Create a conditional statement based on the properties of an object

Question

Create a conditional statement based on the properties of an object

In one of my Typescript projects, I am faced with the task of constructing a dynamic 'if' statement based on the data received from an object. The number of conditions in this 'if' statement should match the number of properties present in the object.

Here is the initial object:

interface EmailParams { 
  sender?: string,
  subject?: string,
  fileType?: string
}

let params: EmailParams = {
  sender: "<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="720617010632151f131b1e5c111d1f">[email protected]</a>"
}

This is the condition that needs to be met:

if (test1.from.toUpperCase() == params.sender?.toUpperCase())

If there are changes made to the object, here is the updated version:

interface EmailParams { 
  sender?: string,
  subject?: string,
  fileType?: string
}

let params: EmailParams = {
  sender: "<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="4c38293f380c2b212d2520622f2321">[email protected]</a>",
  subject: "data"
}

The new 'if' statement should now look like this:

if (test1.from.toUpperCase() == params.sender?.toUpperCase() &&
    test1.data.toUpperCase() == params.subject?.toUpperCase()
)

arrays typescript

Answer 1

Answer №1

To achieve this, a common approach is to follow these steps:

const properties: (keyof EmailParams)[] = [
  'sender',
  'subject',
];

const sampleData = {
  data: "whatever",
  from: "foobar",
};

const mapping: {
  [k in keyof EmailParams]: keyof typeof sampleData
} = {
  subject: 'data',
  sender: 'from',
}

const compareEmailParams = (obj: EmailParams): boolean => {
  return properties.every((k: keyof EmailParams) => {
    if (k in mapping) {
      const key: keyof typeof sampleData = mapping[k] as keyof typeof sampleData;
      return obj[k]?.toUpperCase() === sampleData[key].toUpperCase();
    }
    return true; 
  });
};

console.log(compareEmailParams(params));

If you need to add a new property, remember to update the list of keys and the mapping between email params and sample data.

This approach offers several advantages, such as easier unit testing without relying on conditional logic and the ability to reuse the function in different parts of the codebase.

Playground

Answer 2

To achieve this, a common approach is to follow these steps:

const properties: (keyof EmailParams)[] = [
  'sender',
  'subject',
];

const sampleData = {
  data: "whatever",
  from: "foobar",
};

const mapping: {
  [k in keyof EmailParams]: keyof typeof sampleData
} = {
  subject: 'data',
  sender: 'from',
}

const compareEmailParams = (obj: EmailParams): boolean => {
  return properties.every((k: keyof EmailParams) => {
    if (k in mapping) {
      const key: keyof typeof sampleData = mapping[k] as keyof typeof sampleData;
      return obj[k]?.toUpperCase() === sampleData[key].toUpperCase();
    }
    return true; 
  });
};

console.log(compareEmailParams(params));

If you need to add a new property, remember to update the list of keys and the mapping between email params and sample data.

This approach offers several advantages, such as easier unit testing without relying on conditional logic and the ability to reuse the function in different parts of the codebase.

Playground

Create a conditional statement based on the properties of an object

Answer №1

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