rib/compiler/

byte_code.rs

use crate::compiler::byte_code::internal::ExprState;
use crate::compiler::ir::RibIR;
use crate::type_inference::TypeHint;
use crate::{Expr, InferredExpr, InstructionId};
use std::fmt::{Display, Formatter};

#[derive(Debug, Clone, Default, PartialEq)]
pub struct RibByteCode {
    pub instructions: Vec<RibIR>,
}

#[derive(Debug, Clone, PartialEq)]
pub enum RibByteCodeGenerationError {
    CastError(String),
    AnalysedTypeConversionError(String),
    PatternMatchDesugarError,
    RangeSelectionDesugarError(String),
    UnexpectedTypeError {
        expected: TypeHint,
        actual: TypeHint,
    },
    UnresolvedWasmComponent {
        function: String,
    },
    UnresolvedWorkerName,
    UnresolvedResourceVariable,
}

impl std::error::Error for RibByteCodeGenerationError {}

impl Display for RibByteCodeGenerationError {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        match self {
            RibByteCodeGenerationError::CastError(msg) => write!(f, "cast error: {msg}"),
            RibByteCodeGenerationError::AnalysedTypeConversionError(msg) => {
                write!(f, "{msg}")
            }
            RibByteCodeGenerationError::PatternMatchDesugarError => {
                write!(f, "Pattern match desugar error")
            }
            RibByteCodeGenerationError::RangeSelectionDesugarError(msg) => {
                write!(f, "Range selection desugar error: {msg}")
            }
            RibByteCodeGenerationError::UnexpectedTypeError { expected, actual } => {
                write!(
                    f,
                    "Expected type: {}, but got: {}",
                    expected.get_type_kind(),
                    actual.get_type_kind()
                )
            }
            RibByteCodeGenerationError::UnresolvedWasmComponent { function } => {
                write!(f, "Unresolved wasm component for function: {function}")
            }
            RibByteCodeGenerationError::UnresolvedWorkerName => {
                write!(f, "inline invocation of functions on an instance expression is currently not supported")
            }
            _ => {
                write!(f, "inline invocation of methods on resource constructor instance is currently not supported")
            }
        }
    }
}

impl RibByteCode {
    pub fn len(&self) -> usize {
        self.instructions.len()
    }

    pub fn is_empty(&self) -> bool {
        self.instructions.is_empty()
    }

    // Convert expression to bytecode instructions
    pub fn from_expr(
        inferred_expr: &InferredExpr,
    ) -> Result<RibByteCode, RibByteCodeGenerationError> {
        let expr: &Expr = inferred_expr.get_expr();
        let mut instructions = Vec::new();
        let mut stack: Vec<ExprState> = Vec::new();
        let mut instruction_id = InstructionId::init();
        stack.push(ExprState::from_expr(expr));

        while let Some(remaining) = stack.pop() {
            match remaining {
                ExprState::Expr(expr) => {
                    internal::process_expr(
                        &expr,
                        &mut stack,
                        &mut instructions,
                        &mut instruction_id,
                    )?;
                }

                ExprState::Instruction(instruction) => {
                    instructions.push(instruction);
                }
            }
        }

        // Use VecDeque to avoid reversal, but ok as well since this is compilation
        Ok(RibByteCode {
            instructions: instructions.into_iter().rev().collect(),
        })
    }
}
mod internal {
    use crate::compiler::desugar::{desugar_pattern_match, desugar_range_selection};
    use crate::wit_type::{TypeFlags, WitType};
    use crate::{
        DynamicParsedFunctionReference, Expr, FunctionReferenceType, InferredType,
        InstanceIdentifier, InstanceVariable, InstructionId, Range, RibByteCodeGenerationError,
        RibIR, TypeInternal, VariableId, WitTypeWithUnit,
    };
    use std::collections::HashSet;

    use crate::call_type::{CallType, InstanceCreationType};
    use crate::type_inference::{GetTypeHint, TypeHint};
    use crate::wit_type::bool;
    use crate::{IntoValueAndType, Value, ValueAndType};
    use std::ops::Deref;

    pub(crate) fn process_expr(
        expr: &Expr,
        stack: &mut Vec<ExprState>,
        instructions: &mut Vec<RibIR>,
        instruction_id: &mut InstructionId,
    ) -> Result<(), RibByteCodeGenerationError> {
        match expr {
            Expr::Unwrap { expr, .. } => {
                stack.push(ExprState::from_expr(expr.deref()));
                instructions.push(RibIR::Deconstruct);
            }

            Expr::GenerateWorkerName { variable_id, .. } => {
                instructions.push(RibIR::GenerateWorkerName(variable_id.clone()));
            }

            Expr::Length { expr, .. } => {
                stack.push(ExprState::from_expr(expr.deref()));
                instructions.push(RibIR::Length);
            }

            Expr::Throw { message, .. } => {
                instructions.push(RibIR::Throw(message.to_string()));
            }
            Expr::Identifier { variable_id, .. } => {
                instructions.push(RibIR::LoadVar(variable_id.clone()));
            }
            Expr::Literal { value, .. } => {
                let value_and_type = value.clone().into_value_and_type();
                instructions.push(RibIR::PushLit(value_and_type));
            }
            Expr::Number {
                number,
                inferred_type,
                ..
            } => {
                let analysed_type = convert_to_analysed_type(expr, inferred_type)?;

                let value_and_type =
                    number
                        .to_val(&analysed_type)
                        .ok_or(RibByteCodeGenerationError::CastError(format!(
                            "internal error: cannot convert {} to a value of type {}",
                            number.value,
                            analysed_type.get_type_hint()
                        )))?;

                instructions.push(RibIR::PushLit(value_and_type));
            }
            Expr::EqualTo { lhs, rhs, .. } => {
                stack.push(ExprState::from_expr(rhs.deref()));
                stack.push(ExprState::from_expr(lhs.deref()));
                instructions.push(RibIR::EqualTo);
            }
            Expr::GreaterThan { lhs, rhs, .. } => {
                stack.push(ExprState::from_expr(rhs.deref()));
                stack.push(ExprState::from_expr(lhs.deref()));
                instructions.push(RibIR::GreaterThan);
            }
            Expr::LessThan { lhs, rhs, .. } => {
                stack.push(ExprState::from_expr(rhs.deref()));
                stack.push(ExprState::from_expr(lhs.deref()));
                instructions.push(RibIR::LessThan);
            }
            Expr::GreaterThanOrEqualTo { lhs, rhs, .. } => {
                stack.push(ExprState::from_expr(rhs.deref()));
                stack.push(ExprState::from_expr(lhs.deref()));
                instructions.push(RibIR::GreaterThanOrEqualTo);
            }
            Expr::LessThanOrEqualTo { lhs, rhs, .. } => {
                stack.push(ExprState::from_expr(rhs.deref()));
                stack.push(ExprState::from_expr(lhs.deref()));
                instructions.push(RibIR::LessThanOrEqualTo);
            }
            Expr::Plus {
                lhs,
                rhs,
                inferred_type,
                ..
            } => {
                let analysed_type = convert_to_analysed_type(expr, inferred_type)?;
                stack.push(ExprState::from_expr(rhs.deref()));
                stack.push(ExprState::from_expr(lhs.deref()));
                instructions.push(RibIR::Plus(analysed_type));
            }
            Expr::Minus {
                lhs,
                rhs,
                inferred_type,
                ..
            } => {
                let analysed_type = convert_to_analysed_type(expr, inferred_type)?;

                stack.push(ExprState::from_expr(rhs.deref()));
                stack.push(ExprState::from_expr(lhs.deref()));
                instructions.push(RibIR::Minus(analysed_type));
            }
            Expr::Divide {
                lhs,
                rhs,
                inferred_type,
                ..
            } => {
                let analysed_type = convert_to_analysed_type(expr, inferred_type)?;

                stack.push(ExprState::from_expr(rhs.deref()));
                stack.push(ExprState::from_expr(lhs.deref()));
                instructions.push(RibIR::Divide(analysed_type));
            }
            Expr::Multiply {
                lhs,
                rhs,
                inferred_type,
                ..
            } => {
                let analysed_type = convert_to_analysed_type(expr, inferred_type)?;

                stack.push(ExprState::from_expr(rhs.deref()));
                stack.push(ExprState::from_expr(lhs.deref()));
                instructions.push(RibIR::Multiply(analysed_type));
            }
            Expr::And { lhs, rhs, .. } => {
                // This optimization isn't optional, it's required for the correct functioning of the interpreter
                let optimised_expr = Expr::cond(
                    Expr::equal_to(lhs.deref().clone(), Expr::boolean(true)),
                    Expr::equal_to(rhs.deref().clone(), Expr::boolean(true)),
                    Expr::boolean(false),
                );

                stack.push(ExprState::from_expr(&optimised_expr));
            }

            Expr::Or { lhs, rhs, .. } => {
                let optimised_expr = Expr::cond(
                    Expr::equal_to(lhs.deref().clone(), Expr::boolean(true)),
                    Expr::boolean(true),
                    Expr::equal_to(rhs.deref().clone(), Expr::boolean(true)),
                );

                stack.push(ExprState::from_expr(&optimised_expr));
            }

            Expr::Record {
                exprs,
                inferred_type,
                ..
            } => {
                // Push field instructions in reverse order
                for (field_name, field_expr) in exprs.iter().rev() {
                    stack.push(ExprState::from_expr(field_expr.as_ref()));
                    instructions.push(RibIR::UpdateRecord(field_name.clone()));
                }
                // Push record creation instruction
                let analysed_type = convert_to_analysed_type(expr, inferred_type);
                instructions.push(RibIR::CreateAndPushRecord(analysed_type?));
            }
            Expr::Sequence {
                exprs,
                inferred_type,
                ..
            } => {
                // Push all expressions in reverse order
                for expr in exprs.iter().rev() {
                    stack.push(ExprState::from_expr(expr));
                }

                let analysed_type = convert_to_analysed_type(expr, inferred_type)?;
                instructions.push(RibIR::PushList(analysed_type, exprs.len()));
            }
            Expr::ExprBlock { exprs, .. } => {
                // Push all expressions in reverse order
                for expr in exprs.iter() {
                    stack.push(ExprState::from_expr(expr));
                }
            }
            Expr::Let {
                variable_id, expr, ..
            } => {
                stack.push(ExprState::from_expr(expr.deref()));
                instructions.push(RibIR::AssignVar(variable_id.clone()));
            }
            Expr::PatternMatch {
                predicate,
                match_arms,
                inferred_type,
                ..
            } => {
                let desugared_pattern_match =
                    desugar_pattern_match(predicate.deref(), match_arms, inferred_type.clone())
                        .ok_or(RibByteCodeGenerationError::PatternMatchDesugarError)?;

                stack.push(ExprState::from_expr(&desugared_pattern_match));
            }
            Expr::Cond { cond, lhs, rhs, .. } => {
                handle_if_condition(
                    instruction_id,
                    cond.deref(),
                    lhs.deref(),
                    rhs.deref(),
                    stack,
                );
            }

            Expr::SelectField { expr, field, .. } => {
                stack.push(ExprState::from_expr(expr.deref()));
                instructions.push(RibIR::SelectField(field.clone()));
            }

            Expr::SelectIndex { expr, index, .. } => match index.inferred_type().internal_type() {
                TypeInternal::Range { .. } => {
                    let list_comprehension =
                        desugar_range_selection(expr, index).map_err(|err| {
                            RibByteCodeGenerationError::RangeSelectionDesugarError(format!(
                                "Failed to desugar range selection: {err}"
                            ))
                        })?;
                    stack.push(ExprState::from_expr(&list_comprehension));
                }
                _ => {
                    stack.push(ExprState::from_expr(index.deref()));
                    stack.push(ExprState::from_expr(expr.deref()));
                    instructions.push(RibIR::SelectIndexV1);
                }
            },

            Expr::Option {
                expr: Some(inner_expr),
                inferred_type,
                ..
            } => {
                stack.push(ExprState::from_expr(inner_expr.deref()));
                instructions.push(RibIR::PushSome(convert_to_analysed_type(
                    expr,
                    inferred_type,
                )?));
            }

            Expr::Option { inferred_type, .. } => {
                let optional = convert_to_analysed_type(expr, inferred_type);
                instructions.push(RibIR::PushNone(optional.ok()));
            }

            Expr::Result {
                expr: Ok(inner_expr),
                inferred_type,
                ..
            } => {
                stack.push(ExprState::from_expr(inner_expr.deref()));
                instructions.push(RibIR::PushOkResult(convert_to_analysed_type(
                    expr,
                    inferred_type,
                )?));
            }

            Expr::Result {
                expr: Err(inner_expr),
                inferred_type,
                ..
            } => {
                stack.push(ExprState::from_expr(inner_expr.deref()));
                instructions.push(RibIR::PushErrResult(convert_to_analysed_type(
                    expr,
                    inferred_type,
                )?));
            }

            Expr::Call {
                call_type,
                args,
                inferred_type,
                ..
            } => {
                // If the call type is an instance creation (worker creation),
                // this will push worker name expression.
                match call_type {
                    CallType::Function {
                        function_name,
                        instance_identifier: module,
                        component_info,
                    } => {
                        for expr in args.iter().rev() {
                            stack.push(ExprState::from_expr(expr));
                        }

                        let function_result_type = if inferred_type.is_unit() {
                            WitTypeWithUnit::Unit
                        } else {
                            WitTypeWithUnit::Type(convert_to_analysed_type(expr, inferred_type)?)
                        };

                        let module = module
                            .as_ref()
                            .expect("Module should be present for function calls");

                        let instance_variable = match module.as_ref() {
                            InstanceIdentifier::WitResource { variable_id, .. } => {
                                let variable_id = variable_id.clone().unwrap_or_else(|| {
                                    VariableId::global("___STATIC_WIT_RESOURCE".to_string())
                                });
                                InstanceVariable::WitResource(variable_id)
                            }
                            InstanceIdentifier::WitWorker { variable_id, .. } => {
                                let variable_id = variable_id
                                    .clone()
                                    .ok_or(RibByteCodeGenerationError::UnresolvedWorkerName)?;

                                InstanceVariable::WitWorker(variable_id)
                            }
                        };

                        let component_info = component_info.as_ref().ok_or(
                            RibByteCodeGenerationError::UnresolvedWasmComponent {
                                function: function_name.to_string(),
                            },
                        )?;

                        instructions.push(RibIR::InvokeFunction(
                            component_info.clone(),
                            instance_variable,
                            args.len(),
                            function_result_type,
                        ));

                        let site = function_name.site.clone();

                        // Resolve the function name and update stack
                        match &function_name.function {
                            DynamicParsedFunctionReference::Function { function } => instructions
                                .push(RibIR::CreateFunctionName(
                                    site,
                                    FunctionReferenceType::Function {
                                        function: function.clone(),
                                    },
                                )),

                            DynamicParsedFunctionReference::RawResourceConstructor { resource } => {
                                instructions.push(RibIR::CreateFunctionName(
                                    site,
                                    FunctionReferenceType::RawResourceConstructor {
                                        resource: resource.clone(),
                                    },
                                ))
                            }
                            DynamicParsedFunctionReference::RawResourceDrop { resource } => {
                                instructions.push(RibIR::CreateFunctionName(
                                    site,
                                    FunctionReferenceType::RawResourceDrop {
                                        resource: resource.clone(),
                                    },
                                ))
                            }
                            DynamicParsedFunctionReference::RawResourceMethod {
                                resource,
                                method,
                            } => instructions.push(RibIR::CreateFunctionName(
                                site,
                                FunctionReferenceType::RawResourceMethod {
                                    resource: resource.clone(),
                                    method: method.clone(),
                                },
                            )),
                            DynamicParsedFunctionReference::RawResourceStaticMethod {
                                resource,
                                method,
                            } => instructions.push(RibIR::CreateFunctionName(
                                site,
                                FunctionReferenceType::RawResourceStaticMethod {
                                    resource: resource.clone(),
                                    method: method.clone(),
                                },
                            )),
                        }
                    }

                    // if there are no arguments to instance that would typically mean
                    // it's an ephemeral worker or a resource with no arguments
                    // This would imply there is nothing in the stack of instructions related
                    // to these cases. So to make sure expressions such as the following work,
                    // we need to push a place holder in the stack that does nothing
                    CallType::InstanceCreation(instance_creation_type) => {
                        match instance_creation_type {
                            InstanceCreationType::WitWorker { worker_name, .. } => {
                                if let Some(worker_name) = worker_name {
                                    stack.push(ExprState::from_expr(worker_name));
                                } else {
                                    for expr in args.iter().rev() {
                                        stack.push(ExprState::from_expr(expr));
                                    }
                                }
                            }

                            InstanceCreationType::WitResource {
                                module,
                                resource_name,
                                component_info,
                            } => {
                                for expr in args.iter().rev() {
                                    stack.push(ExprState::from_expr(expr));
                                }

                                let module = module
                                    .as_ref()
                                    .expect("Module should be present for resource calls");

                                let instance_variable = match module {
                                    InstanceIdentifier::WitResource { variable_id, .. } => {
                                        let variable_id = variable_id.as_ref().ok_or({
                                            RibByteCodeGenerationError::UnresolvedResourceVariable
                                        })?;

                                        InstanceVariable::WitResource(variable_id.clone())
                                    }
                                    InstanceIdentifier::WitWorker { variable_id, .. } => {
                                        let variable_id = variable_id.as_ref().ok_or({
                                            RibByteCodeGenerationError::UnresolvedWorkerName
                                        })?;

                                        InstanceVariable::WitWorker(variable_id.clone())
                                    }
                                };

                                let site = resource_name.parsed_function_site();

                                let component_info = component_info.as_ref().ok_or(
                                    RibByteCodeGenerationError::UnresolvedWasmComponent {
                                        function: resource_name.resource_name.clone(),
                                    },
                                )?;

                                let function_result_type = if inferred_type.is_unit() {
                                    WitTypeWithUnit::Unit
                                } else {
                                    WitTypeWithUnit::Type(convert_to_analysed_type(
                                        expr,
                                        inferred_type,
                                    )?)
                                };

                                instructions.push(RibIR::InvokeFunction(
                                    component_info.clone(),
                                    instance_variable,
                                    args.len(),
                                    function_result_type,
                                ));

                                instructions.push(RibIR::CreateFunctionName(
                                    site,
                                    FunctionReferenceType::RawResourceConstructor {
                                        resource: resource_name.resource_name.clone(),
                                    },
                                ));
                            }
                        }
                    }

                    CallType::VariantConstructor(variant_name) => {
                        for expr in args.iter().rev() {
                            stack.push(ExprState::from_expr(expr));
                        }

                        instructions.push(RibIR::PushVariant(
                            variant_name.clone(),
                            convert_to_analysed_type(expr, inferred_type)?,
                        ));
                    }
                    CallType::EnumConstructor(enum_name) => {
                        for expr in args.iter().rev() {
                            stack.push(ExprState::from_expr(expr));
                        }

                        instructions.push(RibIR::PushEnum(
                            enum_name.clone(),
                            convert_to_analysed_type(expr, inferred_type)?,
                        ));
                    }
                }
            }

            Expr::Flags {
                flags,
                inferred_type,
                ..
            } => match inferred_type.internal_type() {
                TypeInternal::Flags(all_flags) => {
                    let mut bitmap = Vec::new();
                    let flag_values_set: HashSet<&String> = HashSet::from_iter(flags.iter());
                    for flag in all_flags.iter() {
                        bitmap.push(flag_values_set.contains(flag));
                    }
                    instructions.push(RibIR::PushFlag(ValueAndType {
                        value: Value::Flags(bitmap),
                        typ: WitType::Flags(TypeFlags {
                            names: all_flags.iter().map(|n| n.to_string()).collect(),
                            owner: None,
                            name: None,
                        }),
                    }));
                }
                _ => {
                    return Err(RibByteCodeGenerationError::UnexpectedTypeError {
                        expected: TypeHint::Flag(Some(flags.clone())),
                        actual: inferred_type.get_type_hint(),
                    });
                }
            },
            Expr::Boolean { value, .. } => {
                instructions.push(RibIR::PushLit(value.into_value_and_type()));
            }
            Expr::GetTag { expr, .. } => {
                stack.push(ExprState::from_expr(expr.deref()));
                stack.push(ExprState::from_ir(RibIR::GetTag));
            }

            Expr::Concat { exprs, .. } => {
                for expr in exprs.iter().rev() {
                    stack.push(ExprState::from_expr(expr));
                }

                instructions.push(RibIR::Concat(exprs.len()));
            }

            Expr::Not { expr, .. } => {
                stack.push(ExprState::from_expr(expr.deref()));
                instructions.push(RibIR::Negate);
            }

            Expr::Tuple {
                exprs,
                inferred_type,
                ..
            } => {
                for expr in exprs.iter().rev() {
                    stack.push(ExprState::from_expr(expr));
                }
                let analysed_type = convert_to_analysed_type(expr, inferred_type)?;
                instructions.push(RibIR::PushTuple(analysed_type, exprs.len()));
            }

            Expr::ListComprehension {
                iterated_variable,
                iterable_expr,
                yield_expr,
                inferred_type,
                ..
            } => {
                let analysed_type = convert_to_analysed_type(expr, inferred_type)?;
                handle_list_comprehension(
                    instruction_id,
                    stack,
                    iterable_expr,
                    yield_expr,
                    iterated_variable,
                    &analysed_type,
                )
            }

            range_expr @ Expr::Range {
                range,
                inferred_type,
                ..
            } => match inferred_type.internal_type() {
                TypeInternal::Range { .. } => {
                    let analysed_type = convert_to_analysed_type(range_expr, inferred_type)?;

                    handle_range(range, stack, analysed_type, instructions);
                }

                _ => {
                    return Err(RibByteCodeGenerationError::UnexpectedTypeError {
                        expected: TypeHint::Range,
                        actual: inferred_type.get_type_hint(),
                    });
                }
            },

            // Invoke is always handled by the CallType::Function branch
            Expr::InvokeMethodLazy { .. } => {}

            Expr::ListReduce {
                reduce_variable,
                iterated_variable,
                iterable_expr,
                init_value_expr,
                yield_expr,
                ..
            } => handle_list_reduce(
                instruction_id,
                stack,
                reduce_variable,
                iterated_variable,
                iterable_expr,
                init_value_expr,
                yield_expr,
            ),
        }

        Ok(())
    }

    pub(crate) fn convert_to_analysed_type(
        expr: &Expr,
        inferred_type: &InferredType,
    ) -> Result<WitType, RibByteCodeGenerationError> {
        WitType::try_from(inferred_type).map_err(|error| {
            RibByteCodeGenerationError::AnalysedTypeConversionError(format!(
                "Invalid Rib {}. Error converting {} to WitType: {}",
                expr,
                inferred_type.get_type_hint(),
                error
            ))
        })
    }

    // We create a temporary stack of expressions that we pop one by one,
    // while injecting some pre-defined IRs such as Jump in certain cases
    // A stack is required on one side to maintain the order of expressions
    // As soon a `Expr` becomes `Instruction` the instruction stack will be in order.
    pub(crate) enum ExprState {
        Expr(Expr),
        Instruction(RibIR),
    }

    impl ExprState {
        pub(crate) fn from_expr(expr: &Expr) -> Self {
            ExprState::Expr(expr.clone())
        }

        pub(crate) fn from_ir(ir: RibIR) -> Self {
            ExprState::Instruction(ir)
        }
    }

    fn handle_range(
        range: &Range,
        stack: &mut Vec<ExprState>,
        analysed_type: WitType,
        instructions: &mut Vec<RibIR>,
    ) {
        let from = range.from();
        let to = range.to();
        let inclusive = range.inclusive();

        if let Some(from) = from {
            stack.push(ExprState::from_expr(from));
            instructions.push(RibIR::UpdateRecord("from".to_string()));
        }

        if let Some(to) = to {
            stack.push(ExprState::from_expr(to));
            instructions.push(RibIR::UpdateRecord("to".to_string()));
        }

        stack.push(ExprState::from_ir(RibIR::PushLit(ValueAndType::new(
            Value::Bool(inclusive),
            bool(),
        ))));

        instructions.push(RibIR::UpdateRecord("inclusive".to_string()));

        instructions.push(RibIR::CreateAndPushRecord(analysed_type));
    }

    fn handle_list_comprehension(
        instruction_id: &mut InstructionId,
        stack: &mut Vec<ExprState>,
        iterable_expr: &Expr,
        yield_expr: &Expr,
        variable_id: &VariableId,
        sink_type: &WitType,
    ) {
        stack.push(ExprState::from_expr(iterable_expr));

        stack.push(ExprState::from_ir(RibIR::ToIterator));

        stack.push(ExprState::from_ir(RibIR::CreateSink(sink_type.clone())));

        let loop_start_label = instruction_id.increment_mut();

        stack.push(ExprState::from_ir(RibIR::Label(loop_start_label.clone())));

        let exit_label = instruction_id.increment_mut();

        stack.push(ExprState::from_ir(RibIR::IsEmpty));

        stack.push(ExprState::from_ir(RibIR::JumpIfFalse(exit_label.clone())));

        stack.push(ExprState::from_ir(RibIR::AdvanceIterator));

        stack.push(ExprState::from_ir(RibIR::AssignVar(variable_id.clone())));

        stack.push(ExprState::from_expr(yield_expr));

        stack.push(ExprState::from_ir(RibIR::PushToSink));

        stack.push(ExprState::from_ir(RibIR::Jump(loop_start_label)));

        stack.push(ExprState::from_ir(RibIR::Label(exit_label)));

        stack.push(ExprState::from_ir(RibIR::SinkToList))
    }

    fn handle_list_reduce(
        instruction_id: &mut InstructionId,
        stack: &mut Vec<ExprState>,
        reduce_variable: &VariableId,
        iterated_variable: &VariableId,
        iterable_expr: &Expr,
        initial_value_expr: &Expr,
        yield_expr: &Expr,
    ) {
        stack.push(ExprState::from_expr(iterable_expr));

        stack.push(ExprState::from_expr(initial_value_expr));

        stack.push(ExprState::from_ir(RibIR::AssignVar(
            reduce_variable.clone(),
        )));

        stack.push(ExprState::from_ir(RibIR::ToIterator));

        let loop_start_label = instruction_id.increment_mut();

        stack.push(ExprState::from_ir(RibIR::Label(loop_start_label.clone())));

        let exit_label = instruction_id.increment_mut();

        stack.push(ExprState::from_ir(RibIR::IsEmpty));

        stack.push(ExprState::from_ir(RibIR::JumpIfFalse(exit_label.clone())));

        stack.push(ExprState::from_ir(RibIR::AdvanceIterator));

        stack.push(ExprState::from_ir(RibIR::AssignVar(
            iterated_variable.clone(),
        )));

        stack.push(ExprState::from_expr(yield_expr));

        stack.push(ExprState::from_ir(RibIR::AssignVar(
            reduce_variable.clone(),
        )));

        stack.push(ExprState::from_ir(RibIR::Jump(loop_start_label)));

        stack.push(ExprState::from_ir(RibIR::Label(exit_label)));

        stack.push(ExprState::from_ir(RibIR::LoadVar(reduce_variable.clone())))
    }

    fn handle_if_condition(
        instruction_id: &mut InstructionId,
        if_expr: &Expr,
        then_expr: &Expr,
        else_expr: &Expr,
        stack: &mut Vec<ExprState>,
    ) {
        instruction_id.increment_mut();
        let else_beginning_id = instruction_id.clone();
        instruction_id.increment_mut();
        let else_ending_id = instruction_id.clone();

        stack.push(ExprState::from_expr(if_expr));

        stack.push(ExprState::from_ir(RibIR::JumpIfFalse(
            else_beginning_id.clone(),
        )));

        stack.push(ExprState::from_expr(then_expr));

        stack.push(ExprState::from_ir(RibIR::Jump(else_ending_id.clone())));

        stack.push(ExprState::from_ir(RibIR::Label(else_beginning_id.clone())));

        stack.push(ExprState::from_expr(else_expr));

        stack.push(ExprState::from_ir(RibIR::Label(else_ending_id.clone())));
    }
}

#[cfg(test)]
mod compiler_tests {
    use bigdecimal::BigDecimal;
    use test_r::test;

    use super::*;
    use crate::wit_type::builders as wit_type;
    use crate::wit_type::{field, list, record, s32, str};
    use crate::{ArmPattern, InferredType, MatchArm, RibCompiler, VariableId};
    use crate::{IntoValueAndType, Value, ValueAndType};

    #[test]
    fn test_instructions_for_literal() {
        let literal = Expr::literal("hello");

        let compiler = RibCompiler::default();

        let compiler_output = compiler.compile(literal).unwrap();

        let instruction_set = vec![RibIR::PushLit("hello".into_value_and_type())];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(compiler_output.byte_code, expected_instructions);
    }

    #[test]
    fn test_instructions_for_identifier() {
        let inferred_input_type = InferredType::string();

        let variable_id = VariableId::local("request", 0);

        let expr = Expr::identifier_with_variable_id(variable_id.clone(), None)
            .with_inferred_type(inferred_input_type);

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let instruction_set = vec![RibIR::LoadVar(variable_id)];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_assign_variable() {
        let literal = Expr::literal("hello");

        let variable_id = VariableId::local("request", 0);

        let expr = Expr::let_binding_with_variable_id(variable_id.clone(), literal, None);

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let instruction_set = vec![
            RibIR::PushLit("hello".into_value_and_type()),
            RibIR::AssignVar(variable_id),
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_equal_to() {
        let number_f32 = Expr::number_inferred(BigDecimal::from(1), None, InferredType::f32());

        let number_u32 = Expr::number_inferred(BigDecimal::from(1), None, InferredType::u32());

        let expr = Expr::equal_to(number_f32, number_u32);

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let value_and_type1 = 1.0f32.into_value_and_type();

        let value_and_type2 = 1u32.into_value_and_type();

        let instruction_set = vec![
            RibIR::PushLit(value_and_type2),
            RibIR::PushLit(value_and_type1),
            RibIR::EqualTo,
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_greater_than() {
        let number_f32 = Expr::number_inferred(BigDecimal::from(1), None, InferredType::f32());

        let number_u32 = Expr::number_inferred(BigDecimal::from(2), None, InferredType::u32());

        let expr = Expr::greater_than(number_f32, number_u32);

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let value_and_type1 = 1.0f32.into_value_and_type();

        let value_and_type2 = 2u32.into_value_and_type();

        let instruction_set = vec![
            RibIR::PushLit(value_and_type2),
            RibIR::PushLit(value_and_type1),
            RibIR::GreaterThan,
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_less_than() {
        let number_f32 = Expr::number_inferred(BigDecimal::from(1), None, InferredType::f32());

        let number_u32 = Expr::number_inferred(BigDecimal::from(1), None, InferredType::u32());

        let expr = Expr::less_than(number_f32, number_u32);

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let value_and_type1 = 1.0f32.into_value_and_type();

        let value_and_type2 = 1u32.into_value_and_type();

        let instruction_set = vec![
            RibIR::PushLit(value_and_type2),
            RibIR::PushLit(value_and_type1),
            RibIR::LessThan,
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_greater_than_or_equal_to() {
        let number_f32 = Expr::number_inferred(BigDecimal::from(1), None, InferredType::f32());

        let number_u32 = Expr::number_inferred(BigDecimal::from(1), None, InferredType::u32());

        let expr = Expr::greater_than_or_equal_to(number_f32, number_u32);

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let value_and_type1 = 1.0f32.into_value_and_type();

        let value_and_type2 = 1u32.into_value_and_type();

        let instruction_set = vec![
            RibIR::PushLit(value_and_type2),
            RibIR::PushLit(value_and_type1),
            RibIR::GreaterThanOrEqualTo,
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_less_than_or_equal_to() {
        let number_f32 = Expr::number_inferred(BigDecimal::from(1), None, InferredType::f32());

        let number_u32 = Expr::number_inferred(BigDecimal::from(1), None, InferredType::u32());

        let expr = Expr::less_than_or_equal_to(number_f32, number_u32);

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let value_and_type1 = 1.0f32.into_value_and_type();

        let value_and_type2 = 1u32.into_value_and_type();

        let instruction_set = vec![
            RibIR::PushLit(value_and_type2),
            RibIR::PushLit(value_and_type1),
            RibIR::LessThanOrEqualTo,
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_for_record() {
        let expr = Expr::record(vec![
            ("foo_key".to_string(), Expr::literal("foo_value")),
            ("bar_key".to_string(), Expr::literal("bar_value")),
        ])
        .with_inferred_type(InferredType::record(vec![
            (String::from("foo_key"), InferredType::string()),
            (String::from("bar_key"), InferredType::string()),
        ]));

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let bar_value = "bar_value".into_value_and_type();

        let foo_value = "foo_value".into_value_and_type();

        let instruction_set = vec![
            RibIR::PushLit(bar_value),
            RibIR::PushLit(foo_value),
            RibIR::CreateAndPushRecord(record(vec![
                field("foo_key", str()),
                field("bar_key", str()),
            ])),
            RibIR::UpdateRecord("foo_key".to_string()),
            RibIR::UpdateRecord("bar_key".to_string()),
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_for_multiple() {
        let expr = Expr::expr_block(vec![Expr::literal("foo"), Expr::literal("bar")]);

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let instruction_set = vec![
            RibIR::PushLit("foo".into_value_and_type()),
            RibIR::PushLit("bar".into_value_and_type()),
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_if_conditional() {
        let if_expr = Expr::literal("pred").with_inferred_type(InferredType::bool());

        let then_expr = Expr::literal("then");

        let else_expr = Expr::literal("else");

        let expr =
            Expr::cond(if_expr, then_expr, else_expr).with_inferred_type(InferredType::string());

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let instruction_set = vec![
            RibIR::PushLit("pred".into_value_and_type()),
            RibIR::JumpIfFalse(InstructionId { index: 1 }), // jumps to the next label having Id 1 (which is else block)
            RibIR::PushLit("then".into_value_and_type()),
            RibIR::Jump(InstructionId { index: 2 }), // Once if is executed then jump to the end of the else block with id 2
            RibIR::Label(InstructionId { index: 1 }),
            RibIR::PushLit("else".into_value_and_type()),
            RibIR::Label(InstructionId { index: 2 }),
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_for_nested_if_else() {
        let if_expr = Expr::literal("if-pred1").with_inferred_type(InferredType::bool());

        let then_expr = Expr::literal("then1").with_inferred_type(InferredType::string());

        let else_expr = Expr::cond(
            Expr::literal("else-pred2").with_inferred_type(InferredType::bool()),
            Expr::literal("else-then2"),
            Expr::literal("else-else2"),
        )
        .with_inferred_type(InferredType::string());

        let expr =
            Expr::cond(if_expr, then_expr, else_expr).with_inferred_type(InferredType::string());

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let instruction_set = vec![
            // if case
            RibIR::PushLit("if-pred1".into_value_and_type()),
            RibIR::JumpIfFalse(InstructionId { index: 1 }), // jumps to the next label having Id 1 (which is else block)
            RibIR::PushLit("then1".into_value_and_type()),
            RibIR::Jump(InstructionId { index: 2 }), // Once if is executed then jump to the end of the else block with id 3
            RibIR::Label(InstructionId { index: 1 }),
            RibIR::PushLit("else-pred2".into_value_and_type()),
            RibIR::JumpIfFalse(InstructionId { index: 3 }), // jumps to the next label having Id 2 (which is else block)
            RibIR::PushLit("else-then2".into_value_and_type()),
            RibIR::Jump(InstructionId { index: 4 }), // Once if is executed then jump to the end of the else block with id 3
            RibIR::Label(InstructionId { index: 3 }),
            RibIR::PushLit("else-else2".into_value_and_type()),
            RibIR::Label(InstructionId { index: 4 }),
            RibIR::Label(InstructionId { index: 2 }),
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_for_select_field() {
        let record = Expr::record(vec![
            ("foo_key".to_string(), Expr::literal("foo_value")),
            ("bar_key".to_string(), Expr::literal("bar_value")),
        ])
        .with_inferred_type(InferredType::record(vec![
            (String::from("foo_key"), InferredType::string()),
            (String::from("bar_key"), InferredType::string()),
        ]));

        let expr =
            Expr::select_field(record, "bar_key", None).with_inferred_type(InferredType::string());

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let bar_value = "bar_value".into_value_and_type();

        let foo_value = "foo_value".into_value_and_type();

        let instruction_set = vec![
            RibIR::PushLit(bar_value),
            RibIR::PushLit(foo_value),
            RibIR::CreateAndPushRecord(wit_type::record(vec![
                field("bar_key", str()),
                field("foo_key", str()),
            ])),
            RibIR::UpdateRecord("foo_key".to_string()), // next pop is foo_value
            RibIR::UpdateRecord("bar_key".to_string()), // last pop is bar_value
            RibIR::SelectField("bar_key".to_string()),
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_for_select_index() {
        let sequence = Expr::sequence(vec![Expr::literal("foo"), Expr::literal("bar")], None)
            .with_inferred_type(InferredType::list(InferredType::string()));

        let expr = Expr::select_index(sequence, Expr::number(BigDecimal::from(1)))
            .with_inferred_type(InferredType::string());

        let compiler = RibCompiler::default();

        let inferred_expr = compiler.infer_types(expr).unwrap();

        let instructions = RibByteCode::from_expr(&inferred_expr).unwrap();

        let instruction_set = vec![
            RibIR::PushLit(ValueAndType::new(Value::S32(1), s32())),
            RibIR::PushLit("bar".into_value_and_type()),
            RibIR::PushLit("foo".into_value_and_type()),
            RibIR::PushList(list(str()), 2),
            RibIR::SelectIndexV1,
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[test]
    fn test_instructions_for_expr_arm_pattern_match() {
        let expr = Expr::pattern_match(
            Expr::literal("pred"),
            vec![
                MatchArm::new(
                    ArmPattern::Literal(Box::new(Expr::literal("arm1_pattern_expr"))),
                    Expr::literal("arm1_resolution_expr"),
                ),
                MatchArm::new(
                    ArmPattern::Literal(Box::new(Expr::literal("arm2_pattern_expr"))),
                    Expr::literal("arm2_resolution_expr"),
                ),
                MatchArm::new(
                    ArmPattern::Literal(Box::new(Expr::literal("arm3_pattern_expr"))),
                    Expr::literal("arm3_resolution_expr"),
                ),
            ],
        )
        .with_inferred_type(InferredType::string());

        let rib_compiler = RibCompiler::default();

        let instructions = rib_compiler.compile(expr).unwrap().byte_code;

        // instructions will correspond to an if-else statement
        let instruction_set = vec![
            RibIR::PushLit("arm1_pattern_expr".into_value_and_type()),
            RibIR::PushLit("pred".into_value_and_type()),
            RibIR::EqualTo,
            RibIR::JumpIfFalse(InstructionId { index: 1 }),
            RibIR::PushLit("arm1_resolution_expr".into_value_and_type()),
            RibIR::Jump(InstructionId { index: 2 }),
            RibIR::Label(InstructionId { index: 1 }),
            RibIR::PushLit("arm2_pattern_expr".into_value_and_type()),
            RibIR::PushLit("pred".into_value_and_type()),
            RibIR::EqualTo,
            RibIR::JumpIfFalse(InstructionId { index: 3 }),
            RibIR::PushLit("arm2_resolution_expr".into_value_and_type()),
            RibIR::Jump(InstructionId { index: 4 }),
            RibIR::Label(InstructionId { index: 3 }),
            RibIR::PushLit("arm3_pattern_expr".into_value_and_type()),
            RibIR::PushLit("pred".into_value_and_type()),
            RibIR::EqualTo,
            RibIR::JumpIfFalse(InstructionId { index: 5 }),
            RibIR::PushLit("arm3_resolution_expr".into_value_and_type()),
            RibIR::Jump(InstructionId { index: 6 }),
            RibIR::Label(InstructionId { index: 5 }),
            RibIR::Throw("No match found".to_string()),
            RibIR::Label(InstructionId { index: 6 }),
            RibIR::Label(InstructionId { index: 4 }),
            RibIR::Label(InstructionId { index: 2 }),
        ];

        let expected_instructions = RibByteCode {
            instructions: instruction_set,
        };

        assert_eq!(instructions, expected_instructions);
    }

    #[cfg(test)]
    mod invalid_function_invoke_tests {
        use test_r::test;

        use crate::compiler::byte_code::compiler_tests::internal;
        use crate::wit_type::str;
        use crate::{Expr, RibCompiler, RibCompilerConfig};

        #[test]
        fn test_unknown_function() {
            let expr = r#"
               foo(request);
               "success"
            "#;

            let expr = Expr::from_text(expr).unwrap();
            let compiler = RibCompiler::default();

            let compiler_error = compiler.compile(expr).unwrap_err().to_string();

            assert_eq!(compiler_error, "error in the following rib found at line 2, column 16\n`foo(request)`\ncause: invalid function call `foo`\nunknown function\n");
        }

        #[test]
        fn test_invalid_arg_size_function() {
            let metadata = internal::get_component_metadata("foo", vec![str()], str());

            let expr = r#"
               let user_id = "user";
               let result = foo(user_id, user_id);
               result
            "#;

            let expr = Expr::from_text(expr).unwrap();

            let compiler_config = RibCompilerConfig::new(metadata, vec![], vec![]);

            let compiler = RibCompiler::new(compiler_config);

            let compiler_error = compiler.compile(expr).unwrap_err().to_string();
            assert_eq!(
                compiler_error,
                "error in the following rib found at line 3, column 29\n`foo(user_id, user_id)`\ncause: invalid argument size for function `foo`. expected 1 arguments, found 2\n"
            );
        }

        #[test]
        fn test_invalid_arg_types_function() {
            let metadata = internal::get_component_metadata("foo", vec![str()], str());

            let expr = r#"
               let result = foo(1u64);
               result
            "#;

            let expr = Expr::from_text(expr).unwrap();

            let compiler_config = RibCompilerConfig::new(metadata, vec![], vec![]);

            let compiler = RibCompiler::new(compiler_config);

            let compiler_error = compiler.compile(expr).unwrap_err().to_string();
            assert_eq!(
                compiler_error,
                "error in the following rib found at line 2, column 33\n`1: u64`\ncause: type mismatch. expected string, found u64\ninvalid argument to the function `foo`\n"
            );
        }

        #[test]
        fn test_invalid_arg_types_variants() {
            let metadata = internal::metadata_with_variants();

            let expr = r#"
               let regiser_user_action = register-user("foo");
               let result = golem:it/api.{foo}(regiser_user_action);
               result
            "#;

            let expr = Expr::from_text(expr).unwrap();

            let compiler_config = RibCompilerConfig::new(metadata, vec![], vec![]);

            let compiler = RibCompiler::new(compiler_config);

            let compiler_error = compiler.compile(expr).unwrap_err().to_string();
            assert_eq!(
                compiler_error,
                "error in the following rib found at line 2, column 56\n`\"foo\"`\ncause: type mismatch. expected u64, found string\ninvalid argument to the function `register-user`\n"
            );
        }
    }

    #[cfg(test)]
    mod global_input_tests {
        use test_r::test;

        use crate::compiler::byte_code::compiler_tests::internal;
        use crate::wit_type::{
            case, field, list, option, r#enum, record, result, str, tuple, u32, u64, unit_case,
            variant,
        };
        use crate::{Expr, RibCompiler, RibCompilerConfig};

        #[test]
        async fn test_str_global_input() {
            let request_value_type = str();

            let output_analysed_type = str();

            let analysed_exports = internal::get_component_metadata(
                "my-worker-function",
                vec![request_value_type.clone()],
                output_analysed_type,
            );

            let expr = r#"
               let x = request;
               let worker = instance();
               worker.my-worker-function(x);
               match x {
                "foo"  => "success",
                 _ => "fallback"
               }
            "#;

            let expr = Expr::from_text(expr).unwrap();
            let compiler =
                RibCompiler::new(RibCompilerConfig::new(analysed_exports, vec![], vec![]));
            let compiled = compiler.compile(expr).unwrap();
            let expected_type_info =
                internal::rib_input_type_info(vec![("request", request_value_type)]);

            assert_eq!(compiled.rib_input_type_info, expected_type_info);
        }

        #[test]
        async fn test_number_global_input() {
            let request_value_type = u32();

            let output_analysed_type = str();

            let analysed_exports = internal::get_component_metadata(
                "my-worker-function",
                vec![request_value_type.clone()],
                output_analysed_type,
            );

            let expr = r#"
               let x = request;
               let worker = instance();
               worker.my-worker-function(x);
               match x {
                1  => "success",
                0 => "failure"
               }
            "#;

            let expr = Expr::from_text(expr).unwrap();
            let compiler =
                RibCompiler::new(RibCompilerConfig::new(analysed_exports, vec![], vec![]));
            let compiled = compiler.compile(expr).unwrap();
            let expected_type_info =
                internal::rib_input_type_info(vec![("request", request_value_type)]);

            assert_eq!(compiled.rib_input_type_info, expected_type_info);
        }

        #[test]
        async fn test_variant_type_info() {
            let request_value_type = variant(vec![
                case("register-user", u64()),
                case("process-user", str()),
                unit_case("validate"),
            ]);

            let output_analysed_type = str();

            let analysed_exports = internal::get_component_metadata(
                "my-worker-function",
                vec![request_value_type.clone()],
                output_analysed_type,
            );

            // x = request, implies we are expecting a global variable
            // called request as the  input to Rib.
            // my-worker-function is a function that takes a Variant as input,
            // implies the type of request is a Variant.
            // This means the rib interpreter env has to have a request variable in it,
            // with a value that should be of the type Variant
            let expr = r#"
               let worker = instance();
               worker.my-worker-function(request);
               match request {
                 process-user(user) => user,
                 _ => "default"
               }
            "#;

            let expr = Expr::from_text(expr).unwrap();
            let compiler =
                RibCompiler::new(RibCompilerConfig::new(analysed_exports, vec![], vec![]));
            let compiled = compiler.compile(expr).unwrap();
            let expected_type_info =
                internal::rib_input_type_info(vec![("request", request_value_type)]);

            assert_eq!(compiled.rib_input_type_info, expected_type_info);
        }

        #[test]
        async fn test_result_type_info() {
            let request_value_type = result(u64(), str());

            let output_analysed_type = str();

            let analysed_exports = internal::get_component_metadata(
                "my-worker-function",
                vec![request_value_type.clone()],
                output_analysed_type,
            );

            // x = request, implies we are expecting a global variable
            // called request as the  input to Rib.
            // my-worker-function is a function that takes a Result as input,
            // implies the type of request is a Result.
            // This means the rib interpreter env has to have a request variable in it,
            // with a value that should be of the type Result
            let expr = r#"
               let worker = instance();
               worker.my-worker-function(request);
               match request {
                 ok(x) => "${x}",
                 err(msg) => msg
               }
            "#;

            let expr = Expr::from_text(expr).unwrap();
            let compiler =
                RibCompiler::new(RibCompilerConfig::new(analysed_exports, vec![], vec![]));
            let compiled = compiler.compile(expr).unwrap();
            let expected_type_info =
                internal::rib_input_type_info(vec![("request", request_value_type)]);

            assert_eq!(compiled.rib_input_type_info, expected_type_info);
        }

        #[test]
        async fn test_option_type_info() {
            let request_value_type = option(str());

            let output_analysed_type = str();

            let analysed_exports = internal::get_component_metadata(
                "my-worker-function",
                vec![request_value_type.clone()],
                output_analysed_type,
            );

            // x = request, implies we are expecting a global variable
            // called request as the input to Rib.
            // my-worker-function is a function that takes a Option as input,
            // implies the type of request is a Result.
            // This means the rib interpreter env has to have a request variable in it,
            // with a value that should be of the type Option
            let expr = r#"
               let worker = instance();
               worker.my-worker-function(request);
               match request {
                 some(x) => x,
                 none => "error"
               }
            "#;

            let expr = Expr::from_text(expr).unwrap();
            let compiler =
                RibCompiler::new(RibCompilerConfig::new(analysed_exports, vec![], vec![]));
            let compiled = compiler.compile(expr).unwrap();
            let expected_type_info =
                internal::rib_input_type_info(vec![("request", request_value_type)]);

            assert_eq!(compiled.rib_input_type_info, expected_type_info);
        }

        #[test]
        async fn test_enum_type_info() {
            let request_value_type = r#enum(&["prod", "dev", "test"]);
            let output_analysed_type = str();

            let analysed_exports = internal::get_component_metadata(
                "my-worker-function",
                vec![request_value_type.clone()],
                output_analysed_type,
            );

            // x = request, implies we are expecting a global variable
            // called request as the input to Rib.
            // my-worker-function is a function that takes a Option as input,
            // implies the type of request is a Result.
            // This means the rib interpreter env has to have a request variable in it,
            // with a value that should be of the type Option
            let expr = r#"
               let worker = instance();
               worker.my-worker-function(request);
               match request {
                 prod  => "p",
                 dev => "d",
                 test => "t"
               }
            "#;

            let expr = Expr::from_text(expr).unwrap();
            let compiler =
                RibCompiler::new(RibCompilerConfig::new(analysed_exports, vec![], vec![]));
            let compiled = compiler.compile(expr).unwrap();
            let expected_type_info =
                internal::rib_input_type_info(vec![("request", request_value_type)]);

            assert_eq!(compiled.rib_input_type_info, expected_type_info);
        }

        #[test]
        async fn test_record_global_input() {
            let request_value_type =
                record(vec![field("path", record(vec![field("user", str())]))]);

            let output_analysed_type = str();

            let analysed_exports = internal::get_component_metadata(
                "my-worker-function",
                vec![request_value_type.clone()],
                output_analysed_type,
            );

            // x = request, implies we are expecting a global variable
            // called request as the  input to Rib.
            // my-worker-function is a function that takes a Record of path -> user -> str as input
            // implies the type of request is a Record.
            // This means the rib interpreter env has to have a request variable in it,
            // with a value that should be of the type Record
            let expr = r#"
               let x = request;
               let worker = instance();
               worker.my-worker-function(x);

               let name = x.path.user;

               match x {
                 { path : { user : some_name } } => some_name,
                 _ => name
               }
            "#;

            let expr = Expr::from_text(expr).unwrap();
            let compiler =
                RibCompiler::new(RibCompilerConfig::new(analysed_exports, vec![], vec![]));
            let compiled = compiler.compile(expr).unwrap();
            let expected_type_info =
                internal::rib_input_type_info(vec![("request", request_value_type)]);

            assert_eq!(compiled.rib_input_type_info, expected_type_info);
        }

        #[test]
        async fn test_tuple_global_input() {
            let request_value_type = tuple(vec![str(), u32(), record(vec![field("user", str())])]);

            let output_analysed_type = str();

            let analysed_exports = internal::get_component_metadata(
                "my-worker-function",
                vec![request_value_type.clone()],
                output_analysed_type,
            );

            // x = request, implies we are expecting a global variable
            // called request as the  input to Rib.
            // my-worker-function is a function that takes a Tuple,
            // implies the type of request is a Tuple.
            let expr = r#"
               let x = request;
               let worker = instance();
               worker.my-worker-function(x);
               match x {
                (_, _, record) =>  record.user,
                 _ => "fallback"
               }
            "#;

            let expr = Expr::from_text(expr).unwrap();
            let compiler =
                RibCompiler::new(RibCompilerConfig::new(analysed_exports, vec![], vec![]));
            let compiled = compiler.compile(expr).unwrap();
            let expected_type_info =
                internal::rib_input_type_info(vec![("request", request_value_type)]);

            assert_eq!(compiled.rib_input_type_info, expected_type_info);
        }

        #[test]
        async fn test_list_global_input() {
            let request_value_type = list(str());

            let output_analysed_type = str();

            let analysed_exports = internal::get_component_metadata(
                "my-worker-function",
                vec![request_value_type.clone()],
                output_analysed_type,
            );

            // x = request, implies we are expecting a global variable
            // called request as the  input to Rib.
            // my-worker-function is a function that takes a List,
            // implies the type of request should be a List
            let expr = r#"
               let x = request;
               let worker = instance();
               worker.my-worker-function(x);
               match x {
               [a, b, c]  => a,
                 _ => "fallback"
               }
            "#;

            let expr = Expr::from_text(expr).unwrap();
            let compiler =
                RibCompiler::new(RibCompilerConfig::new(analysed_exports, vec![], vec![]));
            let compiled = compiler.compile(expr).unwrap();
            let expected_type_info =
                internal::rib_input_type_info(vec![("request", request_value_type)]);

            assert_eq!(compiled.rib_input_type_info, expected_type_info);
        }
    }

    mod internal {
        use crate::wit_type::*;
        use crate::wit_type::{case, str, u64, unit_case, variant};
        use crate::{ComponentDependency, ComponentDependencyKey, RibInputTypeInfo};
        use std::collections::HashMap;
        use uuid::Uuid;

        pub(crate) fn metadata_with_variants() -> ComponentDependency {
            let instance = WitExport::Interface(WitInterface {
                name: "golem:it/api".to_string(),
                functions: vec![WitFunction {
                    name: "foo".to_string(),
                    parameters: vec![WitFunctionParameter {
                        name: "param1".to_string(),
                        typ: variant(vec![
                            case("register-user", u64()),
                            case("process-user", str()),
                            unit_case("validate"),
                        ]),
                    }],
                    result: Some(WitFunctionResult {
                        typ: WitType::Handle(TypeHandle {
                            resource_id: AnalysedResourceId(0),
                            mode: AnalysedResourceMode::Owned,
                            name: None,
                            owner: None,
                        }),
                    }),
                }],
            });

            let component_info = ComponentDependencyKey {
                component_name: "foo".to_string(),
                component_id: Uuid::new_v4(),
                component_revision: 0,
                root_package_name: None,
                root_package_version: None,
            };

            ComponentDependency::from_wit_metadata(component_info, &[instance]).unwrap()
        }

        pub(crate) fn get_component_metadata(
            function_name: &str,
            input_types: Vec<WitType>,
            output: WitType,
        ) -> ComponentDependency {
            let analysed_function_parameters = input_types
                .into_iter()
                .enumerate()
                .map(|(index, typ)| WitFunctionParameter {
                    name: format!("param{index}"),
                    typ,
                })
                .collect();

            let component_info = ComponentDependencyKey {
                component_name: "foo".to_string(),
                component_id: Uuid::new_v4(),
                component_revision: 0,
                root_package_name: None,
                root_package_version: None,
            };

            let exports = vec![WitExport::Function(WitFunction {
                name: function_name.to_string(),
                parameters: analysed_function_parameters,
                result: Some(WitFunctionResult { typ: output }),
            })];
            ComponentDependency::from_wit_metadata(component_info, &exports).unwrap()
        }

        pub(crate) fn rib_input_type_info(types: Vec<(&str, WitType)>) -> RibInputTypeInfo {
            let mut type_info = HashMap::new();
            for (name, typ) in types {
                type_info.insert(name.to_string(), typ);
            }
            RibInputTypeInfo { types: type_info }
        }
    }
}