How do I merge additional properties into an object stored in localStorage?

The error occurs because you are assuming that the parsed data is an array and trying to use the array method push; in your case, it’s an object. You want to merge the picture and fullname values into the "test-params" object rather than adding an element to an array.

Here’s how you can fix it:

1. Parse the existing "test-params" from local storage.
2. Merge the new properties into this object.
3. Save the updated object back to local storage.

Below is an example implementation:

JAVASCRIPTCopied
// Example input data (ensure this is defined correctly)
var inputData = {
  name: "Junk",
  picture: "two"
};

// Create new properties
var newProps = {
  fullname: inputData.name,
  picture: '<img src="'+ inputData.picture +'" />'
};

// Retrieve and parse the existing "test-params". This is an object.
var testParams = JSON.parse(localStorage.getItem("test-params"));

// Use Object.assign to merge testParams and new properties.
// If testParams might be null, provide a default empty object.
var merged = Object.assign({}, testParams, newProps);

// Save the merged object back to local storage
localStorage.setItem("test-params", JSON.stringify(merged));

Explanation

• Parsing and Merging:
  Instead of expecting an array (and using push), we retrieve the object via JSON.parse. Then, we use Object.assign to merge the new properties (fullname and picture) with the existing properties in the test-params object.

• Local Storage Key:
  Note that in your local storage example the key is "test-params" rather than "oauth2-test-params". Ensure you use the correct key when getting and setting the data.

• Stringifying:
  The merged object is then stringified using JSON.stringify before saving it back to local storage.

This approach adds the desired properties into the existing "test-params" object rather than assuming it’s an array.