Using Autofix's .remove to remove an object property results in invalid code

Tell us about your environment

• ESLint Version: 4.10.0
• Node Version: 9.0.0
• npm Version: 5.5.1

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

Please show your full configuration:

Configuration

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

export default {
  meta: {
    fixable: "code"
  },
  create(context) {
    return {
      Property(node) {
        if (node.key.name === "b") {
          context.report({
            node,
            message: "Remove b",
            fix(fixer) {
              return fixer.remove(node);
            }
          });
        }
      }
    };
  }
};

Running --fixwith this rule on the following code:

const hey = {
 a: 'a',
 b: 'b',
 c: 'c'
}

eslint --fix

What did you expect to happen? It produces:

const hey = {
 a: 'a',
 c: 'c'
}

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

const hey = {
 a: 'a',
 ,
 c: 'c'
}

[mysticatea]

Oh, sorry, the 2nd example does not regard the case multiple properties exist on the same line…

module.exports = {
    meta: {
        fixable: "code"
    },
    create(context) {
        const sourceCode = context.getSourceCode()

        return {
            Property(node) {
                if (node.key.name === "b") {
                    context.report({
                        node,
                        message: "Remove b",
                        fix(fixer) {
                            let prevToken = sourceCode.getTokenBefore(node)
                            while (prevToken.value !== "," && prevToken.value !== "{") {
                                prevToken = sourceCode.getTokenBefore(node)
                            }
                            let lastToken = sourceCode.getTokenAfter(node)
                            if (lastToken.value !== ",") {
                                lastToken = sourceCode.getTokenBefore(lastToken)
                            }

                            const startLine = node.loc.start.line
                            const endLine = node.loc.end.line
                            return fixer.removeRange([prevToken.range[1], lastToken.range[1]])
                        }
                    });
                }
            }
        };
    }
};

[mysticatea]

It needs to handle tokens around the property with SourceCode object.

module.exports = {
    meta: {
        fixable: "code"
    },
    create(context) {
        const sourceCode = context.getSourceCode()

        return {
            Property(node) {
                if (node.key.name === "b") {
                    context.report({
                        node,
                        message: "Remove b",
                        * fix(fixer) {
                            yield fixer.remove(node);

                            const comma = sourceCode.getTokenAfter(node)
                            if (comma.value === ",") {
                                yield fixer.remove(comma)
                            }
                        }
                    });
                }
            }
        };
    }
};

But whitespaces are not token, so this code does not remove whitespaces. If you remove whitespaces as well, you have to use fixer.removeRange() method.

module.exports = {
    meta: {
        fixable: "code"
    },
    create(context) {
        const sourceCode = context.getSourceCode()

        return {
            Property(node) {
                if (node.key.name === "b") {
                    context.report({
                        node,
                        message: "Remove b",
                        fix(fixer) {
                            const startLine = node.loc.start.line
                            const endLine = node.loc.end.line
                            return fixer.removeRange([
                                sourceCode.getIndexFromLoc({ line: startLine, column: 0 }),
                                sourceCode.getIndexFromLoc({ line: endLine + 1, column: 0 })
                            ])
                        }
                    });
                }
            }
        };
    }
};