Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide_assists/src/handlers/add_missing_match_arms.rs')
-rw-r--r--crates/ide_assists/src/handlers/add_missing_match_arms.rs1133
1 files changed, 1133 insertions, 0 deletions
diff --git a/crates/ide_assists/src/handlers/add_missing_match_arms.rs b/crates/ide_assists/src/handlers/add_missing_match_arms.rs
new file mode 100644
index 0000000000..cdbd8ac183
--- /dev/null
+++ b/crates/ide_assists/src/handlers/add_missing_match_arms.rs
@@ -0,0 +1,1133 @@
+use std::iter::{self, Peekable};
+
+use either::Either;
+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, MatchArm, NameOwner, Pat};
+
+use crate::{
+ utils::{self, render_snippet, Cursor},
+ AssistContext, AssistId, AssistKind, Assists,
+};
+
+// Assist: add_missing_match_arms
+//
+// Adds missing clauses to a `match` expression.
+//
+// ```
+// enum Action { Move { distance: u32 }, Stop }
+//
+// fn handle(action: Action) {
+// match action {
+// $0
+// }
+// }
+// ```
+// ->
+// ```
+// enum Action { Move { distance: u32 }, Stop }
+//
+// fn handle(action: Action) {
+// match action {
+// $0Action::Move { distance } => todo!(),
+// Action::Stop => todo!(),
+// }
+// }
+// ```
+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 expr = match_expr.expr()?;
+
+ let mut arms: Vec<MatchArm> = match_arm_list.arms().collect();
+ if let [arm] = arms.as_slice() {
+ if let Some(Pat::WildcardPat(..)) = arm.pat() {
+ arms.clear();
+ }
+ }
+
+ let top_lvl_pats: Vec<_> = arms
+ .iter()
+ .filter_map(ast::MatchArm::pat)
+ .flat_map(|pat| match pat {
+ // Special case OrPat as separate top-level pats
+ Pat::OrPat(or_pat) => Either::Left(or_pat.pats()),
+ _ => Either::Right(iter::once(pat)),
+ })
+ // Exclude top level wildcards so that they are expanded by this assist, retains status quo in #8129.
+ .filter(|pat| !matches!(pat, Pat::WildcardPat(_)))
+ .collect();
+
+ let module = ctx.sema.scope(expr.syntax()).module()?;
+
+ let mut missing_pats: Peekable<Box<dyn Iterator<Item = ast::Pat>>> = if let Some(enum_def) =
+ resolve_enum_def(&ctx.sema, &expr)
+ {
+ let variants = enum_def.variants(ctx.db());
+
+ let missing_pats = variants
+ .into_iter()
+ .filter_map(|variant| build_pat(ctx.db(), module, variant))
+ .filter(|variant_pat| is_variant_missing(&top_lvl_pats, variant_pat));
+
+ let option_enum =
+ FamousDefs(&ctx.sema, Some(module.krate())).core_option_Option().map(lift_enum);
+ let missing_pats: Box<dyn Iterator<Item = _>> = if Some(enum_def) == option_enum {
+ // Match `Some` variant first.
+ cov_mark::hit!(option_order);
+ Box::new(missing_pats.rev())
+ } else {
+ Box::new(missing_pats)
+ };
+ missing_pats.peekable()
+ } else if let Some(enum_defs) = resolve_tuple_of_enum_def(&ctx.sema, &expr) {
+ let mut n_arms = 1;
+ let variants_of_enums: Vec<Vec<ExtendedVariant>> = enum_defs
+ .into_iter()
+ .map(|enum_def| enum_def.variants(ctx.db()))
+ .inspect(|variants| n_arms *= variants.len())
+ .collect();
+
+ // When calculating the match arms for a tuple of enums, we want
+ // to create a match arm for each possible combination of enum
+ // values. The `multi_cartesian_product` method transforms
+ // Vec<Vec<EnumVariant>> into Vec<(EnumVariant, .., EnumVariant)>
+ // where each tuple represents a proposed match arm.
+
+ // A number of arms grows very fast on even a small tuple of large enums.
+ // We skip the assist beyond an arbitrary threshold.
+ if n_arms > 256 {
+ return None;
+ }
+ let missing_pats = variants_of_enums
+ .into_iter()
+ .multi_cartesian_product()
+ .inspect(|_| cov_mark::hit!(add_missing_match_arms_lazy_computation))
+ .map(|variants| {
+ let patterns =
+ variants.into_iter().filter_map(|variant| build_pat(ctx.db(), module, variant));
+ ast::Pat::from(make::tuple_pat(patterns))
+ })
+ .filter(|variant_pat| is_variant_missing(&top_lvl_pats, variant_pat));
+ (Box::new(missing_pats) as Box<dyn Iterator<Item = _>>).peekable()
+ } else {
+ return None;
+ };
+
+ if missing_pats.peek().is_none() {
+ 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,
+ |builder| {
+ let new_match_arm_list = match_arm_list.clone_for_update();
+ let missing_arms = missing_pats
+ .map(|pat| make::match_arm(iter::once(pat), None, make::ext::expr_todo()))
+ .map(|it| it.clone_for_update());
+
+ let catch_all_arm = new_match_arm_list
+ .arms()
+ .find(|arm| matches!(arm.pat(), Some(ast::Pat::WildcardPat(_))));
+ if let Some(arm) = catch_all_arm {
+ let is_empty_expr = arm.expr().map_or(true, |e| match e {
+ ast::Expr::BlockExpr(b) => {
+ b.statements().next().is_none() && b.tail_expr().is_none()
+ }
+ ast::Expr::TupleExpr(t) => t.fields().next().is_none(),
+ _ => false,
+ });
+ if is_empty_expr {
+ arm.remove();
+ } else {
+ cov_mark::hit!(add_missing_match_arms_empty_expr);
+ }
+ }
+ let mut first_new_arm = None;
+ for arm in missing_arms {
+ first_new_arm.get_or_insert_with(|| arm.clone());
+ new_match_arm_list.add_arm(arm);
+ }
+
+ let old_range = ctx.sema.original_range(match_arm_list.syntax()).range;
+ match (first_new_arm, ctx.config.snippet_cap) {
+ (Some(first_new_arm), Some(cap)) => {
+ let extend_lifetime;
+ let cursor =
+ match first_new_arm.syntax().descendants().find_map(ast::WildcardPat::cast)
+ {
+ Some(it) => {
+ extend_lifetime = it.syntax().clone();
+ Cursor::Replace(&extend_lifetime)
+ }
+ None => Cursor::Before(first_new_arm.syntax()),
+ };
+ let snippet = render_snippet(cap, new_match_arm_list.syntax(), cursor);
+ builder.replace_snippet(cap, old_range, snippet);
+ }
+ _ => builder.replace(old_range, new_match_arm_list.to_string()),
+ }
+ },
+ )
+}
+
+fn is_variant_missing(existing_pats: &[Pat], var: &Pat) -> bool {
+ !existing_pats.iter().any(|pat| does_pat_match_variant(pat, var))
+}
+
+// Fixme: this is still somewhat limited, use hir_ty::diagnostics::match_check?
+fn does_pat_match_variant(pat: &Pat, var: &Pat) -> bool {
+ match (pat, var) {
+ (Pat::WildcardPat(_), _) => true,
+ (Pat::TuplePat(tpat), Pat::TuplePat(tvar)) => {
+ tpat.fields().zip(tvar.fields()).all(|(p, v)| does_pat_match_variant(&p, &v))
+ }
+ _ => utils::does_pat_match_variant(pat, var),
+ }
+}
+
+#[derive(Eq, PartialEq, Clone, Copy)]
+enum ExtendedEnum {
+ Bool,
+ Enum(hir::Enum),
+}
+
+#[derive(Eq, PartialEq, Clone, Copy)]
+enum ExtendedVariant {
+ True,
+ False,
+ Variant(hir::Variant),
+}
+
+fn lift_enum(e: hir::Enum) -> ExtendedEnum {
+ ExtendedEnum::Enum(e)
+}
+
+impl ExtendedEnum {
+ fn variants(self, db: &RootDatabase) -> Vec<ExtendedVariant> {
+ match self {
+ ExtendedEnum::Enum(e) => {
+ e.variants(db).into_iter().map(ExtendedVariant::Variant).collect::<Vec<_>>()
+ }
+ ExtendedEnum::Bool => {
+ Vec::<ExtendedVariant>::from([ExtendedVariant::True, ExtendedVariant::False])
+ }
+ }
+ }
+}
+
+fn resolve_enum_def(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Option<ExtendedEnum> {
+ sema.type_of_expr(expr)?.adjusted().autoderef(sema.db).find_map(|ty| match ty.as_adt() {
+ Some(Adt::Enum(e)) => Some(ExtendedEnum::Enum(e)),
+ _ => ty.is_bool().then(|| ExtendedEnum::Bool),
+ })
+}
+
+fn resolve_tuple_of_enum_def(
+ sema: &Semantics<RootDatabase>,
+ expr: &ast::Expr,
+) -> Option<Vec<ExtendedEnum>> {
+ sema.type_of_expr(expr)?
+ .adjusted()
+ .tuple_fields(sema.db)
+ .iter()
+ .map(|ty| {
+ ty.autoderef(sema.db).find_map(|ty| match ty.as_adt() {
+ Some(Adt::Enum(e)) => Some(lift_enum(e)),
+ // For now we only handle expansion for a tuple of enums. Here
+ // we map non-enum items to None and rely on `collect` to
+ // convert Vec<Option<hir::Enum>> into Option<Vec<hir::Enum>>.
+ _ => ty.is_bool().then(|| ExtendedEnum::Bool),
+ })
+ })
+ .collect()
+}
+
+fn build_pat(db: &RootDatabase, module: hir::Module, var: ExtendedVariant) -> Option<ast::Pat> {
+ match var {
+ ExtendedVariant::Variant(var) => {
+ let path = mod_path_to_ast(&module.find_use_path(db, ModuleDef::from(var))?);
+
+ // FIXME: use HIR for this; it doesn't currently expose struct vs. tuple vs. unit variants though
+ let pat: ast::Pat = match var.source(db)?.value.kind() {
+ ast::StructKind::Tuple(field_list) => {
+ let pats =
+ iter::repeat(make::wildcard_pat().into()).take(field_list.fields().count());
+ make::tuple_struct_pat(path, pats).into()
+ }
+ ast::StructKind::Record(field_list) => {
+ let pats = field_list
+ .fields()
+ .map(|f| make::ext::simple_ident_pat(f.name().unwrap()).into());
+ make::record_pat(path, pats).into()
+ }
+ ast::StructKind::Unit => make::path_pat(path),
+ };
+
+ Some(pat)
+ }
+ ExtendedVariant::True => Some(ast::Pat::from(make::literal_pat("true"))),
+ ExtendedVariant::False => Some(ast::Pat::from(make::literal_pat("false"))),
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use crate::tests::{
+ check_assist, check_assist_not_applicable, check_assist_target, check_assist_unresolved,
+ };
+
+ use super::add_missing_match_arms;
+
+ #[test]
+ fn all_match_arms_provided() {
+ check_assist_not_applicable(
+ add_missing_match_arms,
+ r#"
+enum A {
+ As,
+ Bs{x:i32, y:Option<i32>},
+ Cs(i32, Option<i32>),
+}
+fn main() {
+ match A::As$0 {
+ A::As,
+ A::Bs{x,y:Some(_)} => {}
+ A::Cs(_, Some(_)) => {}
+ }
+}
+ "#,
+ );
+ }
+
+ #[test]
+ fn all_boolean_match_arms_provided() {
+ check_assist_not_applicable(
+ add_missing_match_arms,
+ r#"
+fn foo(a: bool) {
+ match a$0 {
+ true => {}
+ false => {}
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn tuple_of_non_enum() {
+ // for now this case is not handled, although it potentially could be
+ // in the future
+ check_assist_not_applicable(
+ add_missing_match_arms,
+ r#"
+fn main() {
+ match (0, false)$0 {
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_boolean() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+fn foo(a: bool) {
+ match a$0 {
+ }
+}
+"#,
+ r#"
+fn foo(a: bool) {
+ match a {
+ $0true => todo!(),
+ false => todo!(),
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn partial_fill_boolean() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+fn foo(a: bool) {
+ match a$0 {
+ true => {}
+ }
+}
+"#,
+ r#"
+fn foo(a: bool) {
+ match a {
+ true => {}
+ $0false => todo!(),
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn all_boolean_tuple_arms_provided() {
+ check_assist_not_applicable(
+ add_missing_match_arms,
+ r#"
+fn foo(a: bool) {
+ match (a, a)$0 {
+ (true, true) => {}
+ (true, false) => {}
+ (false, true) => {}
+ (false, false) => {}
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn fill_boolean_tuple() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+fn foo(a: bool) {
+ match (a, a)$0 {
+ }
+}
+"#,
+ r#"
+fn foo(a: bool) {
+ match (a, a) {
+ $0(true, true) => todo!(),
+ (true, false) => todo!(),
+ (false, true) => todo!(),
+ (false, false) => todo!(),
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn partial_fill_boolean_tuple() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+fn foo(a: bool) {
+ match (a, a)$0 {
+ (false, true) => {}
+ }
+}
+"#,
+ r#"
+fn foo(a: bool) {
+ match (a, a) {
+ (false, true) => {}
+ $0(true, true) => todo!(),
+ (true, false) => todo!(),
+ (false, false) => todo!(),
+ }
+}
+"#,
+ )
+ }
+
+ #[test]
+ fn partial_fill_record_tuple() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A {
+ As,
+ Bs { x: i32, y: Option<i32> },
+ Cs(i32, Option<i32>),
+}
+fn main() {
+ match A::As$0 {
+ A::Bs { x, y: Some(_) } => {}
+ A::Cs(_, Some(_)) => {}
+ }
+}
+"#,
+ r#"
+enum A {
+ As,
+ Bs { x: i32, y: Option<i32> },
+ Cs(i32, Option<i32>),
+}
+fn main() {
+ match A::As {
+ A::Bs { x, y: Some(_) } => {}
+ A::Cs(_, Some(_)) => {}
+ $0A::As => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn partial_fill_option() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+//- minicore: option
+fn main() {
+ match None$0 {
+ None => {}
+ }
+}
+"#,
+ r#"
+fn main() {
+ match None {
+ None => {}
+ Some(${0:_}) => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn partial_fill_or_pat() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { As, Bs, Cs(Option<i32>) }
+fn main() {
+ match A::As$0 {
+ A::Cs(_) | A::Bs => {}
+ }
+}
+"#,
+ r#"
+enum A { As, Bs, Cs(Option<i32>) }
+fn main() {
+ match A::As {
+ A::Cs(_) | A::Bs => {}
+ $0A::As => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn partial_fill() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { As, Bs, Cs, Ds(String), Es(B) }
+enum B { Xs, Ys }
+fn main() {
+ match A::As$0 {
+ A::Bs if 0 < 1 => {}
+ A::Ds(_value) => { let x = 1; }
+ A::Es(B::Xs) => (),
+ }
+}
+"#,
+ r#"
+enum A { As, Bs, Cs, Ds(String), Es(B) }
+enum B { Xs, Ys }
+fn main() {
+ match A::As {
+ A::Bs if 0 < 1 => {}
+ A::Ds(_value) => { let x = 1; }
+ A::Es(B::Xs) => (),
+ $0A::As => todo!(),
+ A::Cs => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn partial_fill_bind_pat() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { As, Bs, Cs(Option<i32>) }
+fn main() {
+ match A::As$0 {
+ A::As(_) => {}
+ a @ A::Bs(_) => {}
+ }
+}
+"#,
+ r#"
+enum A { As, Bs, Cs(Option<i32>) }
+fn main() {
+ match A::As {
+ A::As(_) => {}
+ a @ A::Bs(_) => {}
+ A::Cs(${0:_}) => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_empty_body() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { As, Bs, Cs(String), Ds(String, String), Es { x: usize, y: usize } }
+
+fn main() {
+ let a = A::As;
+ match a$0 {}
+}
+"#,
+ r#"
+enum A { As, Bs, Cs(String), Ds(String, String), Es { x: usize, y: usize } }
+
+fn main() {
+ let a = A::As;
+ match a {
+ $0A::As => todo!(),
+ A::Bs => todo!(),
+ A::Cs(_) => todo!(),
+ A::Ds(_, _) => todo!(),
+ A::Es { x, y } => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_tuple_of_enum() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { One, Two }
+enum B { One, Two }
+
+fn main() {
+ let a = A::One;
+ let b = B::One;
+ match (a$0, b) {}
+}
+"#,
+ r#"
+enum A { One, Two }
+enum B { One, Two }
+
+fn main() {
+ let a = A::One;
+ let b = B::One;
+ match (a, b) {
+ $0(A::One, B::One) => todo!(),
+ (A::One, B::Two) => todo!(),
+ (A::Two, B::One) => todo!(),
+ (A::Two, B::Two) => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_tuple_of_enum_ref() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { One, Two }
+enum B { One, Two }
+
+fn main() {
+ let a = A::One;
+ let b = B::One;
+ match (&a$0, &b) {}
+}
+"#,
+ r#"
+enum A { One, Two }
+enum B { One, Two }
+
+fn main() {
+ let a = A::One;
+ let b = B::One;
+ match (&a, &b) {
+ $0(A::One, B::One) => todo!(),
+ (A::One, B::Two) => todo!(),
+ (A::Two, B::One) => todo!(),
+ (A::Two, B::Two) => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_tuple_of_enum_partial() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { One, Two }
+enum B { One, Two }
+
+fn main() {
+ let a = A::One;
+ let b = B::One;
+ match (a$0, b) {
+ (A::Two, B::One) => {}
+ }
+}
+"#,
+ r#"
+enum A { One, Two }
+enum B { One, Two }
+
+fn main() {
+ let a = A::One;
+ let b = B::One;
+ match (a, b) {
+ (A::Two, B::One) => {}
+ $0(A::One, B::One) => todo!(),
+ (A::One, B::Two) => todo!(),
+ (A::Two, B::Two) => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_tuple_of_enum_partial_with_wildcards() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+//- minicore: option
+fn main() {
+ let a = Some(1);
+ let b = Some(());
+ match (a$0, b) {
+ (Some(_), _) => {}
+ (None, Some(_)) => {}
+ }
+}
+"#,
+ r#"
+fn main() {
+ let a = Some(1);
+ let b = Some(());
+ match (a, b) {
+ (Some(_), _) => {}
+ (None, Some(_)) => {}
+ $0(None, None) => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_partial_with_deep_pattern() {
+ // Fixme: cannot handle deep patterns
+ check_assist_not_applicable(
+ add_missing_match_arms,
+ r#"
+//- minicore: option
+fn main() {
+ match $0Some(true) {
+ Some(true) => {}
+ None => {}
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_tuple_of_enum_not_applicable() {
+ check_assist_not_applicable(
+ add_missing_match_arms,
+ r#"
+enum A { One, Two }
+enum B { One, Two }
+
+fn main() {
+ let a = A::One;
+ let b = B::One;
+ match (a$0, b) {
+ (A::Two, B::One) => {}
+ (A::One, B::One) => {}
+ (A::One, B::Two) => {}
+ (A::Two, B::Two) => {}
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_single_element_tuple_of_enum() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { One, Two }
+
+fn main() {
+ let a = A::One;
+ match (a$0, ) {
+ }
+}
+"#,
+ r#"
+enum A { One, Two }
+
+fn main() {
+ let a = A::One;
+ match (a, ) {
+ $0(A::One,) => todo!(),
+ (A::Two,) => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn test_fill_match_arm_refs() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { As }
+
+fn foo(a: &A) {
+ match a$0 {
+ }
+}
+"#,
+ r#"
+enum A { As }
+
+fn foo(a: &A) {
+ match a {
+ $0A::As => todo!(),
+ }
+}
+"#,
+ );
+
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A {
+ Es { x: usize, y: usize }
+}
+
+fn foo(a: &mut A) {
+ match a$0 {
+ }
+}
+"#,
+ r#"
+enum A {
+ Es { x: usize, y: usize }
+}
+
+fn foo(a: &mut A) {
+ match a {
+ $0A::Es { x, y } => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_target() {
+ check_assist_target(
+ add_missing_match_arms,
+ r#"
+enum E { X, Y }
+
+fn main() {
+ match E::X$0 {}
+}
+"#,
+ "match E::X {}",
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_trivial_arm() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum E { X, Y }
+
+fn main() {
+ match E::X {
+ $0_ => {}
+ }
+}
+"#,
+ r#"
+enum E { X, Y }
+
+fn main() {
+ match E::X {
+ $0E::X => todo!(),
+ E::Y => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_qualifies_path() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+mod foo { pub enum E { X, Y } }
+use foo::E::X;
+
+fn main() {
+ match X {
+ $0
+ }
+}
+"#,
+ r#"
+mod foo { pub enum E { X, Y } }
+use foo::E::X;
+
+fn main() {
+ match X {
+ $0X => todo!(),
+ foo::E::Y => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_preserves_comments() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { One, Two }
+fn foo(a: A) {
+ match a {
+ // foo bar baz$0
+ A::One => {}
+ // This is where the rest should be
+ }
+}
+"#,
+ r#"
+enum A { One, Two }
+fn foo(a: A) {
+ match a {
+ // foo bar baz
+ A::One => {}
+ $0A::Two => todo!(),
+ // This is where the rest should be
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_preserves_comments_empty() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { One, Two }
+fn foo(a: A) {
+ match a {
+ // foo bar baz$0
+ }
+}
+"#,
+ r#"
+enum A { One, Two }
+fn foo(a: A) {
+ match a {
+ $0A::One => todo!(),
+ A::Two => todo!(),
+ // foo bar baz
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn add_missing_match_arms_placeholder() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+enum A { One, Two, }
+fn foo(a: A) {
+ match a$0 {
+ _ => (),
+ }
+}
+"#,
+ r#"
+enum A { One, Two, }
+fn foo(a: A) {
+ match a {
+ $0A::One => todo!(),
+ A::Two => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn option_order() {
+ cov_mark::check!(option_order);
+ check_assist(
+ add_missing_match_arms,
+ r#"
+//- minicore: option
+fn foo(opt: Option<i32>) {
+ match opt$0 {
+ }
+}
+"#,
+ r#"
+fn foo(opt: Option<i32>) {
+ match opt {
+ Some(${0:_}) => todo!(),
+ None => todo!(),
+ }
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn works_inside_macro_call() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+macro_rules! m { ($expr:expr) => {$expr}}
+enum Test {
+ A,
+ B,
+ C,
+}
+
+fn foo(t: Test) {
+ m!(match t$0 {});
+}"#,
+ r#"
+macro_rules! m { ($expr:expr) => {$expr}}
+enum Test {
+ A,
+ B,
+ C,
+}
+
+fn foo(t: Test) {
+ m!(match t {
+ $0Test::A => todo!(),
+ Test::B => todo!(),
+ Test::C => todo!(),
+});
+}"#,
+ );
+ }
+
+ #[test]
+ fn lazy_computation() {
+ // Computing a single missing arm is enough to determine applicability of the assist.
+ cov_mark::check_count!(add_missing_match_arms_lazy_computation, 1);
+ check_assist_unresolved(
+ add_missing_match_arms,
+ r#"
+enum A { One, Two, }
+fn foo(tuple: (A, A)) {
+ match $0tuple {};
+}
+"#,
+ );
+ }
+
+ #[test]
+ fn adds_comma_before_new_arms() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+fn foo(t: bool) {
+ match $0t {
+ true => 1 + 2
+ }
+}"#,
+ r#"
+fn foo(t: bool) {
+ match t {
+ true => 1 + 2,
+ $0false => todo!(),
+ }
+}"#,
+ );
+ }
+
+ #[test]
+ fn does_not_add_extra_comma() {
+ check_assist(
+ add_missing_match_arms,
+ r#"
+fn foo(t: bool) {
+ match $0t {
+ true => 1 + 2,
+ }
+}"#,
+ r#"
+fn foo(t: bool) {
+ match t {
+ true => 1 + 2,
+ $0false => todo!(),
+ }
+}"#,
+ );
+ }
+
+ #[test]
+ fn does_not_remove_catch_all_with_non_empty_expr() {
+ cov_mark::check!(add_missing_match_arms_empty_expr);
+ check_assist(
+ add_missing_match_arms,
+ r#"
+fn foo(t: bool) {
+ match $0t {
+ _ => 1 + 2,
+ }
+}"#,
+ r#"
+fn foo(t: bool) {
+ match t {
+ _ => 1 + 2,
+ $0true => todo!(),
+ false => todo!(),
+ }
+}"#,
+ );
+ }
+}