Async @postConstruct/onActivation + @preDestroy/onDeactivation

[parisholley]

For anyone wanting to play around with this, you can use the NPM release:

@parisholley/inversify-async:1.0.20

In continuation of #1074, allowing async hooks into dependency lifecycles.

Description

Global onActivation

container.onActivation('asyncIdentifier', (context, injectable) => {
  return Promise.resolve('newObject'); // returning a promise enforces use of getAsync(), even if future binds are not async
});
container.bind('asyncIdentifier').toConstantValue('foobar');

await container.getAsync('asyncIdentifier');

container.onActivation('syncIdentifier', (context, injectable) => {
  return 'newObject'; // no promise = use legacy API
});

container.get('syncIdentifier');

Binding onActivation

container.bind('asyncIdentifier').toConstantValue('foobar').onActivation((context, injectable) => {
  return Promise.resolve('newObject'); // returning a promise enforces use of getAsync()
});

await container.getAsync('asyncIdentifier');

container.bind('asyncIdentifier').toConstantValue('foobar').onActivation((context, injectable) => {
  return 'newObject'; // no promise = use legacy API
});

container.get('syncIdentifier');

Parent/Child onActivation

container.onActivation('asyncIdentifier', (context, injectable) => {
  return Promise.resolve('newObject'); // returning a promise enforces use of getAsync()
});

const child = container.createChild();
child.bind('asyncIdentifier').toConstantValue('foobar');

await container.getAsync('asyncIdentifier');

Module onActivation

container.bind('asyncIdentifier').toConstantValue('foobar');

const TestContainerModule = new ContainerModule((bind, unbind, isBound, rebind, onActivation) => {
  onActivation('asyncIdentifier', async (context, service) => {

 }));
});

Related Issue

#551
#1074
#471

Motivation and Context

For testing (or perhaps a custom request based framework where child containers are created for each web request to implement "Request Scope" similar to spring), it may be useful to have async construct/destroy methods. For example, a web request where we want to run all service calls in a transaction and commit on at the end (by unbinding the container), or in tests by rolling back database changes for more performant runs.

How Has This Been Tested?

Similar to test cases for #1074, ensure that errors are thrown when mixing sync and async APIs.

Types of changes

• Updated docs / Refactor code / Added a tests case (non-breaking change)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have updated the changelog.

[parisholley]

closing and continuing with #1132