document some more assists

6 files changed, 279 insertions, 90 deletions

diff --git a/crates/ra_assists/src/assists/merge_match_arms.rs b/crates/ra_assists/src/assists/merge_match_arms.rs
index 17baa98f9..f5ddd7159 100644
--- a/crates/ra_assists/src/assists/merge_match_arms.rs
+++ b/crates/ra_assists/src/assists/merge_match_arms.rs
@@ -1,9 +1,31 @@
-//! FIXME: write short doc here
-
 use crate::{Assist, AssistCtx, AssistId, TextRange, TextUnit};
 use hir::db::HirDatabase;
 use ra_syntax::ast::{AstNode, MatchArm};
 
+// Assist: merge_match_arms
+//
+// Merges identical match arms.
+//
+// ```
+// enum Action { Move { distance: u32 }, Stop }
+//
+// fn handle(action: Action) {
+//     match action {
+//         <|>Action::Move(..) => foo(),
+//         Action::Stop => foo(),
+//     }
+// }
+// ```
+// ->
+// ```
+// enum Action { Move { distance: u32 }, Stop }
+//
+// fn handle(action: Action) {
+//     match action {
+//         Action::Move(..) | Action::Stop => foo(),
+//     }
+// }
+// ```
 pub(crate) fn merge_match_arms(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
     let current_arm = ctx.node_at_offset::<MatchArm>()?;
 
diff --git a/crates/ra_assists/src/assists/move_bounds.rs b/crates/ra_assists/src/assists/move_bounds.rs
index d2444b6b9..f96e19a9f 100644
--- a/crates/ra_assists/src/assists/move_bounds.rs
+++ b/crates/ra_assists/src/assists/move_bounds.rs
@@ -1,5 +1,3 @@
-//! FIXME: write short doc here
-
 use hir::db::HirDatabase;
 use ra_syntax::{
     ast::{self, edit, make, AstNode, NameOwner, TypeBoundsOwner},
@@ -9,6 +7,21 @@ use ra_syntax::{
 
 use crate::{Assist, AssistCtx, AssistId};
 
+// Assist: move_bounds_to_where_clause
+//
+// Moves inline type bounds to a where clause.
+//
+// ```
+// fn apply<T, U, <|>F: FnOnce(T) -> U>(f: F, x: T) -> U {
+//     f(x)
+// }
+// ```
+// ->
+// ```
+// fn apply<T, U, F>(f: F, x: T) -> U where F: FnOnce(T) -> U {
+//     f(x)
+// }
+// ```
 pub(crate) fn move_bounds_to_where_clause(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
     let type_param_list = ctx.node_at_offset::<ast::TypeParamList>()?;
 
diff --git a/crates/ra_assists/src/assists/move_guard.rs b/crates/ra_assists/src/assists/move_guard.rs
index 51aea6334..36c95128d 100644
--- a/crates/ra_assists/src/assists/move_guard.rs
+++ b/crates/ra_assists/src/assists/move_guard.rs
@@ -1,5 +1,3 @@
-//! FIXME: write short doc here
-
 use hir::db::HirDatabase;
 use ra_syntax::{
     ast,
@@ -9,6 +7,31 @@ use ra_syntax::{
 
 use crate::{Assist, AssistCtx, AssistId};
 
+// Assist: move_guard_to_arm_body
+//
+// Moves match guard into match arm body.
+//
+// ```
+// enum Action { Move { distance: u32 }, Stop }
+//
+// fn handle(action: Action) {
+//     match action {
+//         Action::Move { distance } <|>if distance > 10 => foo(),
+//         _ => (),
+//     }
+// }
+// ```
+// ->
+// ```
+// enum Action { Move { distance: u32 }, Stop }
+//
+// fn handle(action: Action) {
+//     match action {
+//         Action::Move { distance } => if distance > 10 { foo() },
+//         _ => (),
+//     }
+// }
+// ```
 pub(crate) fn move_guard_to_arm_body(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
     let match_arm = ctx.node_at_offset::<MatchArm>()?;
     let guard = match_arm.guard()?;
@@ -42,6 +65,31 @@ pub(crate) fn move_guard_to_arm_body(mut ctx: AssistCtx<impl HirDatabase>) -> Op
     ctx.build()
 }
 
+// Assist: move_arm_cond_to_match_guard
+//
+// Moves if expression from match arm body into a guard.
+//
+// ```
+// enum Action { Move { distance: u32 }, Stop }
+//
+// fn handle(action: Action) {
+//     match action {
+//         Action::Move { distance } => <|>if distance > 10 { foo() },
+//         _ => (),
+//     }
+// }
+// ```
+// ->
+// ```
+// enum Action { Move { distance: u32 }, Stop }
+//
+// fn handle(action: Action) {
+//     match action {
+//         Action::Move { distance } if distance > 10 => foo(),
+//         _ => (),
+//     }
+// }
+// ```
 pub(crate) fn move_arm_cond_to_match_guard(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
     let match_arm: MatchArm = ctx.node_at_offset::<MatchArm>()?;
     let last_match_pat = match_arm.pats().last()?;
diff --git a/crates/ra_assists/src/doc_tests/generated.rs b/crates/ra_assists/src/doc_tests/generated.rs
index b96d5772e..09677af68 100644
--- a/crates/ra_assists/src/doc_tests/generated.rs
+++ b/crates/ra_assists/src/doc_tests/generated.rs
@@ -273,3 +273,100 @@ fn main() {
 "#####,
     )
 }
+
+#[test]
+fn doctest_merge_match_arms() {
+    check(
+        "merge_match_arms",
+        r#####"
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        <|>Action::Move(..) => foo(),
+        Action::Stop => foo(),
+    }
+}
+"#####,
+        r#####"
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move(..) | Action::Stop => foo(),
+    }
+}
+"#####,
+    )
+}
+
+#[test]
+fn doctest_move_arm_cond_to_match_guard() {
+    check(
+        "move_arm_cond_to_match_guard",
+        r#####"
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move { distance } => <|>if distance > 10 { foo() },
+        _ => (),
+    }
+}
+"#####,
+        r#####"
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move { distance } if distance > 10 => foo(),
+        _ => (),
+    }
+}
+"#####,
+    )
+}
+
+#[test]
+fn doctest_move_bounds_to_where_clause() {
+    check(
+        "move_bounds_to_where_clause",
+        r#####"
+fn apply<T, U, <|>F: FnOnce(T) -> U>(f: F, x: T) -> U {
+    f(x)
+}
+"#####,
+        r#####"
+fn apply<T, U, F>(f: F, x: T) -> U where F: FnOnce(T) -> U {
+    f(x)
+}
+"#####,
+    )
+}
+
+#[test]
+fn doctest_move_guard_to_arm_body() {
+    check(
+        "move_guard_to_arm_body",
+        r#####"
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move { distance } <|>if distance > 10 => foo(),
+        _ => (),
+    }
+}
+"#####,
+        r#####"
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move { distance } => if distance > 10 { foo() },
+        _ => (),
+    }
+}
+"#####,
+    )
+}
diff --git a/docs/user/assists.md b/docs/user/assists.md
index ee1cfa142..34a95696c 100644
--- a/docs/user/assists.md
+++ b/docs/user/assists.md
@@ -265,3 +265,96 @@ fn main() {
     var_name * 4;
 }
 ```
+
+## `merge_match_arms`
+
+Merges identical match arms.
+
+```rust
+// BEFORE
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        ┃Action::Move(..) => foo(),
+        Action::Stop => foo(),
+    }
+}
+
+// AFTER
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move(..) | Action::Stop => foo(),
+    }
+}
+```
+
+## `move_arm_cond_to_match_guard`
+
+Moves if expression from match arm body into a guard.
+
+```rust
+// BEFORE
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move { distance } => ┃if distance > 10 { foo() },
+        _ => (),
+    }
+}
+
+// AFTER
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move { distance } if distance > 10 => foo(),
+        _ => (),
+    }
+}
+```
+
+## `move_bounds_to_where_clause`
+
+Moves inline type bounds to a where clause.
+
+```rust
+// BEFORE
+fn apply<T, U, ┃F: FnOnce(T) -> U>(f: F, x: T) -> U {
+    f(x)
+}
+
+// AFTER
+fn apply<T, U, F>(f: F, x: T) -> U where F: FnOnce(T) -> U {
+    f(x)
+}
+```
+
+## `move_guard_to_arm_body`
+
+Moves match guard into match arm body.
+
+```rust
+// BEFORE
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move { distance } ┃if distance > 10 => foo(),
+        _ => (),
+    }
+}
+
+// AFTER
+enum Action { Move { distance: u32 }, Stop }
+
+fn handle(action: Action) {
+    match action {
+        Action::Move { distance } => if distance > 10 { foo() },
+        _ => (),
+    }
+}
+```
diff --git a/docs/user/features.md b/docs/user/features.md
index 39dab710d..2e213e34c 100644
--- a/docs/user/features.md
+++ b/docs/user/features.md
@@ -154,45 +154,6 @@ fn main() {
 }
 ```
 
-- Flip `,`
-
-```rust
-// before:
-fn foo(x: usize,<|> dim: (usize, usize)) {}
-// after:
-fn foo(dim: (usize, usize), x: usize) {}
-```
-
-- Introduce variable:
-
-```rust
-// before:
-fn foo() {
-    foo(<|>1 + 1<|>);
-}
-
-// after:
-fn foo() {
-    let var_name = 1 + 1;
-    foo(var_name);
-}
-```
-
-- Inline local variable:
-
-```rust
-// before:
-fn foo() {
-    let a<|> = 1 + 1;
-    let b = a * 10;
-}
-
-// after:
-fn foo() {
-    let b = (1 + 1) * 10;
-}
-```
-
 - Remove `dbg!`
 
 ```rust
@@ -245,41 +206,6 @@ use crate:<|>:db::{RootDatabase, FileSymbol};
 use crate::{<|>db::{RootDatabase, FileSymbol}};
 ```
 
-- Flip binary expression
-
-```rust
-// before:
-fn foo() {
-    if 1 <<|> 2 {
-        println!("Who would have thought?");
-    }
-}
-// after:
-fn foo() {
-    if 2 ><|> 1 {
-        println!("Who would have thought?");
-    }
-}
-```
-
-- Move guard expression to match arm body
-```rust
-// before:
-fn f() {
-    match x {
-        <|>y @ 4 | y @ 5    if y > 5 => true,
-        _ => false
-    }
-}
-// after:
-fn f() {
-    match x {
-        y @ 4 | y @ 5 => if y > 5 { <|>true },
-        _ => false
-    }
-}
-```
-
 - Move if condition to match arm guard
 ```rust
 // before:
@@ -309,16 +235,6 @@ fn f() {
 }
 ```
 
-- Move type bounds to where clause
-
-```rust
-// before:
-fn foo<T: u32, F: FnOnce(T) -> T>() {}
-
-// after:
-fn foo<T, F>() where T: u32, F: FnOnce(T) -> T {}
-```
-
 - Make raw string unescaped
 
 ```rust