DioxusLabs/dioxus · error · syn::Error

Expected a single statement in the if block

Error message

Expected a single statement in the if block

What it means

Error "Expected a single statement in the if block" thrown in DioxusLabs/dioxus.

Source

Thrown at packages/rsx/src/attribute.rs:636

            match expr {
                AttributeValue::IfExpr(if_expr) => if_expr.contains_expression(),
                AttributeValue::AttrLiteral(_) => false,
                _ => true,
            }
        }

        attribute_value_contains_expression(&self.then_value)
            || self
                .else_value
                .as_deref()
                .is_some_and(attribute_value_contains_expression)
    }

    fn parse_attribute_value_from_block(block: &Block) -> syn::Result<Box<AttributeValue>> {
        let stmts = &block.stmts;

        if stmts.len() != 1 {
            return Err(syn::Error::new(
                block.span(),
                "Expected a single statement in the if block",
            ));
        }

        // either an ifmt or an expr in the block
        let stmt = &stmts[0];

        // Either it's a valid ifmt or an expression
        match stmt {
            syn::Stmt::Expr(exp, None) => {
                // Try parsing the statement as an IfmtInput by passing it through tokens
                let value: Result<HotLiteral, syn::Error> = syn::parse2(exp.to_token_stream());
                Ok(match value {
                    Ok(res) => Box::new(AttributeValue::AttrLiteral(res)),
                    Err(_) => Box::new(AttributeValue::AttrExpr(PartialExpr::from_expr(exp))),
                })
            }

View on GitHub (pinned to 393d190a80)

When it happens

Trigger: Thrown at packages/rsx/src/attribute.rs:636 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of DioxusLabs/dioxus@393d190a80 (2026-08-16). Data as JSON: /api/errors/6163ff42f263a389. Report an issue: GitHub.