no-dupe-keys: false negative between a normal property and a getter.

[mysticatea]

What version of ESLint are you using?

• 3.2.0

What parser (default, Babel-ESLint, etc.) are you using?

• default

Please show your full configuration:

• nothing

What did you do? Please include the actual source code causing the issue.

$ echo "var obj = {a:1, get a() { return 1 }}" | eslint --stdin --rule no-dupe-keys:2 --env es6 --no-eslintrc

What did you expect to happen?

• Duplicate key 'a'. (no-dupe-keys)

What actually happened? Please include the actual, raw output from ESLint.

• No errors.

[btmills]

This is interesting:

$ git log --oneline -n 1
5d063f2 Docs: Add plugin example to disabling with comments guide (fixes #6742)

$ rm -rf node_modules && npm install
# ...

$ echo "var obj = {a:1, get a() { return 1 }}" | bin/eslint.js --stdin --rule no-dupe-keys:2 --env es6 --no-eslintrc

But if I remove --env es6:

$ echo "var obj = {a:1, get a() { return 1 }}" | bin/eslint.js --stdin --rule no-dupe-keys:2 --no-eslintrc

<text>
  1:21  error  Parsing error: Redefinition of property

✖ 1 problem (1 error, 0 warnings)

[platinumazure]

@btmills --env es6 both enables an environment and changes a parserOptions property (ecmaVersion: 6). Can you please use --parserOptions ecmaVersion:6 in your tests to help isolate env vs parserOptions?

[btmills]

Good call, @platinumazure. I get no errors:

$ echo "var obj = {a:1, get a() { return 1 }}" | bin/eslint.js --stdin --rule no-dupe-keys:2 --parser-options ecmaVersion:6 --no-eslintrc

[mysticatea]

Yes. Duplicate properties were a kind of syntax errors until ES5. But ES6 relaxed this restriction due to computed properties.