vrl/compiler/expression/

op.rs

use std::fmt;

use crate::compiler::state::{TypeInfo, TypeState};
use crate::compiler::{
    Context, Expression, TypeDef,
    expression::{self, Expr, Resolved},
    parser::{Node, ast},
    value::VrlValueArithmetic,
};
use crate::diagnostic::{DiagnosticMessage, Label, Note, Span, Urls};
use crate::value::Value;

#[derive(Clone, PartialEq)]
pub struct Op {
    pub(crate) lhs: Box<Expr>,
    pub(crate) rhs: Box<Expr>,
    pub(crate) opcode: ast::Opcode,
}

impl Op {
    /// Creates a new `Op` expression.
    ///
    /// # Arguments
    /// * `lhs` - The left-hand side expression.
    /// * `opcode` - The operator to apply.
    /// * `rhs` - The right-hand side expression.
    /// * `state` - The current type state.
    ///
    /// # Returns
    /// A `Result` containing the new `Op` expression or an error.
    ///
    /// # Errors
    /// - `ChainedComparison`: If the left-hand side expression is already a comparison operation.
    /// - `UnnecessaryCoalesce`: If the left-hand side expression is infallible and the operator is `Err`.
    /// - `MergeNonObjects`: If the operator is `Merge` and either operand is not an object.
    pub fn new(
        lhs: Node<Expr>,
        opcode: Node<ast::Opcode>,
        rhs: Node<Expr>,
        state: &TypeState,
    ) -> Result<Self, Error> {
        use ast::Opcode::{Eq, Ge, Gt, Le, Lt, Ne};

        let mut state = state.clone();

        let (op_span, opcode) = opcode.take();

        let (lhs_span, lhs) = lhs.take();
        let lhs_type_def = lhs.apply_type_info(&mut state);
        let rhs_type_def = rhs.apply_type_info(&mut state);

        let (rhs_span, rhs) = rhs.take();

        if matches!(opcode, Eq | Ne | Lt | Le | Gt | Ge)
            && let Expr::Op(op) = &lhs
            && matches!(op.opcode, Eq | Ne | Lt | Le | Gt | Ge)
        {
            return Err(Error::ChainedComparison { span: op_span });
        }

        if let ast::Opcode::Err = opcode
            && lhs_type_def.is_infallible()
        {
            return Err(Error::UnnecessaryCoalesce {
                lhs_span,
                rhs_span,
                op_span,
            });
        }

        if let ast::Opcode::Merge = opcode
            && !(lhs_type_def.is_object() && rhs_type_def.is_object())
        {
            return Err(Error::MergeNonObjects {
                lhs_span: if lhs_type_def.is_object() {
                    None
                } else {
                    Some(lhs_span)
                },
                rhs_span: if rhs_type_def.is_object() {
                    None
                } else {
                    Some(rhs_span)
                },
            });
        }

        Ok(Op {
            lhs: Box::new(lhs),
            rhs: Box::new(rhs),
            opcode,
        })
    }
}

impl Expression for Op {
    fn resolve(&self, ctx: &mut Context) -> Resolved {
        use crate::value::Value::{Boolean, Null};
        use ast::Opcode::{Add, And, Div, Eq, Err, Ge, Gt, Le, Lt, Merge, Mul, Ne, Or, Sub};

        match self.opcode {
            Err => return self.lhs.resolve(ctx).or_else(|_| self.rhs.resolve(ctx)),
            Or => {
                return self
                    .lhs
                    .resolve(ctx)?
                    .try_or(|| self.rhs.resolve(ctx))
                    .map_err(Into::into);
            }
            And => {
                return match self.lhs.resolve(ctx)? {
                    Null | Boolean(false) => Ok(false.into()),
                    v => v.try_and(self.rhs.resolve(ctx)?).map_err(Into::into),
                };
            }
            _ => (),
        }

        let lhs = self.lhs.resolve(ctx)?;
        let rhs = self.rhs.resolve(ctx)?;

        // Arithmetic that can overflow should wrap
        match self.opcode {
            Mul => lhs.try_mul(rhs),
            Div => lhs.try_div(rhs),
            Add => lhs.try_add(rhs),
            Sub => lhs.try_sub(rhs),
            Eq => Ok(lhs.eq_lossy(&rhs).into()),
            Ne => Ok((!lhs.eq_lossy(&rhs)).into()),
            Gt => lhs.try_gt(rhs),
            Ge => lhs.try_ge(rhs),
            Lt => lhs.try_lt(rhs),
            Le => lhs.try_le(rhs),
            Merge => lhs.try_merge(rhs),
            And | Or | Err => unreachable!(),
        }
        .map_err(Into::into)
    }

    #[allow(clippy::too_many_lines)]
    fn type_info(&self, state: &TypeState) -> TypeInfo {
        use crate::value::Kind as K;
        use ast::Opcode::{Add, And, Div, Eq, Err, Ge, Gt, Le, Lt, Merge, Mul, Ne, Or, Sub};
        let original_state = state.clone();

        let mut state = state.clone();
        let mut lhs_def = self.lhs.apply_type_info(&mut state);
        let lhs_value = self.lhs.resolve_constant(&original_state);

        // TODO: this is incorrect, but matches the existing behavior of the compiler
        // see: https://github.com/vectordotdev/vector/issues/13789
        // and: https://github.com/vectordotdev/vector/issues/13791

        // calculates state for an RHS that may or may not be resolved at runtime
        // This merges the type definitions for state. If it is known at compile-time
        // if the RHS will be resolved, this should not be used
        let maybe_rhs = |state: &mut TypeState| {
            let rhs_info = self.rhs.type_info(state);
            *state = state.clone().merge(rhs_info.state);
            rhs_info.result
        };

        let result = match self.opcode {
            Err => {
                let rhs_def = maybe_rhs(&mut state);

                // entire expression is only fallible if both lhs and rhs were fallible
                let fallible = lhs_def.is_fallible() && rhs_def.is_fallible();

                lhs_def.union(rhs_def).maybe_fallible(fallible)
            }

            Or => {
                if lhs_def.is_null() || lhs_value == Some(Value::Boolean(false)) {
                    // lhs is always "false"
                    self.rhs.apply_type_info(&mut state)
                } else if !(lhs_def.contains_null() || lhs_def.contains_boolean())
                    || lhs_value == Some(Value::Boolean(true))
                {
                    // lhs is always "true"
                    lhs_def
                } else {
                    // not sure if lhs is true/false, merge both

                    // We can remove Null from the lhs since we know that if the lhs is Null
                    // we will be returning the rhs and only the rhs type_def will then be relevant.
                    lhs_def.remove_null();

                    lhs_def.union(maybe_rhs(&mut state))
                }
            }

            // ... | ...
            Merge => lhs_def.merge_overwrite(self.rhs.apply_type_info(&mut state)),

            And => {
                if lhs_def.is_null() || lhs_value == Some(Value::Boolean(false)) {
                    // lhs is always "false"
                    TypeDef::boolean()
                } else if lhs_value == Some(Value::Boolean(true)) {
                    // lhs is always "true"
                    // keep the fallibility of RHS, but change it to a boolean
                    self.rhs.apply_type_info(&mut state).with_kind(K::boolean())
                } else {
                    // unknown if lhs is true or false
                    lhs_def
                        .fallible_unless(K::null().or_boolean())
                        .union(maybe_rhs(&mut state).fallible_unless(K::null().or_boolean()))
                        .with_kind(K::boolean())
                }
            }

            // ... == ...
            // ... != ...
            Eq | Ne => lhs_def
                .union(self.rhs.apply_type_info(&mut state))
                .with_kind(K::boolean()),

            Gt | Ge | Lt | Le => {
                let rhs_def = self.rhs.apply_type_info(&mut state);

                // "b" >  "a"
                // "a" >= "a"
                // "a" <  "b"
                // "b" <= "b"
                // t'2023-05-04T22:22:22.234142Z' >  t'2023-04-04T22:22:22.234142Z'
                // t'2023-05-04T22:22:22.234142Z' >= t'2023-04-04T22:22:22.234142Z'
                // t'2023-05-04T22:22:22.234142Z' <  t'2023-04-04T22:22:22.234142Z'
                // t'2023-05-04T22:22:22.234142Z' <= t'2023-04-04T22:22:22.234142Z'
                if (lhs_def.is_bytes() && rhs_def.is_bytes())
                    || (lhs_def.is_timestamp() && rhs_def.is_timestamp())
                {
                    lhs_def.union(rhs_def).with_kind(K::boolean())
                }
                // ... >  ...
                // ... >= ...
                // ... <  ...
                // ... <= ...
                else {
                    lhs_def
                        .fallible_unless(K::integer().or_float())
                        .union(rhs_def.fallible_unless(K::integer().or_float()))
                        .with_kind(K::boolean())
                }
            }

            // ... / ...
            Div => {
                let td = TypeDef::float();

                // Division is infallible if the rhs is a literal normal float or integer.
                match self.rhs.resolve_constant(&state) {
                    Some(value) if lhs_def.is_float() || lhs_def.is_integer() => match value {
                        Value::Float(v) if v.is_normal() => td.infallible(),
                        Value::Integer(v) if v != 0 => td.infallible(),
                        _ => td.fallible(),
                    },
                    _ => td.fallible(),
                }
            }

            Add | Sub | Mul => {
                // none of these operations short-circuit, so the type of RHS can be applied
                let rhs_def = self.rhs.apply_type_info(&mut state);

                match self.opcode {
                    // "bar" + ...
                    // ... + "bar"
                    Add if lhs_def.is_bytes() || rhs_def.is_bytes() => lhs_def
                        .fallible_unless(K::bytes().or_null())
                        .union(rhs_def.fallible_unless(K::bytes().or_null()))
                        .with_kind(K::bytes()),

                    // ... + 1.0
                    // ... - 1.0
                    // ... * 1.0
                    // ... % 1.0
                    // 1.0 + ...
                    // 1.0 - ...
                    // 1.0 * ...
                    // 1.0 % ...
                    Add | Sub | Mul if lhs_def.is_float() || rhs_def.is_float() => lhs_def
                        .fallible_unless(K::integer().or_float())
                        .union(rhs_def.fallible_unless(K::integer().or_float()))
                        .with_kind(K::float()),

                    // 1 + 1
                    // 1 - 1
                    // 1 * 1
                    // 1 % 1
                    Add | Sub | Mul if lhs_def.is_integer() && rhs_def.is_integer() => {
                        lhs_def.union(rhs_def).with_kind(K::integer())
                    }

                    // "bar" * 1
                    Mul if lhs_def.is_bytes() && rhs_def.is_integer() => {
                        lhs_def.union(rhs_def).with_kind(K::bytes())
                    }

                    // 1 * "bar"
                    Mul if lhs_def.is_integer() && rhs_def.is_bytes() => {
                        lhs_def.union(rhs_def).with_kind(K::bytes())
                    }

                    // ... + ...
                    // ... * ...
                    Add | Mul => lhs_def
                        .union(rhs_def)
                        .fallible()
                        .with_kind(K::bytes().or_integer().or_float()),

                    // ... - ...
                    Sub => lhs_def
                        .union(rhs_def)
                        .fallible()
                        .with_kind(K::integer().or_float()),
                    _ => unreachable!("Add, Sub, or Mul operation not handled"),
                }
            }
        };
        TypeInfo::new(state, result)
    }
}

impl fmt::Display for Op {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{} {} {}", self.lhs, self.opcode, self.rhs)
    }
}

impl fmt::Debug for Op {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "Op({} {} {})", self.lhs, self.opcode, self.rhs)
    }
}

// -----------------------------------------------------------------------------

#[derive(thiserror::Error, Debug)]
pub enum Error {
    #[error("comparison operators can't be chained together")]
    ChainedComparison { span: Span },

    #[error("unnecessary error coalescing operation")]
    UnnecessaryCoalesce {
        lhs_span: Span,
        rhs_span: Span,
        op_span: Span,
    },

    #[error("only objects can be merged")]
    MergeNonObjects {
        lhs_span: Option<Span>,
        rhs_span: Option<Span>,
    },

    #[error("fallible operation")]
    Expr(#[from] expression::ExpressionError),
}

impl DiagnosticMessage for Error {
    fn code(&self) -> usize {
        use Error::{ChainedComparison, Expr, MergeNonObjects, UnnecessaryCoalesce};

        match self {
            ChainedComparison { .. } => 650,
            UnnecessaryCoalesce { .. } => 651,
            MergeNonObjects { .. } => 652,
            Expr(err) => err.code(),
        }
    }

    fn message(&self) -> String {
        use Error::Expr;

        match self {
            Expr(err) => err.message(),
            err => err.to_string(),
        }
    }

    fn labels(&self) -> Vec<Label> {
        use Error::{ChainedComparison, Expr, MergeNonObjects, UnnecessaryCoalesce};

        match self {
            ChainedComparison { span } => vec![Label::primary("", span)],
            UnnecessaryCoalesce {
                lhs_span,
                rhs_span,
                op_span,
            } => vec![
                Label::primary("this expression can't fail", lhs_span),
                Label::context("this expression never resolves", rhs_span),
                Label::context("remove this error coalescing operation", op_span),
            ],
            MergeNonObjects { lhs_span, rhs_span } => {
                let mut labels = Vec::new();
                if let Some(lhs_span) = lhs_span {
                    labels.push(Label::primary(
                        "this expression must resolve to an object",
                        lhs_span,
                    ));
                }
                if let Some(rhs_span) = rhs_span {
                    labels.push(Label::primary(
                        "this expression must resolve to an object",
                        rhs_span,
                    ));
                }

                labels
            }
            Expr(err) => err.labels(),
        }
    }

    fn notes(&self) -> Vec<Note> {
        use Error::{ChainedComparison, Expr};

        match self {
            ChainedComparison { .. } => vec![Note::SeeDocs(
                "comparisons".to_owned(),
                Urls::expression_docs_url("#comparison"),
            )],
            Expr(err) => err.notes(),
            _ => vec![],
        }
    }
}

// -----------------------------------------------------------------------------

#[cfg(test)]
mod tests {
    use std::convert::TryInto;

    use chrono::Utc;
    use ordered_float::NotNan;

    use ast::{
        Ident,
        Opcode::{Add, And, Div, Eq, Err, Ge, Gt, Le, Lt, Mul, Ne, Or, Sub},
    };

    use crate::compiler::expression::{Block, IfStatement, Literal, Predicate, Variable};
    use crate::test_type_def;

    use super::*;

    #[allow(clippy::needless_pass_by_value)]
    fn op(
        opcode: ast::Opcode,
        lhs: impl TryInto<Literal> + fmt::Debug + Clone,
        rhs: impl TryInto<Literal> + fmt::Debug + Clone,
    ) -> Op {
        let Ok(lhs) = lhs.clone().try_into() else {
            panic!("not a valid lhs expression: {lhs:?}")
        };

        let Ok(rhs) = rhs.clone().try_into() else {
            panic!("not a valid rhs expression: {rhs:?}")
        };

        Op {
            lhs: Box::new(lhs.into()),
            rhs: Box::new(rhs.into()),
            opcode,
        }
    }

    fn f(f: f64) -> NotNan<f64> {
        NotNan::new(f).unwrap()
    }

    test_type_def![
        or_exact {
            expr: |_| op(Or, "foo", true),
            want: TypeDef::bytes(),
        }

        or_null {
            expr: |_| op(Or, (), true),
            want: TypeDef::boolean(),
        }

        multiply_string_integer {
            expr: |_| op(Mul, "foo", 1),
            want: TypeDef::bytes(),
        }

        multiply_integer_string {
            expr: |_| op(Mul, 1, "foo"),
            want: TypeDef::bytes(),
        }

        multiply_float_integer {
            expr: |_| op(Mul, f(1.0), 1),
            want: TypeDef::float(),
        }

        multiply_integer_float {
            expr: |_| op(Mul, 1, f(1.0)),
            want: TypeDef::float(),
        }

        multiply_integer_integer {
            expr: |_| op(Mul, 1, 1),
            want: TypeDef::integer(),
        }

        multiply_other {
            expr: |_| op(Mul, (), ()),
            want: TypeDef::bytes().fallible().or_integer().or_float(),
        }

        add_string_string {
            expr: |_| op(Add, "foo", "bar"),
            want: TypeDef::bytes(),
        }

        add_string_null {
            expr: |_| op(Add, "foo", ()),
            want: TypeDef::bytes(),
        }

        add_null_string {
            expr: |_| op(Add, (), "foo"),
            want: TypeDef::bytes(),
        }

        add_string_bool {
            expr: |_| op(Add, "foo", true),
            want: TypeDef::bytes().fallible(),
        }

        add_float_integer {
            expr: |_| op(Add, f(1.0), 1),
            want: TypeDef::float(),
        }

        add_integer_float {
            expr: |_| op(Add, 1, f(1.0)),
            want: TypeDef::float(),
        }

        add_float_other {
            expr: |_| op(Add, f(1.0), ()),
            want: TypeDef::float().fallible(),
        }

        add_other_float {
            expr: |_| op(Add, (), f(1.0)),
            want: TypeDef::float().fallible(),
        }

        add_integer_integer {
            expr: |_| op(Add, 1, 1),
            want: TypeDef::integer(),
        }

        add_other {
            expr: |_| op(Add, (), ()),
            want: TypeDef::bytes().or_integer().or_float().fallible(),
        }

        subtract_integer {
            expr: |_| op(Sub, 1, 1),
            want: TypeDef::integer().infallible(),
        }

        subtract_float {
            expr: |_| op(Sub, 1.0, 1.0),
            want: TypeDef::float().infallible(),
        }

        subtract_mixed {
            expr: |_| op(Sub, 1, 1.0),
            want: TypeDef::float().infallible(),
        }

        subtract_other {
            expr: |_| op(Sub, 1, ()),
            want: TypeDef::integer().fallible().or_float(),
        }

        divide_integer_literal {
            expr: |_| op(Div, 1, 1),
            want: TypeDef::float().infallible(),
        }

        divide_float_literal {
            expr: |_| op(Div, 1.0, 1.0),
            want: TypeDef::float().infallible(),
        }

        divide_mixed_literal {
            expr: |_| op(Div, 1, 1.0),
            want: TypeDef::float().infallible(),
        }

        divide_float_zero_literal {
            expr: |_| op(Div, 1, 0.0),
            want: TypeDef::float().fallible(),
        }

        divide_integer_zero_literal {
            expr: |_| op(Div, 1, 0),
            want: TypeDef::float().fallible(),
        }

        divide_lhs_literal_wrong_rhs {
            expr: |_| Op {
                lhs: Box::new(Literal::from(true).into()),
                rhs: Box::new(Literal::from(NotNan::new(1.0).unwrap()).into()),
                opcode: Div,
            },
            want: TypeDef::float().fallible(),
        }

        divide_dynamic_rhs {
            expr: |state: &mut TypeState| {
                state.local.insert_variable(Ident::new("foo"), crate::compiler::type_def::Details {
                    type_def: TypeDef::null(),
                    value: None,
                });

                Op {
                    lhs: Box::new(Literal::from(1).into()),
                    rhs: Box::new(Variable::new(Span::default(), Ident::new("foo"), &state.local).unwrap().into()),
                    opcode: Div,
                }
            },
            want: TypeDef::float().fallible(),
        }

        divide_other {
            expr: |_| op(Div, 1.0, ()),
            want: TypeDef::float().fallible(),
        }

        and_null {
            expr: |_| op(And, (), ()),
            want: TypeDef::boolean().infallible(),
        }

        and_boolean {
            expr: |_| op(And, true, true),
            want: TypeDef::boolean().infallible(),
        }

        and_mixed {
            expr: |_| op(And, (), true),
            want: TypeDef::boolean().infallible(),
        }

        and_other {
            expr: |_| op(And, (), "bar"),
            want: TypeDef::boolean().infallible(),
        }

        equal {
            expr: |_| op(Eq, (), ()),
            want: TypeDef::boolean().infallible(),
        }

        not_equal {
            expr: |_| op(Ne, (), "foo"),
            want: TypeDef::boolean().infallible(),
        }

        greater_integer {
            expr: |_| op(Gt, 1, 1),
            want: TypeDef::boolean().infallible(),
        }

        greater_float {
            expr: |_| op(Gt, 1.0, 1.0),
            want: TypeDef::boolean().infallible(),
        }

        greater_mixed {
            expr: |_| op(Gt, 1, 1.0),
            want: TypeDef::boolean().infallible(),
        }

        greater_bytes {
            expr: |_| op(Gt, "c", "b"),
            want: TypeDef::boolean().infallible(),
        }

        greater_timestamps {
            expr: |_| op(Gt, Utc::now(), Utc::now()),
            want: TypeDef::boolean().infallible(),
        }

        greater_other {
            expr: |_| op(Gt, 1, "foo"),
            want: TypeDef::boolean().fallible(),
        }

        greater_or_equal_integer {
            expr: |_| op(Ge, 1, 1),
            want: TypeDef::boolean().infallible(),
        }

        greater_or_equal_float {
            expr: |_| op(Ge, 1.0, 1.0),
            want: TypeDef::boolean().infallible(),
        }

        greater_or_equal_mixed {
            expr: |_| op(Ge, 1, 1.0),
            want: TypeDef::boolean().infallible(),
        }

        greater_or_equal_bytes {
            expr: |_| op(Ge, "foo", "foo"),
            want: TypeDef::boolean().infallible(),
        }

        greater_or_equal_timestamps {
            expr: |_| op(Ge, Utc::now(), Utc::now()),
            want: TypeDef::boolean().infallible(),
        }

        greater_or_equal_other {
            expr: |_| op(Ge, 1, "foo"),
            want: TypeDef::boolean().fallible(),
        }

        less_integer {
            expr: |_| op(Lt, 1, 1),
            want: TypeDef::boolean().infallible(),
        }

        less_float {
            expr: |_| op(Lt, 1.0, 1.0),
            want: TypeDef::boolean().infallible(),
        }

        less_mixed {
            expr: |_| op(Lt, 1, 1.0),
            want: TypeDef::boolean().infallible(),
        }

        less_bytes {
            expr: |_| op(Lt, "bar", "foo"),
            want: TypeDef::boolean().infallible(),
        }

        less_timestamps {
            expr: |_| op(Lt, Utc::now(), Utc::now()),
            want: TypeDef::boolean().infallible(),
        }

        less_other {
            expr: |_| op(Lt, 1, "foo"),
            want: TypeDef::boolean().fallible(),
        }

        less_or_equal_integer {
            expr: |_| op(Le, 1, 1),
            want: TypeDef::boolean().infallible(),
        }

        less_or_equal_float {
            expr: |_| op(Le, 1.0, 1.0),
            want: TypeDef::boolean().infallible(),
        }

        less_or_equal_mixed {
            expr: |_| op(Le, 1, 1.0),
            want: TypeDef::boolean().infallible(),
        }

        less_or_equal_bytes {
            expr: |_| op(Le, "bar", "bar"),
            want: TypeDef::boolean().infallible(),
        }

        less_or_equal_timestamps {
            expr: |_| op(Le, Utc::now(), Utc::now()),
            want: TypeDef::boolean().infallible(),
        }

        less_or_equal_other {
            expr: |_| op(Le, 1, "baz"),
            want: TypeDef::boolean().fallible(),
        }

        error_or_rhs_infallible {
            expr: |_| Op {
                lhs: Box::new(Op {
                    lhs: Box::new(Literal::from("foo").into()),
                    rhs: Box::new(Literal::from(1).into()),
                    opcode: Div,
                }.into()),
                rhs: Box::new(Literal::from(true).into()),
                opcode: Err,
            },
            want: TypeDef::float().or_boolean(),
        }

        error_or_fallible {
            expr: |_| Op {
                lhs: Box::new(Op {
                    lhs: Box::new(Literal::from("foo").into()),
                    rhs: Box::new(Literal::from(NotNan::new(0.0).unwrap()).into()),
                    opcode: Div,
                }.into()),
                rhs: Box::new(Op {
                    lhs: Box::new(Literal::from(true).into()),
                    rhs: Box::new(Literal::from(NotNan::new(0.0).unwrap()).into()),
                    opcode: Div,
                }.into()),
                opcode: Err,
            },
            want: TypeDef::float().fallible(),
        }

        error_or_nested_infallible {
            expr: |_| Op {
                lhs: Box::new(Op {
                    lhs: Box::new(Literal::from("foo").into()),
                    rhs: Box::new(Literal::from(1).into()),
                    opcode: Div,
                }.into()),
                rhs: Box::new(Op {
                    lhs: Box::new(Op {
                        lhs: Box::new(Literal::from(true).into()),
                        rhs: Box::new(Literal::from(1).into()),
                        opcode: Div,
                    }.into()),
                    rhs: Box::new(Literal::from("foo").into()),
                    opcode: Err,
                }.into()),
                opcode: Err,
            },
            want: TypeDef::float().or_bytes(),
        }

        or_nullable {
            expr: |_| Op {
                lhs: Box::new(
                    IfStatement {
                        predicate: Predicate::new_unchecked(vec![Literal::from(true).into()]),
                        if_block: Block::new_scoped(vec![Literal::from("string").into()]),
                        else_block: None,
                    }.into()),
                rhs: Box::new(Literal::from("another string").into()),
                opcode: Or,
            },
            want: TypeDef::bytes(),
        }

        or_not_nullable {
            expr: |_| Op {
                lhs: Box::new(
                    IfStatement {
                        predicate: Predicate::new_unchecked(vec![Literal::from(true).into()]),
                        if_block: Block::new_scoped(vec![Literal::from("string").into()]),
                        else_block:  Some(Block::new_scoped(vec![Literal::from(42).into()]))
                }.into()),
                rhs: Box::new(Literal::from("another string").into()),
                opcode: Or,
            },
            want: TypeDef::bytes().or_integer(),
        }
    ];
}