Log-My-Food CLI app

#! /usr/bin/env node

const { default: axios } = require('axios');

const readline = require('readline').createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'enter command > '
})

readline.prompt();
// Line event listener
readline.on('line', async (line) => {
    switch (line.trim()) {
        case 'log':
            {
                const { data } = await axios.get(`http://localhost:3001/food`)
                const it = data[Symbol.iterator]();
                let actionIt;

                const actionIterator = {
                    [Symbol.iterator]() {
                        const positions = [...this.actions];
                        return {
                            [Symbol.iterator]() {
                                return this;
                            },
                            next(...args) {
                                if (positions.length > 0) {
                                    const position = positions.shift();
                                    const result = position(...args);
                                    return { value: result, done: false }
                                } else {
                                    return { done: true }
                                }

                            }
                        }
                    },
                    actions: [
                        askForServingSize,
                        displayCalories
                    ],
                };

                function askForServingSize(food) {
                    readline.question("How many servings did you eat? (enter as a decimal)",
                        servingSize => {
                            actionIt.next(servingSize, food)
                        }
                    );
                }

                function displayCalories(servingSize, food) {
                    const cals = food.calories
                    console.log(`${food.name} with a serving size of ${servingSize} has ${Number.parseFloat(cals * parseFloat(servingSize)).toFixed(2)} calories.`)
                    actionIt.next();
                    readline.prompt();
                }


                readline.question(`What you would like to log today?`, async (item) => {
                    let position = it.next(); // returns an object with a value property and a done property

                    while (!position.done) {
                        const food = position.value;
                        if (food.name === item) {
                            console.log(`${item} has ${food.calories} calories per ${food.serving_size} ${food.serving_size_units}`);
                            actionIt = actionIterator[Symbol.iterator]();
                            actionIt.next(food);
                        }
                        position = it.next()

                    }
                    console.log(`You have entered ${item}`)
                    readline.prompt();
                });
            }
            break;
        case 'list vegan foods':
            {
                console.log('vegan food list')
                axios.get(`http://localhost:3001/food`).then(({ data }) => {
                    const veganOnly = data.filter(food => {
                        return food.dietary_preferences.includes('vegan');
                    })
                    let idx = 0;
                    const veganIterable = {
                        [Symbol.iterator]() {
                            return {
                                [Symbol.iterator]() {
                                    return this;
                                },
                                next() {
                                    const current = veganOnly[idx];
                                    idx++;
                                    if (current) {
                                        return { value: current, done: false };
                                    } else {
                                        return { value: current, done: true };
                                    }
                                },
                            };
                        },
                    };
                    for (let val of veganIterable) {
                        console.log(val.name);
                    }
                    readline.prompt()
                });
            }
            break;
    }

})