#, &["Copy", "Copy+"]);
+        do_check(r#"fn foo<T: Copy + <|>Display>() {}"#, &["Display", "+ Display"]);
+        do_check(r#"fn foo<T: Copy + <|>Display + Sync>() {}"#, &["Display", "Display + "]);
+        do_check(r#"fn foo<T: Copy +<|>Display>() {}"#, &["Display", "+Display"]);
+        do_check(
+            r#"fn foo<T: Copy<|> + Display, U: Copy>() {}"#,
+            &[
+                "Copy",
+                "Copy + ",
+                "Copy + Display",
+                "T: Copy + Display",
+                "T: Copy + Display, ",
+                "<T: Copy + Display, U: Copy>",
+            ],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_on_tuple_in_type() {
+        do_check(
+            r#"fn main() { let _: (krate, <|>_crate_def_map, module_id) = (); }"#,
+            &["_crate_def_map", "_crate_def_map, ", "(krate, _crate_def_map, module_id)"],
+        );
+        // white space variations
+        do_check(
+            r#"fn main() { let _: (krate,<|>_crate_def_map,module_id) = (); }"#,
+            &["_crate_def_map", "_crate_def_map,", "(krate,_crate_def_map,module_id)"],
+        );
+        do_check(
+            r#"
+fn main() { let _: (
+    krate,
+    _crate<|>_def_map,
+    module_id
+) = (); }"#,
+            &[
+                "_crate_def_map",
+                "_crate_def_map,",
+                "(\n    krate,\n    _crate_def_map,\n    module_id\n)",
+            ],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_on_tuple_in_rvalue() {
+        do_check(
+            r#"fn main() { let var = (krate, _crate_def_map<|>, module_id); }"#,
+            &["_crate_def_map", "_crate_def_map, ", "(krate, _crate_def_map, module_id)"],
+        );
+        // white space variations
+        do_check(
+            r#"fn main() { let var = (krate,_crate<|>_def_map,module_id); }"#,
+            &["_crate_def_map", "_crate_def_map,", "(krate,_crate_def_map,module_id)"],
+        );
+        do_check(
+            r#"
+fn main() { let var = (
+    krate,
+    _crate_def_map<|>,
+    module_id
+); }"#,
+            &[
+                "_crate_def_map",
+                "_crate_def_map,",
+                "(\n    krate,\n    _crate_def_map,\n    module_id\n)",
+            ],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_on_tuple_pat() {
+        do_check(
+            r#"fn main() { let (krate, _crate_def_map<|>, module_id) = var; }"#,
+            &["_crate_def_map", "_crate_def_map, ", "(krate, _crate_def_map, module_id)"],
+        );
+        // white space variations
+        do_check(
+            r#"fn main() { let (krate,_crate<|>_def_map,module_id) = var; }"#,
+            &["_crate_def_map", "_crate_def_map,", "(krate,_crate_def_map,module_id)"],
+        );
+        do_check(
+            r#"
+fn main() { let (
+    krate,
+    _crate_def_map<|>,
+    module_id
+) = var; }"#,
+            &[
+                "_crate_def_map",
+                "_crate_def_map,",
+                "(\n    krate,\n    _crate_def_map,\n    module_id\n)",
+            ],
+        );
+    }
+
+    #[test]
+    fn extend_selection_inside_macros() {
+        do_check(
+            r#"macro_rules! foo { ($item:item) => {$item} }
+                foo!{fn hello(na<|>me:usize){}}"#,
+            &[
+                "name",
+                "name:usize",
+                "(name:usize)",
+                "fn hello(name:usize){}",
+                "{fn hello(name:usize){}}",
+                "foo!{fn hello(name:usize){}}",
+            ],
+        );
+    }
+
+    #[test]
+    fn extend_selection_inside_recur_macros() {
+        do_check(
+            r#" macro_rules! foo2 { ($item:item) => {$item} }
+                macro_rules! foo { ($item:item) => {foo2!($item);} }
+                foo!{fn hello(na<|>me:usize){}}"#,
+            &[
+                "name",
+                "name:usize",
+                "(name:usize)",
+                "fn hello(name:usize){}",
+                "{fn hello(name:usize){}}",
+                "foo!{fn hello(name:usize){}}",
+            ],
+        );
+    }
+}