[@loopback/sequelize] Entity with JSON data is not parsed to an object when using MySQL / MariaDB about loopback-next

[shubhamp-sf]

Thanks for reporting this @KalleV, It seems sequelize relies on the actual db column type for the parsing. As I tried it with postgres and as long as the datatype in db is set to character varying the json in raw format is what I get otherwise it's is stringified.
It's not respecting the JSON defined in the model definition.

As a solution for data type disparity puting this parsing logic into this extension to match the behaviour of different loopback-connectors sounds cumbersome but will what best I can do to match it.

[shubhamp-sf]

Also when you say:

I tried adding a getter to all entity JSON properties...

Where did you add that in your LoopBack app?

[KalleV]

I defined the custom getter using the "sequelizeOptions" hooks. Something like this:

sequelizeOptions: {
  hooks: {
    beforeDefine: (attributes, options) => {
      // ...

      Object.keys(attributes).forEach((key) => {
        const attribute = attributes[key];
        if (
          typeof attribute !== 'string' &&
          'type' in attribute &&
          attribute.type === DataTypes.JSON
        ) {
          Object.assign(attribute, {
            get() {
              const value = this.getDataValue(key);

              if (typeof value === 'string') {
                try {
                  return JSON.parse(value);
                } catch (error) {
                  /* log error */
                  return null;
                }
              }
              return value;
            }
          });
        }
      });
    }
  },
  // ...