Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-assists/src/handlers/invert_if.rs')
| -rw-r--r-- | crates/ide-assists/src/handlers/invert_if.rs | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/crates/ide-assists/src/handlers/invert_if.rs b/crates/ide-assists/src/handlers/invert_if.rs new file mode 100644 index 0000000000..6eed59c9ea --- /dev/null +++ b/crates/ide-assists/src/handlers/invert_if.rs @@ -0,0 +1,144 @@ +use ide_db::syntax_helpers::node_ext::is_pattern_cond; +use syntax::{ + ast::{self, AstNode}, + T, +}; + +use crate::{ + assist_context::{AssistContext, Assists}, + utils::invert_boolean_expression, + AssistId, AssistKind, +}; + +// Assist: invert_if +// +// This transforms if expressions of the form `if !x {A} else {B}` into `if x {B} else {A}` +// This also works with `!=`. This assist can only be applied with the cursor on `if`. +// +// ``` +// fn main() { +// if$0 !y { A } else { B } +// } +// ``` +// -> +// ``` +// fn main() { +// if y { B } else { A } +// } +// ``` +pub(crate) fn invert_if(acc: &mut Assists, ctx: &AssistContext) -> Option<()> { + let if_keyword = ctx.find_token_syntax_at_offset(T![if])?; + let expr = ast::IfExpr::cast(if_keyword.parent()?)?; + let if_range = if_keyword.text_range(); + let cursor_in_range = if_range.contains_range(ctx.selection_trimmed()); + if !cursor_in_range { + return None; + } + + let cond = expr.condition()?; + // This assist should not apply for if-let. + if is_pattern_cond(cond.clone()) { + return None; + } + + let then_node = expr.then_branch()?.syntax().clone(); + let else_block = match expr.else_branch()? { + ast::ElseBranch::Block(it) => it, + ast::ElseBranch::IfExpr(_) => return None, + }; + + acc.add(AssistId("invert_if", AssistKind::RefactorRewrite), "Invert if", if_range, |edit| { + let flip_cond = invert_boolean_expression(cond.clone()); + edit.replace_ast(cond, flip_cond); + + let else_node = else_block.syntax(); + let else_range = else_node.text_range(); + let then_range = then_node.text_range(); + + edit.replace(else_range, then_node.text()); + edit.replace(then_range, else_node.text()); + }) +} + +#[cfg(test)] +mod tests { + use super::*; + + use crate::tests::{check_assist, check_assist_not_applicable}; + + #[test] + fn invert_if_composite_condition() { + check_assist( + invert_if, + "fn f() { i$0f x == 3 || x == 4 || x == 5 { 1 } else { 3 * 2 } }", + "fn f() { if !(x == 3 || x == 4 || x == 5) { 3 * 2 } else { 1 } }", + ) + } + + #[test] + fn invert_if_remove_not_parentheses() { + check_assist( + invert_if, + "fn f() { i$0f !(x == 3 || x == 4 || x == 5) { 3 * 2 } else { 1 } }", + "fn f() { if x == 3 || x == 4 || x == 5 { 1 } else { 3 * 2 } }", + ) + } + + #[test] + fn invert_if_remove_inequality() { + check_assist( + invert_if, + "fn f() { i$0f x != 3 { 1 } else { 3 + 2 } }", + "fn f() { if x == 3 { 3 + 2 } else { 1 } }", + ) + } + + #[test] + fn invert_if_remove_not() { + check_assist( + invert_if, + "fn f() { $0if !cond { 3 * 2 } else { 1 } }", + "fn f() { if cond { 1 } else { 3 * 2 } }", + ) + } + + #[test] + fn invert_if_general_case() { + check_assist( + invert_if, + "fn f() { i$0f cond { 3 * 2 } else { 1 } }", + "fn f() { if !cond { 1 } else { 3 * 2 } }", + ) + } + + #[test] + fn invert_if_doesnt_apply_with_cursor_not_on_if() { + check_assist_not_applicable(invert_if, "fn f() { if !$0cond { 3 * 2 } else { 1 } }") + } + + #[test] + fn invert_if_doesnt_apply_with_if_let() { + check_assist_not_applicable( + invert_if, + "fn f() { i$0f let Some(_) = Some(1) { 1 } else { 0 } }", + ) + } + + #[test] + fn invert_if_option_case() { + check_assist( + invert_if, + "fn f() { if$0 doc_style.is_some() { Class::DocComment } else { Class::Comment } }", + "fn f() { if doc_style.is_none() { Class::Comment } else { Class::DocComment } }", + ) + } + + #[test] + fn invert_if_result_case() { + check_assist( + invert_if, + "fn f() { i$0f doc_style.is_err() { Class::Err } else { Class::Ok } }", + "fn f() { if doc_style.is_ok() { Class::Ok } else { Class::Err } }", + ) + } +} |