Format schema with oneOf doesn't work correctly

[avkos]

const schema = {
  type: 'object',
  properties: {
    from: {
      format: 'address',
    },
    to: {
      oneOf: [{ format: 'string' }, { type: 'null' }],
    },
  },
};

const data = {
  from: '0x7ed0e85b8e1e925600b4373e6d108f34ab38a401',
  to: 123,
};

const res = format(schema, data);

// res { from: '0x7ed0e85b8e1e925600b4373e6d108f34ab38a401', to: 123 }

Actual Behaviour:
to is not formatted

Expected Behaviour:
to should be formatted to a string

[Franklin-Osede]

Hello, I would like to contribute to resolve this issue. Thanks

[mmyyrroonn]

@Franklin-Osede Hi, are you working on this issue? I want to take over it if you're not yet. 😄

[mconnelly8]

Hey @mmyyrroonn, it doesn't look like @Franklin-Osede is working on this. Please go ahead and work on this one. We appreciate you wanting to help out.

[mmyyrroonn]

@avkos @mconnelly8 Hi, after debugging the code, I found the root cause.

The schemaProp would be {"oneOf":[{"format":"string"},{"type":"null"}]} during parsing the to property, which does not have format property. The covertScalarValue would throw an error and skip this property. The code path for this situation is missing in the current codebase.

web3.js/packages/web3-utils/src/formatter.ts

Line 325 in 89711ab

object[key] = convertScalarValue(value, schemaProp.format as string, format);

Here are three ways to fix this bug in my mind.

• fix it in the convertScalarValue function
• fix it in the findSchemaByDataPath function
• fix it in the convert function by adding extra logic, targeting this bug

I would like to know more about this bug and its background before I start my PR. Is there any guideline we should follow for the oneOf keyword? For example, if the schema is to: {oneOf: [{ format: 'string' }, { format: 'number' }],},, what should we do?

[luu-alex]

Hey there @mmyyrroonn thanks for taking a look into this :) to: {oneOf: [{ format: 'string' }, { format: 'number' }],} I haven't dived into the formatter too much, but i dont believe this should be possible, maybe im not understanding why it would have these two different types of format?

[mmyyrroonn]

Hey there @mmyyrroonn thanks for taking a look into this :) to: {oneOf: [{ format: 'string' }, { format: 'number' }],} I haven't dived into the formatter too much, but i dont believe this should be possible, maybe im not understanding why it would have these two different types of format?

Hi, I'm glad to hear your response. I'm not familiar with the schema. what is the definition of the keyword oneOf? The above example may be a wrong or invalid schema according to my personal understanding of the word oneOf. It's much better if there is a doc I can check to follow. Right now, I understand why the situation happened this way. However, I’m unsure about the correct code logic for this keyword. I don't want to fix a bug by creating a new one 😄