Improvement: Display detailed messages when validation fails

[AM1988]

Discussed in https://github.com/ajv-validator/ajv/discussions/2497

^{Originally posted by AM1988 October 4, 2024} Hi there.

I have a class for data validation `export class SchemaValidator { static ajv = new Ajv({ allErrors: true, verbose: true });

public static validate<T>(schema: SchemaFile, data: T): boolean {
    const schemaContent = JSON.parse(fs.readFileSync(path.join(__dirname, 'path', schema), 'utf-8'));
    if (!this.ajv.validateSchema(schemaContent)) {
        console.error(`Schema is not valid.`);
    }
    const isValid = this.ajv.validate(schemaContent, data);

    if (!isValid) {
        const errorMessages = this.ajv.errorsText();
        logger.error(`Validation failed : ${errorMessages}`);
        return false;
    }
    return true;
}

}` I use JSON schema described in a separate file. How to get the full output when validation fails so that I can understand which part exactly does not match?

For example, values in the enum did not match, or input data had some additional properties, missing properties, etc.

Right now I see only data.payload.something should be equal to one of the allowed values

It does not have info about original data that does not pass schema validation.

It returns messages like data.sources[0].version should match pattern "^.{555}$", data.sources[1].version should match pattern "^.{555}$", data.sources[2].version should match pattern "^.{555}$" but you have no clue what exactly data.sources[0].version is.