fix: update to latest ESLint 7.x.x

- two new rules
- new options for a few rules
- moved one set of tests off of the deprecated CLIEngine class

https://eslint.org/blog/

index.js

@@ -110,6 +110,10 @@ module.exports = {
     'no-unreachable-loop': 'error',
     'no-unsafe-finally': 'error',
     'no-unsafe-negation': ['error', { enforceForOrderingRelations: true }],
+    'no-unsafe-optional-chaining': [
+      'error',
+      { disallowArithmeticOperators: true },
+    ],
     'no-useless-backreference': 'error',
     'use-isnan': 'error',
     // https://github.com/eslint/eslint/issues/11899
@@ -149,7 +153,15 @@ module.exports = {
     'no-fallthrough': 'error',
     'no-floating-decimal': PRETTIER,
     'no-global-assign': 'error',
-    'no-implicit-coercion': 'error',
+    'no-implicit-coercion': [
+      'error',
+      {
+        boolean: true,
+        number: true,
+        string: true,
+        disallowTemplateShorthand: true,
+      },
+    ],
     'no-implicit-globals': 'error',
     'no-implied-eval': 'error',
     'no-invalid-this': 'error',
@@ -163,6 +175,7 @@ module.exports = {
     'no-new': 'error',
     'no-new-func': 'error',
     'no-new-wrappers': 'error',
+    'no-nonoctal-decimal-escape': 'error',
     'no-octal': 'error',
     'no-octal-escape': 'error',
     'no-param-reassign': 'off',
@@ -175,7 +188,7 @@ module.exports = {
     'no-script-url': 'error',
     'no-self-assign': 'error',
     'no-self-compare': 'error',
-    'no-sequences': 'error',
+    'no-sequences': ['error', { allowInParentheses: true }],
     'no-throw-literal': 'error',
     'no-unmodified-loop-condition': 'error',
     'no-unused-expressions': 'error',
@@ -279,7 +292,7 @@ module.exports = {
     'no-lonely-if': 'error',
     'no-mixed-operators': 'error',
     'no-mixed-spaces-and-tabs': PRETTIER,
-    'no-multi-assign': 'error',
+    'no-multi-assign': ['error', { ignoreNonDeclaration: false }],
     'no-multiple-empty-lines': PRETTIER,
     'no-negated-condition': 'off',
     'no-nested-ternary': 'error',