Modernizes linting for typescript

linters/.eslintrc.typescript.js

@@ -0,0 +1,97 @@
+module.exports = {
+  extends: [
+    'plugin:@typescript-eslint/eslint-recommended',
+  ],
+  parser: '@typescript-eslint/parser',
+  plugins: [
+    '@typescript-eslint',
+  ],
+  settings: {
+    // Load <rootdir>/tsconfig.json to eslint
+    // https://github.com/import-js/eslint-plugin-import/issues/1485#issuecomment-571597574
+    'import/resolver': {
+      typescript: {},
+    },
+  },
+  rules: {
+
+    // Add .ts and .tsx to Airbnb's import/extensions config
+    'import/extensions': [
+      'error',
+      'ignorePackages',
+      {
+        js: 'never',
+        mjs: 'never',
+        jsx: 'never',
+        ts: 'never',
+        tsx: 'never',
+      },
+    ],
+
+    // Rules that exist in vanilla eslint but have typescript-specific replacements
+    'no-shadow': 0,
+    '@typescript-eslint/no-shadow': 2,
+
+    'no-unused-vars': 0,
+    '@typescript-eslint/no-unused-vars': 2,
+
+    'no-use-before-define': 0,
+    '@typescript-eslint/no-use-before-define': 2,
+
+    semi: 0,
+    '@typescript-eslint/semi': [2, 'always'],
+
+    // Rules to guard against potentially dangerous or confusing practices
+    '@typescript-eslint/no-explicit-any': 2,
+    '@typescript-eslint/ban-types': 2,
+
+    // Rules to enforce consistent formatting
+    '@typescript-eslint/type-annotation-spacing': 2,
+    '@typescript-eslint/member-delimiter-style': [2, {
+      multiline: {
+        delimiter: 'comma',
+        requireLast: true,
+      },
+      singleline: {
+        delimiter: 'comma',
+        requireLast: false,
+      },
+    }],
+    '@typescript-eslint/consistent-type-assertions': 2,
+    '@typescript-eslint/naming-convention': [
+      2,
+      {
+        selector: 'interface',
+        format: ['PascalCase'],
+        custom: {
+          // Prefixing interfaces with `I` is widely considered a form of Hungarian notation
+          // and is generally avoided. https://stackoverflow.com/a/41967120
+          regex: '^I[A-Z]',
+          match: false,
+        },
+      },
+    ],
+
+    // These rules can be turned off because typescript already checks for them
+    // https://github.com/typescript-eslint/typescript-eslint/blob/master/docs/getting-started/linting/FAQ.md#eslint-plugin-import
+    'import/named': 0,
+    'import/namespace': 0,
+    'import/default': 0,
+    'import/no-named-as-default-member': 0,
+
+    // These rules can be computationally expensive. If linting is becoming slow, consider
+    // moving them to a separate script or tweaking their settings.
+    // https://github.com/typescript-eslint/typescript-eslint/blob/master/docs/getting-started/linting/FAQ.md#eslint-plugin-import
+    'import/no-named-as-default': 2,
+    'import/no-cycle': [
+      2,
+      {
+        maxDepth: '∞',
+
+        // If you don't need cycle detection to expand to external modules,
+        // override this to true to speed up linting.
+        ignoreExternal: false,
+      },
+    ],
+  },
+};