use ra_syntax::{AstNode, ast}; use ra_ide_api_light::formatting::extract_trivial_expression; use hir::db::HirDatabase; use crate::{AssistCtx, Assist}; pub(crate) fn replace_if_let_with_match(ctx: AssistCtx) -> Option { let if_expr: &ast::IfExpr = ctx.node_at_offset()?; let cond = if_expr.condition()?; let pat = cond.pat()?; let expr = cond.expr()?; let then_block = if_expr.then_branch()?; let else_block = match if_expr.else_branch()? { ast::ElseBranchFlavor::Block(it) => it, ast::ElseBranchFlavor::IfExpr(_) => return None, }; ctx.build("replace with match", |edit| { let match_expr = build_match_expr(expr, pat, then_block, else_block); edit.replace_node_and_indent(if_expr.syntax(), match_expr); edit.set_cursor(if_expr.syntax().range().start()) }) } fn build_match_expr( expr: &ast::Expr, pat1: &ast::Pat, arm1: &ast::Block, arm2: &ast::Block, ) -> String { let mut buf = String::new(); buf.push_str(&format!("match {} {{\n", expr.syntax().text())); buf.push_str(&format!( " {} => {}\n", pat1.syntax().text(), format_arm(arm1) )); buf.push_str(&format!(" _ => {}\n", format_arm(arm2))); buf.push_str("}"); buf } fn format_arm(block: &ast::Block) -> String { match extract_trivial_expression(block) { None => block.syntax().text().to_string(), Some(e) => format!("{},", e.syntax().text()), } } #[cfg(test)] mod tests { use super::*; use crate::helpers::check_assist; #[test] fn test_replace_if_let_with_match_unwraps_simple_expressions() { check_assist( replace_if_let_with_match, " impl VariantData { pub fn is_struct(&self) -> bool { if <|>let VariantData::Struct(..) = *self { true } else { false } } } ", " impl VariantData { pub fn is_struct(&self) -> bool { <|>match *self { VariantData::Struct(..) => true, _ => false, } } } ", ) } }