Use OpenAPI v3 spec to coerce primitives in query, path and headers

[shimks]

Story

As a LoopBack4 user, I would like to be able to validate primitive types in my http request.

connected to #118

Acceptance Criteria

• Coerce incoming query string, path and header inputs into strings, numbers, booleans, Dates
  • Do not coerce timestamps (Unix timestamps in milliseconds)
• Validate only that the output is correct for the chosen type

Notes

We should consider using either strong-remoting or AJV to perform the coercion

packages/example-getting-started/src/controllers/todo.controller.ts should be updated to remove the manual coercion once this issue is fixed! (Also update the related docs for the tutorial!)

Coercion is closely related to validation, see #118

A list of coming PRs for edge cases:

• boolean
  • comment1
• date
  • comment1
• buffer
• integer

Edge cases that should apply to all types:

• An empty string
• Value not provided (header missing, no query string argument with the given name, etc.)
• An invalid value

[bajtos]

@kjdelisle and me agreed to remove Validation from MVP scope. The current validation performed by Juggler should be good enough for CRUD applications which are our MVP target.

[virkt25]

packages/example-getting-started/src/controllers/todo.controller.ts should be updated to remove the manual coercion once this issue is fixed! (Also update the related docs for the tutorial!).

[jannyHou]

A list of coming PRs for edge cases:

• boolean
  • comment1
• date
  • comment1

keep adding more types

[bajtos]

@jannyHou in addition to the list you have above, there should be a test for each OAS type to verify how the following input values are handled:

• An empty string
• Value not provided (header missing, no query string argument with the given name, etc.)
• An invalid value

[jannyHou]

closing it after 2 PRs checked in