Repeated or duplicated properties in schemas

[sitetester]

https://github.com/LiskHQ/lips/blob/main/proposals/lip-0061.md#schema

unsignedCertificateSchema = {
    "type": "object",
    "required": [
        "blockID",
        "height",
        "timestamp",
        "stateRoot",
        "validatorsHash"
    ],
    "properties": {
        "blockID": {
            "dataType": "bytes",
            "length": HASH_LENGTH,
            "fieldNumber": 1
        },
        "height": {
            "dataType": "uint32",
            "fieldNumber": 2
        },
        "timestamp": {
            "dataType": "uint32",
            "fieldNumber": 3
        },
        "stateRoot": {
            "dataType": "bytes",
            "length": HASH_LENGTH,
            "fieldNumber": 4
        },
        "validatorsHash": {
            "dataType": "bytes",
            "length": HASH_LENGTH,
            "fieldNumber": 5
        }
    }
}

certificateSchema = {
    "type": "object",
    "required": [
        "blockID",
        "height",
        "timestamp",
        "stateRoot",
        "validatorsHash",
        "aggregationBits",
        "signature"
    ],
    "properties": {
        "blockID": {
            "dataType": "bytes",
            "length": HASH_LENGTH,
            "fieldNumber": 1
        },
        "height": {
            "dataType": "uint32",
            "fieldNumber": 2
        },
        "timestamp": {
            "dataType": "uint32",
            "fieldNumber": 3
        },
        "stateRoot": {
            "dataType": "bytes",
            "length": HASH_LENGTH,
            "fieldNumber": 4
        },
        "validatorsHash": {
            "dataType": "bytes",
            "length": HASH_LENGTH,
            "fieldNumber": 5
        },
        "aggregationBits": {
            "dataType": "bytes",
            "fieldNumber": 6
        },
        "signature": {
            "dataType": "bytes",
            "length": BLS_SIGNATURE_LENGTH,
            "fieldNumber": 7
        }
    }
}

Just like in LIP 45, we used ... notation to merge external schema, we can do the same here to merge repeated properties from unsignedCertificateSchema

One example:
https://github.com/LiskHQ/lips/blob/main/proposals/lip-0045.md#data-3

ccmProcessedDataSchema = {
    "type": "object",
    "required": ["ccm", "result", "code"],
    "properties": {
        "ccm": {
            ...crossChainMessageSchema,
            "fieldNumber": 1
        },
        "result": {
            "dataType": "uint32",
            "fieldNumber": 2
        },
        "code": {
            "dataType": "uint32",
            "fieldNumber": 3
        }
    }
}

Also we can add this text below updated schema:

Here, the ... notation, borrowed from JavaScript ES6 data destructuring, indicates that the corresponding schema should be inserted in place, and it is just used for notational convenience.

Note: Above text is taken from https://github.com/LiskHQ/lips/blob/main/proposals/lip-0045.md#genesis-assets-schema, which is written under the schema.

[janhack]

@sitetester I agree for nested objects, it is nice and clean to just use the ... notation. However, in this case here we need to add two elements to the "required" array and "properties" array and do not just define a nested sub-schema. Therefore, I am not sure that it would be that clean in this case.

[sitetester]

Hi, thank you for asking question & clarifying ambiguity!
Yes, we can deal with repeated properties in required section also. In fact, it's already managed in current code.

export const certificateSchema = {
	type: 'object',
	required: [...unsignedCertificateSchema.required, 'aggregationBits', 'signature'],
	properties: {
		...unsignedCertificateSchema.properties,
		aggregationBits: {
			dataType: 'bytes',
			fieldNumber: 6,
		},
		signature: {
			dataType: 'bytes',
			minLength: BLS_SIGNATURE_LENGTH,
			maxLength: BLS_SIGNATURE_LENGTH,
			fieldNumber: 7,
		},
	},
};

It's all good like this. We should avoid repetition as much as possible.

[janhack]

Nice, thanks for the reference. I will update the LIP accordingly.

[janhack]

I think we could do the same change for the block header schema https://github.com/LiskHQ/lips/blob/main/proposals/lip-0055.md#unsigned-block-header-json-schema. I generalized the issue name accordingly.