feat: add ChainController (#4227)

## Explanation This new controller will be responsible of exposing Snaps that implement the newly defined Chain API. This controller also implements the chain API itself. Reference: https://github.com/MetaMask/chain-api/ ## Changelog ### `@metamask/chain-controller` - **Added**: New `ChainController`: exposes/interacts with chain API providers ## Checklist - [x] I've updated the test suite for new or updated code as appropriate - [x] I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate - [x] I've highlighted breaking changes using the "BREAKING" category above as appropriate --------- Co-authored-by: Elliot Winkler <[email protected]> Co-authored-by: Gustavo Antunes <[email protected]>
MetaMask · May 20, 2024 · 2752a88 · 2752a88
1 parent e3929c9
commit 2752a88
Show file tree

Hide file tree

Showing 18 changed files with 934 additions and 0 deletions.
diff --git a/README.md b/README.md
@@ -15,6 +15,7 @@ This repository contains the following packages [^fn1]:
 - [`@metamask/assets-controllers`](packages/assets-controllers)
 - [`@metamask/base-controller`](packages/base-controller)
 - [`@metamask/build-utils`](packages/build-utils)
+- [`@metamask/chain-controller`](packages/chain-controller)
 - [`@metamask/composable-controller`](packages/composable-controller)
 - [`@metamask/controller-utils`](packages/controller-utils)
 - [`@metamask/ens-controller`](packages/ens-controller)
@@ -58,6 +59,7 @@ linkStyle default opacity:0.5
   assets_controllers(["@metamask/assets-controllers"]);
   base_controller(["@metamask/base-controller"]);
   build_utils(["@metamask/build-utils"]);
+  chain_controller(["@metamask/chain-controller"]);
   composable_controller(["@metamask/composable-controller"]);
   controller_utils(["@metamask/controller-utils"]);
   ens_controller(["@metamask/ens-controller"]);
@@ -97,6 +99,7 @@ linkStyle default opacity:0.5
   assets_controllers --> network_controller;
   assets_controllers --> polling_controller;
   assets_controllers --> preferences_controller;
+  chain_controller --> base_controller;
   composable_controller --> base_controller;
   composable_controller --> json_rpc_engine;
   ens_controller --> base_controller;

diff --git a/packages/chain-controller/CHANGELOG.md b/packages/chain-controller/CHANGELOG.md
@@ -0,0 +1,10 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+[Unreleased]: https://github.com/MetaMask/core/
diff --git a/packages/chain-controller/LICENSE b/packages/chain-controller/LICENSE
@@ -0,0 +1,20 @@
+MIT License
+
+Copyright (c) 2024 MetaMask
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
diff --git a/packages/chain-controller/README.md b/packages/chain-controller/README.md
@@ -0,0 +1,102 @@
+# `@metamask/chain-controller`
+
+Manages chain-agnostic providers implementing the chain API.
+
+## Installation
+
+`yarn add @metamask/chain-controller`
+
+or
+
+`npm install @metamask/chain-controller`
+
+## Contributing
+
+This package is part of a monorepo. Instructions for contributing can be found in the [monorepo README](https://github.com/MetaMask/core#readme).
+
+## Description
+
+This controller is responsible to "bridge" Snaps that implements the [Chain API] and a MetaMask
+client.
+
+The controller maps a "chain provider" to its CAIP-2 (chain id) identifier
+(named `scope` in the [Chain API]).
+The MetaMask client can then use an external source (outside for current controllers that
+only support EVM networks) to fetch information from a non-EVM network.
+
+The controller itself also implements the [Chain API]. Its uses the `scope` (that is always
+required for any methods) to identify the chain provider and then forward the method call to this
+provider.
+
+The calls are dispatched through the `SnapsController:handleRequest`'s action.
+
+Here's the high-level flow when invoking a [Chain API]'s method:
+
+```mermaid
+%%{init: {"flowchart": {"htmlLabels": false}}}%%
+sequenceDiagram
+  autonumber
+
+  participant MetaMask
+  participant ChainController
+  participant Snap
+
+
+  box Metamask Client
+    participant MetaMask
+    participant ChainController
+  end
+
+  MetaMask -> Snap: Retrieves Snap ID
+  MetaMask ->> ChainController: registerProvider(scope, snapId)
+  note over MetaMask,Snap: Provider must be registered first
+
+
+  MetaMask ->> ChainController: chain_method(scope, ...)
+  activate MetaMask
+
+  alt If there is a chain client for this scope
+      ChainController ->> ChainController: client = getProviderClient(scope)
+
+      ChainController ->> Snap: client.chain_method(scope, ...)
+      Snap ->> Snap: Process Chain API request
+      Snap -->> ChainController: Chain API response
+  end
+
+  ChainController -->> MetaMask: Chain API Response
+
+  deactivate MetaMask
+```
+
+Clients and Snap interactions:
+
+```mermaid
+%%{init: {"flowchart": {"htmlLabels": false}}}%%
+sequenceDiagram
+  autonumber
+
+  participant ChainController
+  participant SnapChainProviderClient
+  participant SnapHandlerClient
+  participant SnapsController
+
+  ChainController ->> SnapChainProviderClient: chain_method(scope, ...)
+  activate ChainController
+
+  note over SnapChainProviderClient: This client also implements the Chain API methods
+
+  SnapChainProviderClient ->> SnapHandlerClient: submitRequest({ snapId, origin, handler, request })
+
+  SnapHandlerClient ->> SnapsController: :handleRequest(...)
+  SnapsController -->> SnapHandlerClient: Response
+
+  SnapHandlerClient -->> SnapChainProviderClient: Response
+
+  SnapChainProviderClient -->> ChainController: Response
+
+  deactivate ChainController
+```
+
+## Resources
+
+- [Chain API](https://github.com/MetaMask/chain-api/)
diff --git a/packages/chain-controller/jest.config.js b/packages/chain-controller/jest.config.js
@@ -0,0 +1,26 @@
+/*
+ * For a detailed explanation regarding each configuration property and type check, visit:
+ * https://jestjs.io/docs/configuration
+ */
+
+const merge = require('deepmerge');
+const path = require('path');
+
+const baseConfig = require('../../jest.config.packages');
+
+const displayName = path.basename(__dirname);
+
+module.exports = merge(baseConfig, {
+  // The display name when running multiple projects
+  displayName,
+
+  // An object that configures minimum threshold enforcement for coverage results
+  coverageThreshold: {
+    global: {
+      branches: 100,
+      functions: 100,
+      lines: 100,
+      statements: 100,
+    },
+  },
+});
diff --git a/packages/chain-controller/package.json b/packages/chain-controller/package.json
@@ -0,0 +1,71 @@
+{
+  "name": "@metamask/chain-controller",
+  "version": "0.0.0",
+  "description": "Manages chain-agnostic providers",
+  "keywords": [
+    "MetaMask",
+    "Ethereum"
+  ],
+  "homepage": "https://github.com/MetaMask/core/tree/main/packages/chain-controller#readme",
+  "bugs": {
+    "url": "https://github.com/MetaMask/core/issues"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/MetaMask/core.git"
+  },
+  "license": "MIT",
+  "sideEffects": false,
+  "exports": {
+    ".": {
+      "import": "./dist/index.mjs",
+      "require": "./dist/index.js",
+      "types": "./dist/types/index.d.ts"
+    },
+    "./package.json": "./package.json"
+  },
+  "main": "./dist/index.js",
+  "types": "./dist/types/index.d.ts",
+  "files": [
+    "dist/"
+  ],
+  "scripts": {
+    "build": "tsup --config ../../tsup.config.ts --tsconfig ./tsconfig.build.json --clean",
+    "build:docs": "typedoc",
+    "changelog:update": "../../scripts/update-changelog.sh @metamask/chain-controller",
+    "changelog:validate": "../../scripts/validate-changelog.sh @metamask/chain-controller",
+    "publish:preview": "yarn npm publish --tag preview",
+    "test": "jest --reporters=jest-silent-reporter",
+    "test:clean": "jest --clearCache",
+    "test:verbose": "jest --verbose",
+    "test:watch": "jest --watch"
+  },
+  "dependencies": {
+    "@metamask/base-controller": "^5.0.2",
+    "@metamask/chain-api": "^0.0.1",
+    "@metamask/keyring-api": "^6.1.1",
+    "@metamask/snaps-controllers": "^8.1.1",
+    "@metamask/snaps-sdk": "^4.2.0",
+    "@metamask/snaps-utils": "^7.4.0",
+    "@metamask/utils": "^8.3.0",
+    "uuid": "^8.3.2"
+  },
+  "devDependencies": {
+    "@metamask/auto-changelog": "^3.4.4",
+    "@types/jest": "^27.4.1",
+    "@types/readable-stream": "^2.3.0",
+    "deepmerge": "^4.2.2",
+    "jest": "^27.5.1",
+    "ts-jest": "^27.1.4",
+    "typedoc": "^0.24.8",
+    "typedoc-plugin-missing-exports": "^2.0.0",
+    "typescript": "~4.9.5"
+  },
+  "engines": {
+    "node": ">=16.0.0"
+  },
+  "publishConfig": {
+    "access": "public",
+    "registry": "https://registry.npmjs.org/"
+  }
+}