tools: enable additional eslint rules

Enable additional rules that node either already adheres to
or it makes sense to do so going forward: for-direction,
accessor-pairs, no-lonely-if and symbol-description.

Refs: https://eslint.org/docs/rules/for-direction
Refs: https://eslint.org/docs/rules/accessor-pairs
Refs: https://eslint.org/docs/rules/no-lonely-if
Refs: https://eslint.org/docs/rules/symbol-description

.eslintrc.yaml

@@ -18,6 +18,7 @@ overrides:
 rules:
   # Possible Errors
   # http://eslint.org/docs/rules/#possible-errors
+  for-direction: error
   no-control-regex: error
   no-debugger: error
   no-dupe-args: error
@@ -41,6 +42,7 @@ rules:
 
   # Best Practices
   # http://eslint.org/docs/rules/#best-practices
+  accessor-pairs: error
   dot-location: [error, property]
   eqeqeq: [error, smart]
   no-fallthrough: error
@@ -122,6 +124,7 @@ rules:
                 ignoreUrls: true,
                 tabWidth: 2}]
   new-parens: error
+  no-lonely-if: error
   no-mixed-spaces-and-tabs: error
   no-multiple-empty-lines: [error, {max: 2, maxEOF: 0, maxBOF: 0}]
   no-restricted-syntax: [error, {
@@ -172,6 +175,7 @@ rules:
   no-this-before-super: error
   prefer-const: [error, {ignoreReadBeforeAssign: true}]
   rest-spread-spacing: error
+  symbol-description: error
   template-curly-spacing: error
 
   # Custom rules in tools/eslint-rules

doc/.eslintrc.yaml

@@ -6,6 +6,7 @@ rules:
   no-undef: off
   no-unused-vars: off
   strict: off
+  symbol-description: off
 
   # add new ECMAScript features gradually
   no-var: error

test/.eslintrc.yaml

@@ -5,6 +5,7 @@ rules:
   # http://eslint.org/docs/rules/#ecmascript-6
   no-var: error
   prefer-const: error
+  symbol-description: off
 
   # Custom rules in tools/eslint-rules
   prefer-assert-iferror: error