Type alias ContainerConflictStrategy

A description of how TypeDI should react when a container with the specified ID already exists in the registry.

There are three possible values:

• throw: Throw an error upon conflict.
• null: Return null.
• returnExisting: Return the existing container.

If you pass a ContainerConflictDefinition without this, it will default to throw. Otherwise, returnExisting is the default.

Example

Review the following:

ContainerInstance.of('my-container', defaultContainer, {
  onConflict: 'throw'
});
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Remarks

Be aware that when returnExisting is used, you may encounter unexpected errors if containers with completely different configurations have the same ID. Therefore, it is discouraged in most situations. However, for historical reasons, it remains the default.

Consider the following example:

ContainerInstance.of('my-container', null); // Create an orphaned container.
defaultContainer.ofChild('my-container'); // Create a child container.
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In the case of returnExisting, the call to ContainerInstance.ofChild would return a reference to the orphaned container, which will cause unexpected runtime errors when your code is unable to resolve symbols from the parent container.

As such, when returnExisting is utilised, it is heavily recommended to use unique symbol IDs that are unique to a certain part of your application.