Feature: Response sampling

[oscar60310]

https://www.notion.so/canner/API-response-sampling-88093cca3a8b41aab90d3a0b1cbafde9

User story

1. User definitions.

   -- YAML
   exampleParameter:
       userId: 1111
   -- SQL
   select * from users where id = '{{ context.params.userId }}';

2. We’ll send queries while building.

   select * from users where id = '1111';

3. After sample query responses, we transform and append the response.

   response:
     - name: id
       type: STRING
   ....

4. (Existed feature) Generate document from schema.

Commits

1. 3c18dae Pass pagination config into compiler.
2. 35905a3 Refactor: In order to access template engine from middleware, I update middleware from pure functions to injectable classes.
3. 2058470 Load compiled data right after compiling because we'll send sample queries while building schema.
4. d30e700 Sampler implementation. I send the main query with offset/limit pagination:

       const response = await this.templateEngine.execute(
         schema.templateSource,
         { context: { params: schema.exampleParameter } },
         // We only need the columns of this query, so we set offset/limit both to 0 here.
         {
           limit: 0,
           offset: 0,
         }
       );
   Maybe there is a better solution to get the columns.

[kokokuo]

Excellent, LGTM 👍

[kokokuo]

Great and clear way through IoC solution to inject 👍 (also make me could refer in my code refactor 😃 )

[kokokuo]

Maybe we could add a comment to let other members know the array order will become the compose order for middleware executing, or if other members modified the order and some middleware have the relationship of reading/writing data, it will have some influence.

[oscar60310]

Sure, I've added.

// The order of middleware here indicates the order of their execution, the first one will be executed first, and so on.
export const SchemaParserMiddlewares: ClassType<SchemaParserMiddleware>[] = [
  GenerateUrl,
  CheckValidator,
  TransformValidator,
  GenerateTemplateSource,
  CheckParameter,
  AddMissingErrors,
  FallbackErrors,
  NormalizeFieldIn,
  GenerateDataType,
  NormalizeDataType,
  GeneratePathParameters,
  AddRequiredValidatorForPath,
  SetConstraints,
  ResponseSampler,
];

[oscar60310]

Hi @kokokuo , thanks for reviewing, all issues have been fixed.