chore: consolidate eslint config (#627)

This change:

- Removes all `.eslintignore` , `.eslintrc` files or `package.json`-embedded config and replaces it with a single root `.eslintrc.js`
- Removes all lint-related scripts from all workspaces (including `depcheck`)
- Removes all dev deps on `eslint` and its ilk (and `ava`, since it will come from the workspace root)
- Upgrade `eslint`, `eslint-plugin-ava`, as well as other plugins used by specific packages; moves them all to workspace root
- Removes unused/deprecated `eslint-plugin-node` in lieu of `eslint-plugin-n`
- Adds a prettier config (in case someone wants to use it; I'd like to add it to our workflow later)

I note that ESLint seemed to be misconfigured before this change; none of the rules specified in the root config were being checked.  This means that there are a whole lot of lint fixes that need to be made.

To lint, run `yarn lint` as before (which will also run `depcheck`) from the workspace root.  Likewise, `lint:fix` runs a fix, and `lint:depcheck` will use lerna to run `lint:depcheck` wherever it is defined.

chore: remove @metamask/eslint-config-nodejs (#639)

Closes #637

This removes the dep on `@metamask/eslint-config-nodejs` which has a peer dep on `@metamask/eslint-config`.  `npm` will automatically install that module, and that module _itself_ has peer deps which may also conflict with our deps currently or in the future.

Given `@metamask/eslint-config-nodejs` is _intended_ to be used with `@metamask/eslint-config`, we then must drop it.

The ESLint config has been modified to extend both `eslint/recommended` and `eslint-plugin-n/recommended` configs.  Extra rules were copied from `@metamask/eslint-config-nodejs`, but many (such as restrictions on browser-only globals) were not, since these can be trivially addressed by ESLint's `env` configuration (unsure what they are doing where this is a problem).  Since this surfaced a whole lot of new issues--especially in test code and templates--additional overrides were necessary.  Any rules which were removed from the main `rules` prop were likely already enabled in `eslint/recommended`.

chore: lint everything

.eslintrc.js

@@ -0,0 +1,177 @@
+module.exports = {
+  root: true,
+  // this is the same as an .eslintignore file
+  ignorePatterns: [
+    '.yarn/**/*',
+    '**/*.umd.js',
+    '**/node_modules/**/*',
+    'docs/**/*',
+    'packages/*/examples/**/*',
+    'packages/*/test/**/fixtures/**/*',
+    'packages/*/test/projects/**/*',
+    'packages/lavapack/bundle.js',
+    'packages/lavapack/src/runtime-cjs.js',
+    'packages/lavapack/src/runtime.js',
+    'packages/perf/trials/**/*',
+    'packages/survey/mitm/**/*',
+    'packages/viz/dist/**/*',
+    'packages/viz/src/example-policies/**/*',
+  ],
+  parserOptions: {
+    // this should be whatever the latest env version provides. some plugin is
+    // messing with this, so we need to set it manually.
+    // https://eslint.org/docs/latest/use/configure/language-options#specifying-environments
+    ecmaVersion: 12,
+  },
+  env: { es2020: true, node: true }, // this should be synced with the version of V8 used by the min supported node version
+  extends: ['eslint:recommended', 'plugin:n/recommended'],
+  rules: {
+    // base rules; none of these are in eslint/recommended
+    'arrow-spacing': ['error', { before: true, after: true }],
+    'brace-style': ['error', '1tbs'],
+    'comma-dangle': ['error', 'always-multiline'],
+    curly: ['error', 'all'],
+    'eol-last': ['error', 'always'],
+    indent: ['error', 2, { SwitchCase: 1, ObjectExpression: 'first' }],
+    'no-empty': ['error', { allowEmptyCatch: true }],
+    quotes: ['error', 'single'],
+    semi: ['error', 'never'],
+    'space-before-blocks': ['error', 'always'],
+    'space-before-function-paren': [
+      'error',
+      {
+        anonymous: 'ignore',
+        named: 'ignore',
+        asyncArrow: 'always',
+      },
+    ],
+
+    // additional errors not in n/recommended
+    'n/callback-return': 'error',
+    'n/handle-callback-err': 'error',
+    'n/no-callback-literal': 'error',
+    'n/no-mixed-requires': 'error',
+    'n/no-new-require': 'error',
+    'n/no-restricted-import': 'error',
+    'n/no-restricted-require': 'error',
+    'n/prefer-global/buffer': 'error',
+    'n/prefer-global/console': 'error',
+    'n/prefer-global/process': 'error',
+    'n/prefer-global/text-decoder': 'error',
+    'n/prefer-global/text-encoder': 'error',
+    'n/prefer-global/url-search-params': 'error',
+    'n/prefer-global/url': 'error',
+    'n/prefer-promises/dns': 'error',
+    'n/prefer-promises/fs': 'error',
+
+    // these rules seem broken in a monorepo
+    'n/no-extraneous-require': 'off',
+    'n/no-unpublished-require': 'off',
+
+    // we should probably actually fix these three and turn these back on
+    'n/no-sync': 'off', // very few reasons to actually use this; "CLI tool" is not one of them
+    'n/no-process-exit': 'off', // should not be used with async code
+  },
+  // these are plugin-specific settings.
+  settings: {
+    // note that this name is "node" while the plugin is named "n".
+    // probably for historical reasons, but this may eventually break.
+    node: {
+      version: '14.17.0', // should be set to minimum node version supported
+      allowModules: ['deep-equal'], // something weird about this dependency
+    },
+    react: {
+      version: 'detect',
+    },
+  },
+  overrides: [
+    {
+      files: ['packages/*/test/**/*.js', 'packages/*/src/**/*.test.js'],
+      extends: ['plugin:ava/recommended'],
+      rules: {
+        'ava/no-import-test-files': 'off',
+      },
+    },
+    {
+      files: ['packages/core/src/**/*.js'],
+      globals: {
+        Compartment: 'readonly',
+        templateRequire: 'readonly',
+        lockdown: 'readonly',
+      },
+    },
+    {
+      files: ['packages/*/test/**/*.js'],
+      env: {
+        browser: true,
+      },
+      rules: {
+        'no-unused-vars': 'off',
+        'no-undef': 'off',
+        'n/no-path-concat': 'off', // this should be removed and the issues fixed
+        'n/no-missing-require': 'off',
+      },
+    },
+    {
+      files: ['packages/core/lib/**/*.js'],
+      rules: {
+        'no-unused-vars': 'off',
+      },
+    },
+    {
+      files: ['packages/lavapack/src/*-template.js'],
+      globals: {
+        templateRequire: 'readonly',
+        self: 'readonly',
+        __reportStatsHook__: 'readonly',
+        __createKernel__: 'readonly',
+      },
+    },
+    {
+      files: ['packages/core/src/*Template.js'],
+      globals: {
+        __lavamoatDebugOptions__: 'readonly',
+        __lavamoatSecurityOptions__: 'readonly',
+        self: 'readonly',
+        __createKernelCore__: 'readonly',
+      },
+    },
+    {
+      files: ['packages/perf/**/*.js'],
+      globals: {
+        lockdown: 'readonly',
+        Compartment: 'readonly',
+      },
+    },
+    {
+      // for viz package.  most of this copied out of its own eslint config
+      files: ['packages/viz/**/*.js'],
+      env: {
+        browser: true,
+        es2020: true,
+      },
+      parserOptions: {
+        ecmaFeatures: {
+          jsx: true,
+        },
+        sourceType: 'module',
+      },
+      extends: ['plugin:react/recommended'],
+      plugins: ['react', 'import'],
+      rules: {
+        'no-negated-condition': 'off',
+        'import/extensions': ['error', 'always', { ignorePackages: true }],
+        'import/no-unassigned-import': 'off',
+        'import/unambiguous': 'off',
+        'react/prop-types': 'off',
+        'n/no-missing-import': 'off',
+      },
+    },
+    {
+      files: ['packages/viz/src/App.test.js'],
+      env: {
+        mocha: true,
+      },
+    },
+  ],
+}

commitlint.config.js

@@ -8,4 +8,4 @@ module.exports = {
     'subject-case': [0],
     'subject-full-stop': [0],
   },
-};
+}