Define the HookContext as a partial view of the HRE

[alcuadrado]

This PR addresses a limitation in Hardhat's core architecture discovered by @ChristopherDedominici.

Explanation of the problem

Chris is working on the first few hook handlers that use the builtin plugins, and in particular, the extensions to the HRE that they make.

This was problematic, as HookHandlers don't receive the HRE, but a HookContext instead. The problem was that any extension to the HRE wasn't reflected in the HookContext.

The' HookContext' intends to prevent HookHandler's from accessing the TaskManager and running tasks, as these are separate concerns in v3, and not to prevent them from accessing the builtin plugins.

Proposed solution

This solution has a type-level and runtime-level component.

Types

Instead of defining the HookContext as a separate interface, define it as a derived type of the HRE:

export type HookContext = Omit<HardhatRuntimeEnvironment, "tasks">;

This way, every extension to the HardhatRuntimeEnvironment is also available in the HookContext.

Runtime

To make the values (as in runtime values, not types) of the extensions available through the HookContext, without creating a new hook nor restructuring the system, I used Object.create to create the HookContext, and overwrote tasks with undefined.

Contrary to making a shallow copy at initialization, defining the HRE as its prototype means that any future modification to the HRE will also be visible.

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Latest commit: 46d675d

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Name	Status	Preview	Comments	Updated (UTC)
hardhat	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Sep 25, 2024 7:29pm

[schaable]

Looks good! Using Object.create was really smart 💯