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|
//! FIXME: write short doc here
use std::{
fmt,
hash::BuildHasherDefault,
ops::{self, RangeInclusive},
};
use indexmap::IndexMap;
use itertools::Itertools;
use rustc_hash::FxHashMap;
use text_edit::TextEditBuilder;
use crate::{
AstNode, Direction, NodeOrToken, SyntaxElement, SyntaxKind, SyntaxNode, SyntaxNodePtr,
SyntaxToken, TextRange, TextSize,
};
/// Returns ancestors of the node at the offset, sorted by length. This should
/// do the right thing at an edge, e.g. when searching for expressions at `{
/// $0foo }` we will get the name reference instead of the whole block, which
/// we would get if we just did `find_token_at_offset(...).flat_map(|t|
/// t.parent().ancestors())`.
pub fn ancestors_at_offset(
node: &SyntaxNode,
offset: TextSize,
) -> impl Iterator<Item = SyntaxNode> {
node.token_at_offset(offset)
.map(|token| token.ancestors())
.kmerge_by(|node1, node2| node1.text_range().len() < node2.text_range().len())
}
/// Finds a node of specific Ast type at offset. Note that this is slightly
/// imprecise: if the cursor is strictly between two nodes of the desired type,
/// as in
///
/// ```no_run
/// struct Foo {}|struct Bar;
/// ```
///
/// then the shorter node will be silently preferred.
pub fn find_node_at_offset<N: AstNode>(syntax: &SyntaxNode, offset: TextSize) -> Option<N> {
ancestors_at_offset(syntax, offset).find_map(N::cast)
}
pub fn find_node_at_range<N: AstNode>(syntax: &SyntaxNode, range: TextRange) -> Option<N> {
syntax.covering_element(range).ancestors().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 {
NodeOrToken::Node(node) => node.siblings_with_tokens(direction).skip(1).find(not_trivia),
NodeOrToken::Token(token) => token.siblings_with_tokens(direction).skip(1).find(not_trivia),
};
fn not_trivia(element: &SyntaxElement) -> bool {
match element {
NodeOrToken::Node(_) => true,
NodeOrToken::Token(token) => !token.kind().is_trivia(),
}
}
}
pub fn least_common_ancestor(u: &SyntaxNode, v: &SyntaxNode) -> Option<SyntaxNode> {
if u == v {
return Some(u.clone());
}
let u_depth = u.ancestors().count();
let v_depth = v.ancestors().count();
let keep = u_depth.min(v_depth);
let u_candidates = u.ancestors().skip(u_depth - keep);
let v_candidates = v.ancestors().skip(v_depth - keep);
let (res, _) = u_candidates.zip(v_candidates).find(|(x, y)| x == y)?;
Some(res)
}
pub fn neighbor<T: AstNode>(me: &T, direction: Direction) -> Option<T> {
me.syntax().siblings(direction).skip(1).find_map(T::cast)
}
pub fn has_errors(node: &SyntaxNode) -> bool {
node.children().any(|it| it.kind() == SyntaxKind::ERROR)
}
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum InsertPosition<T> {
First,
Last,
Before(T),
After(T),
}
type FxIndexMap<K, V> = IndexMap<K, V, BuildHasherDefault<rustc_hash::FxHasher>>;
#[derive(Debug, Hash, PartialEq, Eq)]
enum TreeDiffInsertPos {
After(SyntaxElement),
AsFirstChild(SyntaxElement),
}
#[derive(Debug)]
pub struct TreeDiff {
replacements: FxHashMap<SyntaxElement, SyntaxElement>,
deletions: Vec<SyntaxElement>,
// the vec as well as the indexmap are both here to preserve order
insertions: FxIndexMap<TreeDiffInsertPos, Vec<SyntaxElement>>,
}
impl TreeDiff {
pub fn into_text_edit(&self, builder: &mut TextEditBuilder) {
let _p = profile::span("into_text_edit");
for (anchor, to) in self.insertions.iter() {
let offset = match anchor {
TreeDiffInsertPos::After(it) => it.text_range().end(),
TreeDiffInsertPos::AsFirstChild(it) => it.text_range().start(),
};
to.iter().for_each(|to| builder.insert(offset, to.to_string()));
}
for (from, to) in self.replacements.iter() {
builder.replace(from.text_range(), to.to_string())
}
for text_range in self.deletions.iter().map(SyntaxElement::text_range) {
builder.delete(text_range);
}
}
pub fn is_empty(&self) -> bool {
self.replacements.is_empty() && self.deletions.is_empty() && self.insertions.is_empty()
}
}
/// Finds a (potentially minimal) diff, which, applied to `from`, will result in `to`.
///
/// Specifically, returns a structure that consists of a replacements, insertions and deletions
/// such that applying this map on `from` will result in `to`.
///
/// This function tries to find a fine-grained diff.
pub fn diff(from: &SyntaxNode, to: &SyntaxNode) -> TreeDiff {
let _p = profile::span("diff");
let mut diff = TreeDiff {
replacements: FxHashMap::default(),
insertions: FxIndexMap::default(),
deletions: Vec::new(),
};
let (from, to) = (from.clone().into(), to.clone().into());
if !syntax_element_eq(&from, &to) {
go(&mut diff, from, to);
}
return diff;
fn syntax_element_eq(lhs: &SyntaxElement, rhs: &SyntaxElement) -> bool {
lhs.kind() == rhs.kind()
&& lhs.text_range().len() == rhs.text_range().len()
&& match (&lhs, &rhs) {
(NodeOrToken::Node(lhs), NodeOrToken::Node(rhs)) => {
lhs == rhs || lhs.text() == rhs.text()
}
(NodeOrToken::Token(lhs), NodeOrToken::Token(rhs)) => lhs.text() == rhs.text(),
_ => false,
}
}
// FIXME: this is horrible inefficient. I bet there's a cool algorithm to diff trees properly.
fn go(diff: &mut TreeDiff, lhs: SyntaxElement, rhs: SyntaxElement) {
let (lhs, rhs) = match lhs.as_node().zip(rhs.as_node()) {
Some((lhs, rhs)) => (lhs, rhs),
_ => {
cov_mark::hit!(diff_node_token_replace);
diff.replacements.insert(lhs, rhs);
return;
}
};
let mut look_ahead_scratch = Vec::default();
let mut rhs_children = rhs.children_with_tokens();
let mut lhs_children = lhs.children_with_tokens();
let mut last_lhs = None;
loop {
let lhs_child = lhs_children.next();
match (lhs_child.clone(), rhs_children.next()) {
(None, None) => break,
(None, Some(element)) => {
let insert_pos = match last_lhs.clone() {
Some(prev) => {
cov_mark::hit!(diff_insert);
TreeDiffInsertPos::After(prev)
}
// first iteration, insert into out parent as the first child
None => {
cov_mark::hit!(diff_insert_as_first_child);
TreeDiffInsertPos::AsFirstChild(lhs.clone().into())
}
};
diff.insertions.entry(insert_pos).or_insert_with(Vec::new).push(element);
}
(Some(element), None) => {
cov_mark::hit!(diff_delete);
diff.deletions.push(element);
}
(Some(ref lhs_ele), Some(ref rhs_ele)) if syntax_element_eq(lhs_ele, rhs_ele) => {}
(Some(lhs_ele), Some(rhs_ele)) => {
// nodes differ, look for lhs_ele in rhs, if its found we can mark everything up
// until that element as insertions. This is important to keep the diff minimal
// in regards to insertions that have been actually done, this is important for
// use insertions as we do not want to replace the entire module node.
look_ahead_scratch.push(rhs_ele.clone());
let mut rhs_children_clone = rhs_children.clone();
let mut insert = false;
while let Some(rhs_child) = rhs_children_clone.next() {
if syntax_element_eq(&lhs_ele, &rhs_child) {
cov_mark::hit!(diff_insertions);
insert = true;
break;
} else {
look_ahead_scratch.push(rhs_child);
}
}
let drain = look_ahead_scratch.drain(..);
if insert {
let insert_pos = if let Some(prev) = last_lhs.clone().filter(|_| insert) {
TreeDiffInsertPos::After(prev)
} else {
cov_mark::hit!(insert_first_child);
TreeDiffInsertPos::AsFirstChild(lhs.clone().into())
};
diff.insertions.entry(insert_pos).or_insert_with(Vec::new).extend(drain);
rhs_children = rhs_children_clone;
} else {
go(diff, lhs_ele, rhs_ele)
}
}
}
last_lhs = lhs_child.or(last_lhs);
}
}
}
/// Adds specified children (tokens or nodes) to the current node at the
/// specific position.
///
/// This is a type-unsafe low-level editing API, if you need to use it,
/// prefer to create a type-safe abstraction on top of it instead.
pub fn insert_children(
parent: &SyntaxNode,
position: InsertPosition<SyntaxElement>,
to_insert: impl IntoIterator<Item = SyntaxElement>,
) -> SyntaxNode {
let mut to_insert = to_insert.into_iter();
_insert_children(parent, position, &mut to_insert)
}
fn _insert_children(
parent: &SyntaxNode,
position: InsertPosition<SyntaxElement>,
to_insert: &mut dyn Iterator<Item = SyntaxElement>,
) -> SyntaxNode {
let mut delta = TextSize::default();
let to_insert = to_insert.map(|element| {
delta += element.text_range().len();
to_green_element(element)
});
let parent_green = parent.green();
let mut old_children = parent_green.children().map(|it| match it {
NodeOrToken::Token(it) => NodeOrToken::Token(it.to_owned()),
NodeOrToken::Node(it) => NodeOrToken::Node(it.to_owned()),
});
let new_children = match &position {
InsertPosition::First => to_insert.chain(old_children).collect::<Vec<_>>(),
InsertPosition::Last => old_children.chain(to_insert).collect::<Vec<_>>(),
InsertPosition::Before(anchor) | InsertPosition::After(anchor) => {
let take_anchor = if let InsertPosition::After(_) = position { 1 } else { 0 };
let split_at = position_of_child(parent, anchor.clone()) + take_anchor;
let before = old_children.by_ref().take(split_at).collect::<Vec<_>>();
before.into_iter().chain(to_insert).chain(old_children).collect::<Vec<_>>()
}
};
with_children(parent, new_children)
}
/// Replaces all nodes in `to_delete` with nodes from `to_insert`
///
/// This is a type-unsafe low-level editing API, if you need to use it,
/// prefer to create a type-safe abstraction on top of it instead.
pub fn replace_children(
parent: &SyntaxNode,
to_delete: RangeInclusive<SyntaxElement>,
to_insert: impl IntoIterator<Item = SyntaxElement>,
) -> SyntaxNode {
let mut to_insert = to_insert.into_iter();
_replace_children(parent, to_delete, &mut to_insert)
}
fn _replace_children(
parent: &SyntaxNode,
to_delete: RangeInclusive<SyntaxElement>,
to_insert: &mut dyn Iterator<Item = SyntaxElement>,
) -> SyntaxNode {
let start = position_of_child(parent, to_delete.start().clone());
let end = position_of_child(parent, to_delete.end().clone());
let parent_green = parent.green();
let mut old_children = parent_green.children().map(|it| match it {
NodeOrToken::Token(it) => NodeOrToken::Token(it.to_owned()),
NodeOrToken::Node(it) => NodeOrToken::Node(it.to_owned()),
});
let before = old_children.by_ref().take(start).collect::<Vec<_>>();
let new_children = before
.into_iter()
.chain(to_insert.map(to_green_element))
.chain(old_children.skip(end + 1 - start))
.collect::<Vec<_>>();
with_children(parent, new_children)
}
#[derive(Debug, PartialEq, Eq, Hash)]
enum InsertPos {
FirstChildOf(SyntaxNode),
After(SyntaxElement),
}
#[derive(Default)]
pub struct SyntaxRewriter<'a> {
f: Option<Box<dyn Fn(&SyntaxElement) -> Option<SyntaxElement> + 'a>>,
//FIXME: add debug_assertions that all elements are in fact from the same file.
replacements: FxHashMap<SyntaxElement, Replacement>,
insertions: IndexMap<InsertPos, Vec<SyntaxElement>>,
}
impl fmt::Debug for SyntaxRewriter<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("SyntaxRewriter")
.field("replacements", &self.replacements)
.field("insertions", &self.insertions)
.finish()
}
}
impl<'a> SyntaxRewriter<'a> {
pub fn from_fn(f: impl Fn(&SyntaxElement) -> Option<SyntaxElement> + 'a) -> SyntaxRewriter<'a> {
SyntaxRewriter {
f: Some(Box::new(f)),
replacements: FxHashMap::default(),
insertions: IndexMap::default(),
}
}
pub fn delete<T: Clone + Into<SyntaxElement>>(&mut self, what: &T) {
let what = what.clone().into();
let replacement = Replacement::Delete;
self.replacements.insert(what, replacement);
}
pub fn insert_before<T: Clone + Into<SyntaxElement>, U: Clone + Into<SyntaxElement>>(
&mut self,
before: &T,
what: &U,
) {
let before = before.clone().into();
let pos = match before.prev_sibling_or_token() {
Some(sibling) => InsertPos::After(sibling),
None => match before.parent() {
Some(parent) => InsertPos::FirstChildOf(parent),
None => return,
},
};
self.insertions.entry(pos).or_insert_with(Vec::new).push(what.clone().into());
}
pub fn insert_after<T: Clone + Into<SyntaxElement>, U: Clone + Into<SyntaxElement>>(
&mut self,
after: &T,
what: &U,
) {
self.insertions
.entry(InsertPos::After(after.clone().into()))
.or_insert_with(Vec::new)
.push(what.clone().into());
}
pub fn insert_as_first_child<T: Clone + Into<SyntaxNode>, U: Clone + Into<SyntaxElement>>(
&mut self,
parent: &T,
what: &U,
) {
self.insertions
.entry(InsertPos::FirstChildOf(parent.clone().into()))
.or_insert_with(Vec::new)
.push(what.clone().into());
}
pub fn insert_many_before<
T: Clone + Into<SyntaxElement>,
U: IntoIterator<Item = SyntaxElement>,
>(
&mut self,
before: &T,
what: U,
) {
let before = before.clone().into();
let pos = match before.prev_sibling_or_token() {
Some(sibling) => InsertPos::After(sibling),
None => match before.parent() {
Some(parent) => InsertPos::FirstChildOf(parent),
None => return,
},
};
self.insertions.entry(pos).or_insert_with(Vec::new).extend(what);
}
pub fn insert_many_after<
T: Clone + Into<SyntaxElement>,
U: IntoIterator<Item = SyntaxElement>,
>(
&mut self,
after: &T,
what: U,
) {
self.insertions
.entry(InsertPos::After(after.clone().into()))
.or_insert_with(Vec::new)
.extend(what);
}
pub fn insert_many_as_first_children<
T: Clone + Into<SyntaxNode>,
U: IntoIterator<Item = SyntaxElement>,
>(
&mut self,
parent: &T,
what: U,
) {
self.insertions
.entry(InsertPos::FirstChildOf(parent.clone().into()))
.or_insert_with(Vec::new)
.extend(what)
}
pub fn replace<T: Clone + Into<SyntaxElement>>(&mut self, what: &T, with: &T) {
let what = what.clone().into();
let replacement = Replacement::Single(with.clone().into());
self.replacements.insert(what, replacement);
}
pub fn replace_with_many<T: Clone + Into<SyntaxElement>>(
&mut self,
what: &T,
with: Vec<SyntaxElement>,
) {
let what = what.clone().into();
let replacement = Replacement::Many(with);
self.replacements.insert(what, replacement);
}
pub fn replace_ast<T: AstNode>(&mut self, what: &T, with: &T) {
self.replace(what.syntax(), with.syntax())
}
pub fn rewrite(&self, node: &SyntaxNode) -> SyntaxNode {
let _p = profile::span("rewrite");
if self.f.is_none() && self.replacements.is_empty() && self.insertions.is_empty() {
return node.clone();
}
let green = self.rewrite_children(node);
with_green(node, green)
}
pub fn rewrite_ast<N: AstNode>(self, node: &N) -> N {
N::cast(self.rewrite(node.syntax())).unwrap()
}
/// Returns a node that encompasses all replacements to be done by this rewriter.
///
/// Passing the returned node to `rewrite` will apply all replacements queued up in `self`.
///
/// Returns `None` when there are no replacements.
pub fn rewrite_root(&self) -> Option<SyntaxNode> {
let _p = profile::span("rewrite_root");
fn element_to_node_or_parent(element: &SyntaxElement) -> Option<SyntaxNode> {
match element {
SyntaxElement::Node(it) => Some(it.clone()),
SyntaxElement::Token(it) => it.parent(),
}
}
assert!(self.f.is_none());
self.replacements
.keys()
.filter_map(element_to_node_or_parent)
.chain(self.insertions.keys().filter_map(|pos| match pos {
InsertPos::FirstChildOf(it) => Some(it.clone()),
InsertPos::After(it) => element_to_node_or_parent(it),
}))
// If we only have one replacement/insertion, we must return its parent node, since `rewrite` does
// not replace the node passed to it.
.map(|it| it.parent().unwrap_or(it))
.fold1(|a, b| least_common_ancestor(&a, &b).unwrap())
}
fn replacement(&self, element: &SyntaxElement) -> Option<Replacement> {
if let Some(f) = &self.f {
assert!(self.replacements.is_empty());
return f(element).map(Replacement::Single);
}
self.replacements.get(element).cloned()
}
fn insertions(&self, pos: &InsertPos) -> Option<impl Iterator<Item = SyntaxElement> + '_> {
self.insertions.get(pos).map(|insertions| insertions.iter().cloned())
}
fn rewrite_children(&self, node: &SyntaxNode) -> rowan::GreenNode {
let _p = profile::span("rewrite_children");
// FIXME: this could be made much faster.
let mut new_children = Vec::new();
if let Some(elements) = self.insertions(&InsertPos::FirstChildOf(node.clone())) {
new_children.extend(elements.map(element_to_green));
}
for child in node.children_with_tokens() {
self.rewrite_self(&mut new_children, &child);
}
rowan::GreenNode::new(rowan::SyntaxKind(node.kind() as u16), new_children)
}
fn rewrite_self(
&self,
acc: &mut Vec<NodeOrToken<rowan::GreenNode, rowan::GreenToken>>,
element: &SyntaxElement,
) {
let _p = profile::span("rewrite_self");
if let Some(replacement) = self.replacement(&element) {
match replacement {
Replacement::Single(element) => acc.push(element_to_green(element)),
Replacement::Many(replacements) => {
acc.extend(replacements.into_iter().map(element_to_green))
}
Replacement::Delete => (),
};
} else {
match element {
NodeOrToken::Token(it) => acc.push(NodeOrToken::Token(it.green().to_owned())),
NodeOrToken::Node(it) => {
acc.push(NodeOrToken::Node(self.rewrite_children(it)));
}
}
}
if let Some(elements) = self.insertions(&InsertPos::After(element.clone())) {
acc.extend(elements.map(element_to_green));
}
}
}
fn element_to_green(element: SyntaxElement) -> NodeOrToken<rowan::GreenNode, rowan::GreenToken> {
match element {
NodeOrToken::Node(it) => NodeOrToken::Node(it.green().to_owned()),
NodeOrToken::Token(it) => NodeOrToken::Token(it.green().to_owned()),
}
}
impl ops::AddAssign for SyntaxRewriter<'_> {
fn add_assign(&mut self, rhs: SyntaxRewriter) {
assert!(rhs.f.is_none());
self.replacements.extend(rhs.replacements);
for (pos, insertions) in rhs.insertions.into_iter() {
match self.insertions.entry(pos) {
indexmap::map::Entry::Occupied(mut occupied) => {
occupied.get_mut().extend(insertions)
}
indexmap::map::Entry::Vacant(vacant) => drop(vacant.insert(insertions)),
}
}
}
}
#[derive(Clone, Debug)]
enum Replacement {
Delete,
Single(SyntaxElement),
Many(Vec<SyntaxElement>),
}
fn with_children(
parent: &SyntaxNode,
new_children: Vec<NodeOrToken<rowan::GreenNode, rowan::GreenToken>>,
) -> SyntaxNode {
let _p = profile::span("with_children");
let new_green = rowan::GreenNode::new(rowan::SyntaxKind(parent.kind() as u16), new_children);
with_green(parent, new_green)
}
fn with_green(syntax_node: &SyntaxNode, green: rowan::GreenNode) -> SyntaxNode {
let len = green.children().map(|it| it.text_len()).sum::<TextSize>();
let new_root_node = syntax_node.replace_with(green);
let new_root_node = SyntaxNode::new_root(new_root_node);
// FIXME: use a more elegant way to re-fetch the node (#1185), make
// `range` private afterwards
let mut ptr = SyntaxNodePtr::new(syntax_node);
ptr.range = TextRange::at(ptr.range.start(), len);
ptr.to_node(&new_root_node)
}
fn position_of_child(parent: &SyntaxNode, child: SyntaxElement) -> usize {
parent
.children_with_tokens()
.position(|it| it == child)
.expect("element is not a child of current element")
}
fn to_green_element(element: SyntaxElement) -> NodeOrToken<rowan::GreenNode, rowan::GreenToken> {
match element {
NodeOrToken::Node(it) => it.green().to_owned().into(),
NodeOrToken::Token(it) => it.green().to_owned().into(),
}
}
#[cfg(test)]
mod tests {
use expect_test::{expect, Expect};
use itertools::Itertools;
use parser::SyntaxKind;
use text_edit::TextEdit;
use crate::{AstNode, SyntaxElement};
#[test]
fn replace_node_token() {
cov_mark::check!(diff_node_token_replace);
check_diff(
r#"use node;"#,
r#"ident"#,
expect![[r#"
insertions:
replacements:
Line 0: Token(USE_KW@0..3 "use") -> ident
deletions:
Line 1: " "
Line 1: node
Line 1: ;
"#]],
);
}
#[test]
fn replace_parent() {
cov_mark::check!(diff_insert_as_first_child);
check_diff(
r#""#,
r#"use foo::bar;"#,
expect![[r#"
insertions:
Line 0: AsFirstChild(Node(SOURCE_FILE@0..0))
-> use foo::bar;
replacements:
deletions:
"#]],
);
}
#[test]
fn insert_last() {
cov_mark::check!(diff_insert);
check_diff(
r#"
use foo;
use bar;"#,
r#"
use foo;
use bar;
use baz;"#,
expect![[r#"
insertions:
Line 2: After(Node(USE@10..18))
-> "\n"
-> use baz;
replacements:
deletions:
"#]],
);
}
#[test]
fn insert_middle() {
check_diff(
r#"
use foo;
use baz;"#,
r#"
use foo;
use bar;
use baz;"#,
expect![[r#"
insertions:
Line 2: After(Token(WHITESPACE@9..10 "\n"))
-> use bar;
-> "\n"
replacements:
deletions:
"#]],
)
}
#[test]
fn insert_first() {
check_diff(
r#"
use bar;
use baz;"#,
r#"
use foo;
use bar;
use baz;"#,
expect![[r#"
insertions:
Line 0: After(Token(WHITESPACE@0..1 "\n"))
-> use foo;
-> "\n"
replacements:
deletions:
"#]],
)
}
#[test]
fn first_child_insertion() {
cov_mark::check!(insert_first_child);
check_diff(
r#"fn main() {
stdi
}"#,
r#"use foo::bar;
fn main() {
stdi
}"#,
expect![[r#"
insertions:
Line 0: AsFirstChild(Node(SOURCE_FILE@0..30))
-> use foo::bar;
-> "\n\n "
replacements:
deletions:
"#]],
);
}
#[test]
fn delete_last() {
cov_mark::check!(diff_delete);
check_diff(
r#"use foo;
use bar;"#,
r#"use foo;"#,
expect![[r#"
insertions:
replacements:
deletions:
Line 1: "\n "
Line 2: use bar;
"#]],
);
}
#[test]
fn delete_middle() {
cov_mark::check!(diff_insertions);
check_diff(
r#"
use expect_test::{expect, Expect};
use text_edit::TextEdit;
use crate::AstNode;
"#,
r#"
use expect_test::{expect, Expect};
use crate::AstNode;
"#,
expect![[r#"
insertions:
Line 1: After(Node(USE@1..35))
-> "\n\n"
-> use crate::AstNode;
replacements:
deletions:
Line 2: use text_edit::TextEdit;
Line 3: "\n\n"
Line 4: use crate::AstNode;
Line 5: "\n"
"#]],
)
}
#[test]
fn delete_first() {
check_diff(
r#"
use text_edit::TextEdit;
use crate::AstNode;
"#,
r#"
use crate::AstNode;
"#,
expect![[r#"
insertions:
replacements:
Line 2: Token(IDENT@5..14 "text_edit") -> crate
Line 2: Token(IDENT@16..24 "TextEdit") -> AstNode
Line 2: Token(WHITESPACE@25..27 "\n\n") -> "\n"
deletions:
Line 3: use crate::AstNode;
Line 4: "\n"
"#]],
)
}
#[test]
fn merge_use() {
check_diff(
r#"
use std::{
fmt,
hash::BuildHasherDefault,
ops::{self, RangeInclusive},
};
"#,
r#"
use std::fmt;
use std::hash::BuildHasherDefault;
use std::ops::{self, RangeInclusive};
"#,
expect![[r#"
insertions:
Line 2: After(Node(PATH_SEGMENT@5..8))
-> ::
-> fmt
Line 6: After(Token(WHITESPACE@86..87 "\n"))
-> use std::hash::BuildHasherDefault;
-> "\n"
-> use std::ops::{self, RangeInclusive};
-> "\n"
replacements:
Line 2: Token(IDENT@5..8 "std") -> std
deletions:
Line 2: ::
Line 2: {
fmt,
hash::BuildHasherDefault,
ops::{self, RangeInclusive},
}
"#]],
)
}
#[test]
fn early_return_assist() {
check_diff(
r#"
fn main() {
if let Ok(x) = Err(92) {
foo(x);
}
}
"#,
r#"
fn main() {
let x = match Err(92) {
Ok(it) => it,
_ => return,
};
foo(x);
}
"#,
expect![[r#"
insertions:
Line 3: After(Node(BLOCK_EXPR@40..63))
-> " "
-> match Err(92) {
Ok(it) => it,
_ => return,
}
-> ;
Line 3: After(Node(IF_EXPR@17..63))
-> "\n "
-> foo(x);
replacements:
Line 3: Token(IF_KW@17..19 "if") -> let
Line 3: Token(LET_KW@20..23 "let") -> x
Line 3: Node(BLOCK_EXPR@40..63) -> =
deletions:
Line 3: " "
Line 3: Ok(x)
Line 3: " "
Line 3: =
Line 3: " "
Line 3: Err(92)
"#]],
)
}
fn check_diff(from: &str, to: &str, expected_diff: Expect) {
let from_node = crate::SourceFile::parse(from).tree().syntax().clone();
let to_node = crate::SourceFile::parse(to).tree().syntax().clone();
let diff = super::diff(&from_node, &to_node);
let line_number =
|syn: &SyntaxElement| from[..syn.text_range().start().into()].lines().count();
let fmt_syntax = |syn: &SyntaxElement| match syn.kind() {
SyntaxKind::WHITESPACE => format!("{:?}", syn.to_string()),
_ => format!("{}", syn),
};
let insertions =
diff.insertions.iter().format_with("\n", |(k, v), f| -> Result<(), std::fmt::Error> {
f(&format!(
"Line {}: {:?}\n-> {}",
line_number(match k {
super::TreeDiffInsertPos::After(syn) => syn,
super::TreeDiffInsertPos::AsFirstChild(syn) => syn,
}),
k,
v.iter().format_with("\n-> ", |v, f| f(&fmt_syntax(v)))
))
});
let replacements = diff
.replacements
.iter()
.sorted_by_key(|(syntax, _)| syntax.text_range().start())
.format_with("\n", |(k, v), f| {
f(&format!("Line {}: {:?} -> {}", line_number(k), k, fmt_syntax(v)))
});
let deletions = diff
.deletions
.iter()
.format_with("\n", |v, f| f(&format!("Line {}: {}", line_number(v), &fmt_syntax(v))));
let actual = format!(
"insertions:\n\n{}\n\nreplacements:\n\n{}\n\ndeletions:\n\n{}\n",
insertions, replacements, deletions
);
expected_diff.assert_eq(&actual);
let mut from = from.to_owned();
let mut text_edit = TextEdit::builder();
diff.into_text_edit(&mut text_edit);
text_edit.finish().apply(&mut from);
assert_eq!(&*from, to, "diff did not turn `from` to `to`");
}
}
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