10543: Narrow add_missing_match_arms assist range r=Veykril a=antonfirsov

Contributes to #10220 with logic borrowed from #10267.

Note: if anyone has recommendations for further analyzers to check, I'm happy to (hard to do it on my own, I'm completely new to the language).

Co-authored-by: Anton Firszov <antonfir@gmail.com>
This commit is contained in:
bors[bot] 2021-10-15 16:05:15 +00:00 committed by GitHub
commit c67db1b952
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@ -5,7 +5,8 @@ use hir::{Adt, HasSource, ModuleDef, Semantics};
use ide_db::helpers::{mod_path_to_ast, FamousDefs};
use ide_db::RootDatabase;
use itertools::Itertools;
use syntax::ast::{self, make, AstNode, HasName, MatchArm, Pat};
use syntax::ast::{self, make, AstNode, HasName, MatchArm, MatchArmList, MatchExpr, Pat};
use syntax::TextRange;
use crate::{
utils::{self, render_snippet, Cursor},
@ -39,6 +40,22 @@ use crate::{
pub(crate) fn add_missing_match_arms(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
let match_expr = ctx.find_node_at_offset_with_descend::<ast::MatchExpr>()?;
let match_arm_list = match_expr.match_arm_list()?;
let target_range: TextRange;
if let None = cursor_at_trivial_match_arm_list(&ctx, &match_expr, &match_arm_list) {
target_range = TextRange::new(
ctx.sema.original_range(match_expr.syntax()).range.start(),
ctx.sema.original_range(match_arm_list.syntax()).range.start(),
);
let cursor_in_range = target_range.contains_range(ctx.selection_trimmed());
if !cursor_in_range {
cov_mark::hit!(not_applicable_outside_of_range_right);
return None;
}
} else {
target_range = ctx.sema.original_range(match_expr.syntax()).range;
}
let expr = match_expr.expr()?;
@ -121,11 +138,10 @@ pub(crate) fn add_missing_match_arms(acc: &mut Assists, ctx: &AssistContext) ->
return None;
}
let target = ctx.sema.original_range(match_expr.syntax()).range;
acc.add(
AssistId("add_missing_match_arms", AssistKind::QuickFix),
"Fill match arms",
target,
target_range,
|builder| {
let new_match_arm_list = match_arm_list.clone_for_update();
let missing_arms = missing_pats
@ -177,6 +193,29 @@ pub(crate) fn add_missing_match_arms(acc: &mut Assists, ctx: &AssistContext) ->
)
}
fn cursor_at_trivial_match_arm_list(
ctx: &AssistContext,
match_expr: &MatchExpr,
match_arm_list: &MatchArmList,
) -> Option<()> {
// match x { $0 }
if match_arm_list.arms().next() == None {
cov_mark::hit!(add_missing_match_arms_empty_body);
return Some(());
}
// match { _$0 => {...} }
let wild_pat = ctx.find_node_at_offset_with_descend::<ast::WildcardPat>()?;
let arm = wild_pat.syntax().parent().and_then(ast::MatchArm::cast)?;
let arm_match_expr = arm.syntax().ancestors().nth(2).and_then(ast::MatchExpr::cast)?;
if arm_match_expr == *match_expr {
cov_mark::hit!(add_missing_match_arms_trivial_arm);
return Some(());
}
None
}
fn is_variant_missing(existing_pats: &[Pat], var: &Pat) -> bool {
!existing_pats.iter().any(|pat| does_pat_match_variant(pat, var))
}
@ -306,6 +345,39 @@ fn main() {
);
}
#[test]
fn not_applicable_outside_of_range_left() {
check_assist_not_applicable(
add_missing_match_arms,
r#"
enum A { X, Y }
fn foo(a: A) {
$0 match a {
A::X => { }
}
}
"#,
);
}
#[test]
fn not_applicable_outside_of_range_right() {
cov_mark::check!(not_applicable_outside_of_range_right);
check_assist_not_applicable(
add_missing_match_arms,
r#"
enum A { X, Y }
fn foo(a: A) {
match a {$0
A::X => { }
}
}
"#,
);
}
#[test]
fn all_boolean_match_arms_provided() {
check_assist_not_applicable(
@ -583,6 +655,7 @@ fn main() {
#[test]
fn add_missing_match_arms_empty_body() {
cov_mark::check!(add_missing_match_arms_empty_body);
check_assist(
add_missing_match_arms,
r#"
@ -590,7 +663,7 @@ enum A { As, Bs, Cs(String), Ds(String, String), Es { x: usize, y: usize } }
fn main() {
let a = A::As;
match a$0 {}
match a {$0}
}
"#,
r#"
@ -853,7 +926,7 @@ fn foo(a: &mut A) {
}
#[test]
fn add_missing_match_arms_target() {
fn add_missing_match_arms_target_simple() {
check_assist_target(
add_missing_match_arms,
r#"
@ -867,8 +940,26 @@ fn main() {
);
}
#[test]
fn add_missing_match_arms_target_complex() {
check_assist_target(
add_missing_match_arms,
r#"
enum E { X, Y }
fn main() {
match E::X$0 {
E::X => {}
}
}
"#,
"match E::X ",
);
}
#[test]
fn add_missing_match_arms_trivial_arm() {
cov_mark::check!(add_missing_match_arms_trivial_arm);
check_assist(
add_missing_match_arms,
r#"
@ -893,6 +984,25 @@ fn main() {
);
}
#[test]
fn wildcard_inside_expression_not_applicable() {
check_assist_not_applicable(
add_missing_match_arms,
r#"
enum E { X, Y }
fn foo(e : E) {
match e {
_ => {
println!("1");$0
println!("2");
}
}
}
"#,
);
}
#[test]
fn add_missing_match_arms_qualifies_path() {
check_assist(
@ -928,8 +1038,8 @@ fn main() {
r#"
enum A { One, Two }
fn foo(a: A) {
match a {
// foo bar baz$0
match a $0 {
// foo bar baz
A::One => {}
// This is where the rest should be
}
@ -938,7 +1048,7 @@ fn foo(a: A) {
r#"
enum A { One, Two }
fn foo(a: A) {
match a {
match a {
// foo bar baz
A::One => {}
$0A::Two => todo!(),