Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-assists/src/handlers/merge_nested_if.rs')
| -rw-r--r-- | crates/ide-assists/src/handlers/merge_nested_if.rs | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/crates/ide-assists/src/handlers/merge_nested_if.rs b/crates/ide-assists/src/handlers/merge_nested_if.rs new file mode 100644 index 0000000000..2f3136f027 --- /dev/null +++ b/crates/ide-assists/src/handlers/merge_nested_if.rs @@ -0,0 +1,246 @@ +use ide_db::syntax_helpers::node_ext::is_pattern_cond; +use syntax::{ + ast::{self, AstNode, BinaryOp}, + T, +}; + +use crate::{ + assist_context::{AssistContext, Assists}, + AssistId, AssistKind, +}; +// Assist: merge_nested_if +// +// This transforms if expressions of the form `if x { if y {A} }` into `if x && y {A}` +// This assist can only be applied with the cursor on `if`. +// +// ``` +// fn main() { +// i$0f x == 3 { if y == 4 { 1 } } +// } +// ``` +// -> +// ``` +// fn main() { +// if x == 3 && y == 4 { 1 } +// } +// ``` +pub(crate) fn merge_nested_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; + } + + //should not apply to if with else branch. + if expr.else_branch().is_some() { + return None; + } + + let cond = expr.condition()?; + //should not apply for if-let + if is_pattern_cond(cond.clone()) { + return None; + } + + let cond_range = cond.syntax().text_range(); + + //check if the then branch is a nested if + let then_branch = expr.then_branch()?; + let stmt = then_branch.stmt_list()?; + if stmt.statements().count() != 0 { + return None; + } + + let nested_if_to_merge = then_branch.tail_expr().and_then(|e| match e { + ast::Expr::IfExpr(e) => Some(e), + _ => None, + })?; + // should not apply to nested if with else branch. + if nested_if_to_merge.else_branch().is_some() { + return None; + } + let nested_if_cond = nested_if_to_merge.condition()?; + if is_pattern_cond(nested_if_cond.clone()) { + return None; + } + + let nested_if_then_branch = nested_if_to_merge.then_branch()?; + let then_branch_range = then_branch.syntax().text_range(); + + acc.add( + AssistId("merge_nested_if", AssistKind::RefactorRewrite), + "Merge nested if", + if_range, + |edit| { + let cond_text = if has_logic_op_or(&cond) { + format!("({})", cond.syntax().text()) + } else { + cond.syntax().text().to_string() + }; + + let nested_if_cond_text = if has_logic_op_or(&nested_if_cond) { + format!("({})", nested_if_cond.syntax().text()) + } else { + nested_if_cond.syntax().text().to_string() + }; + + let replace_cond = format!("{} && {}", cond_text, nested_if_cond_text); + + edit.replace(cond_range, replace_cond); + edit.replace(then_branch_range, nested_if_then_branch.syntax().text()); + }, + ) +} + +/// Returns whether the given if condition has logical operators. +fn has_logic_op_or(expr: &ast::Expr) -> bool { + match expr { + ast::Expr::BinExpr(bin_expr) => { + if let Some(kind) = bin_expr.op_kind() { + matches!(kind, BinaryOp::LogicOp(ast::LogicOp::Or)) + } else { + false + } + } + _ => false, + } +} + +#[cfg(test)] +mod tests { + use super::*; + use crate::tests::{check_assist, check_assist_not_applicable}; + + #[test] + fn merge_nested_if_test1() { + check_assist( + merge_nested_if, + "fn f() { i$0f x == 3 { if y == 4 { 1 } } }", + "fn f() { if x == 3 && y == 4 { 1 } }", + ) + } + + #[test] + fn merge_nested_if_test2() { + check_assist( + merge_nested_if, + "fn f() { i$0f x == 3 || y == 1 { if z == 4 { 1 } } }", + "fn f() { if (x == 3 || y == 1) && z == 4 { 1 } }", + ) + } + + #[test] + fn merge_nested_if_test3() { + check_assist( + merge_nested_if, + "fn f() { i$0f x == 3 && y == 1 { if z == 4 { 1 } } }", + "fn f() { if x == 3 && y == 1 && z == 4 { 1 } }", + ) + } + + #[test] + fn merge_nested_if_test4() { + check_assist( + merge_nested_if, + "fn f() { i$0f x == 3 && y == 1 { if z == 4 && q == 3 { 1 } } }", + "fn f() { if x == 3 && y == 1 && z == 4 && q == 3 { 1 } }", + ) + } + + #[test] + fn merge_nested_if_test5() { + check_assist( + merge_nested_if, + "fn f() { i$0f x == 3 && y == 1 { if z == 4 || q == 3 { 1 } } }", + "fn f() { if x == 3 && y == 1 && (z == 4 || q == 3) { 1 } }", + ) + } + + #[test] + fn merge_nested_if_test6() { + check_assist( + merge_nested_if, + "fn f() { i$0f x == 3 || y == 1 { if z == 4 || q == 3 { 1 } } }", + "fn f() { if (x == 3 || y == 1) && (z == 4 || q == 3) { 1 } }", + ) + } + + #[test] + fn merge_nested_if_test7() { + check_assist( + merge_nested_if, + "fn f() { i$0f x == 3 || y == 1 { if z == 4 && q == 3 { 1 } } }", + "fn f() { if (x == 3 || y == 1) && z == 4 && q == 3 { 1 } }", + ) + } + + #[test] + fn merge_nested_if_do_not_apply_to_if_with_else_branch() { + check_assist_not_applicable( + merge_nested_if, + "fn f() { i$0f x == 3 { if y == 4 { 1 } } else { 2 } }", + ) + } + + #[test] + fn merge_nested_if_do_not_apply_to_nested_if_with_else_branch() { + check_assist_not_applicable( + merge_nested_if, + "fn f() { i$0f x == 3 { if y == 4 { 1 } else { 2 } } }", + ) + } + + #[test] + fn merge_nested_if_do_not_apply_to_if_let() { + check_assist_not_applicable( + merge_nested_if, + "fn f() { i$0f let Some(x) = y { if x == 4 { 1 } } }", + ) + } + + #[test] + fn merge_nested_if_do_not_apply_to_nested_if_let() { + check_assist_not_applicable( + merge_nested_if, + "fn f() { i$0f y == 0 { if let Some(x) = y { 1 } } }", + ) + } + + #[test] + fn merge_nested_if_do_not_apply_to_if_with_else_branch_and_nested_if() { + check_assist_not_applicable( + merge_nested_if, + "fn f() { i$0f x == 3 { if y == 4 { 1 } } else { if z == 5 { 2 } } }", + ) + } + + #[test] + fn merge_nested_if_do_not_apply_with_cursor_not_on_if() { + check_assist_not_applicable(merge_nested_if, "fn f() { if $0x==0 { if y == 3 { 1 } } }") + } + + #[test] + fn merge_nested_if_do_not_apply_with_mulpiple_if() { + check_assist_not_applicable( + merge_nested_if, + "fn f() { i$0f x == 0 { if y == 3 { 1 } else if y == 4 { 2 } } }", + ) + } + #[test] + fn merge_nested_if_do_not_apply_with_not_only_has_nested_if() { + check_assist_not_applicable( + merge_nested_if, + "fn f() { i$0f x == 0 { if y == 3 { foo(); } foo(); } }", + ) + } + + #[test] + fn merge_nested_if_do_not_apply_with_multiply_nested_if() { + check_assist_not_applicable( + merge_nested_if, + "fn f() { i$0f x == 0 { if y == 3 { foo(); } if z == 3 { 2 } } }", + ) + } +} |