Support esm in .js

.eslintrc.yaml

@@ -10,6 +10,11 @@ env:
 parserOptions:
   ecmaVersion: 2017
 
+overrides:
+  - files: ["doc/api/esm.md", "*.mjs"]
+    parserOptions:
+      sourceType: module
+
 rules:
   # Possible Errors
   # http://eslint.org/docs/rules/#possible-errors

.gitignore

@@ -12,6 +12,7 @@
 !.gitignore
 !.gitkeep
 !.mailmap
+!.nycrc
 !.remarkrc
 
 core

.nycrc

@@ -0,0 +1,6 @@
+{
+  "exclude": [
+    "**/internal/process/write-coverage.js"
+  ],
+  "reporter": ["html", "text"]
+}