first step for CI + Yarn update

.depcheckrc.json

@@ -0,0 +1,12 @@
+{
+  "ignores": [
+    "@lavamoat/allow-scripts",
+    "@lavamoat/preinstall-always-fail",
+    "@metamask/auto-changelog",
+    "@types/*",
+    "@yarnpkg/types",
+    "prettier-plugin-packagejson",
+    "ts-node",
+    "typedoc"
+  ]
+}

.eslintrc.js

@@ -0,0 +1,88 @@
+module.exports = {
+  root: true,
+
+  extends: ['@metamask/eslint-config'],
+
+  overrides: [
+    {
+      files: ['*.ts'],
+      extends: ['@metamask/eslint-config-typescript'],
+    },
+
+    {
+      files: ['*.js'],
+      parserOptions: {
+        sourceType: 'script',
+      },
+      extends: ['@metamask/eslint-config-nodejs'],
+    },
+
+    {
+      files: ['yarn.config.cjs'],
+      parserOptions: {
+        sourceType: 'script',
+        ecmaVersion: 2020,
+      },
+      settings: {
+        jsdoc: {
+          mode: 'typescript',
+        },
+      },
+      extends: ['@metamask/eslint-config-nodejs'],
+    },
+
+    {
+      files: ['*.test.ts', '*.test.js'],
+      extends: [
+        '@metamask/eslint-config-jest',
+        '@metamask/eslint-config-nodejs',
+      ],
+    },
+    {
+      files: ['src/SwapsController.ts'],
+      rules: {
+        'accessor-pairs': 'off',
+        'consistent-return': 'off',
+        'no-async-promise-executor': 'off',
+        '@typescript-eslint/prefer-optional-chain': 'off',
+        'no-restricted-syntax': 'off',
+        'import/no-named-as-default': 'off',
+      },
+    },
+    {
+      files: ['src/SwapsController.test.ts'],
+      rules: {
+        'no-new': 'off',
+      },
+    },
+    {
+      files: ['src/swapsInterfaces.ts'],
+      rules: {
+        '@typescript-eslint/naming-convention': 'off',
+      },
+    },
+    {
+      files: ['src/swapsUtil.ts'],
+      rules: {
+        'consistent-return': 'off',
+        'no-negated-condition': 'off',
+        '@typescript-eslint/naming-convention': 'off',
+      },
+    },
+    {
+      files: ['src/swapsUtil.test.ts'],
+      rules: {
+        'jest/require-to-throw-message': 'off',
+        '@typescript-eslint/naming-convention': 'off',
+        'no-restricted-globals': 'off',
+      },
+    },
+  ],
+  ignorePatterns: [
+    '!.eslintrc.js',
+    '!.prettierrc.js',
+    'dist/',
+    'docs/',
+    '.yarn/',
+  ],
+};

.gitattributes

@@ -1,3 +1,8 @@
 * text=auto
 
 yarn.lock linguist-generated=false
+
+# yarn v3
+# See: https://yarnpkg.com/getting-started/qa#which-files-should-be-gitignored
+/.yarn/releases/** binary
+/.yarn/plugins/** binary