Custom keyword modifying data doesn't run during parsing

[bohdyone]

Hi, I'm trying to parse to a custom type, but running into some issues.

What version of Ajv are you using? Does the issue happen if you use the latest version?
"ajv": "^8.11.0"

Ajv options object

const parseDecimalKeyword: KeywordDefinition = {
  keyword: "parseDecimal",
  compile: () => (data, dataCtx: DataValidationCxt) => {
    const parsedDecimal = new BigNumber(data, 10);
    dataCtx.parentData[dataCtx.parentDataProperty] = parsedDecimal;

    return !parsedDecimal.isNaN();
  },
};

const ajv = new Ajv({
  keywords: [parseDecimalKeyword],
});

JSON Schema

{
  elements: {
    properties: {
      amount: <any>{
        type: "string",
        metadata: {
          parseDecimal: true,
        },
      },
    },
    additionalProperties: true,
  },
};

Sample data

const test = [
      {
        id: 'DeQtD(X%t}',
        creationTime: '2072-12-24T10:35:22.962Z',
        description: '*N)`v1;#M8',
        assetName: 'g+}rw`6zi)',
        amount: '57136.58',
        balance: '81053.34',
        type: 'Withdraw',
        recordType: 'Trade',
        referenceId: '}AEcK*GK*P'
      }
]

const result = parseBtcMarketsTxsRspData(JSON.stringify(test))!;
  expect(parseBtcMarketsTxsRspData.message).toBeUndefined();
  expect(result).not.toBeUndefined();

  expect(result).toHaveLength(1);
  expect(result[0].amount).toBeInstanceOf(BigNumber);

What results did you expect?

Based on the examples in #141 I expect to have the value of amount parsed to a BigNumber object if successful, but it seems like it's still a string.

Btw, it seems like I also have to cast the property object in schema to to satisfy the type checking even though I will be coercing the value from string to BigNumber. Is there a plan to address this limitation / support this use case?

Are you going to resolve the issue?

If there is a more appropriate way to do this, I'm happy to. Right now I have to work around it by using validate() instead of parse() directly.

[semiaddict]

I believe your schema should be as follows (without the metadata key):

{
  elements: {
    properties: {
      amount: <any>{
        type: "string",
        parseDecimal: true,
      },
    },
    additionalProperties: true,
  },
};

[bohdyone]

Forgot to say, this is a JTD schema not a JSON Schema, so extra keywords are only allowed under the metadata prop...

[bohdyone]

Hi, Is there any update on this one?

Regards.

[epoberezkin]

Sorry for the delay.

Keywords that modify data have to be explicitly marked as such (modifying: true), otherwise they won't update the object with the data, they would simply update the local variable.

See this doc: https://ajv.js.org/api.html#ajv-addkeyword-definition-object-ajv

[epoberezkin]

although, you are explicitly updating parent data...

[bohdyone]

Hi,

Thanks for the reply.

although, you are explicitly updating parent data...

I'm only doing that in this case because I want to replace the value of data. Is there a more idiomatic way of doing that?

Regards,
Bogdan.