filter-rule.md

id	title
filter-rule	Creating Filter Rule

Filter rule is same writing convention with linting/fixing rule, but has different context.

Usage of filter rule

Add filter rule name to filters field.

{
  "filters": {
    "comments": true
  }
}

See configuring.md for details.

Filter rule name

{
  "filters": {
    "<name>": true
  }
}

The rule <name> can be accept following patterns:

• textlint-filter-rule-<name>
• <name>
• @scope/textlint-filter-rule-<name>
• @scope/<name>

FilterRuleContext

shouldIgnore() is core API of FilterRuleContext.

• shouldIgnore(range, { ruleId }) is a method that report reports ignoring range( is array like [start, end]).
  • context.shouldIgnore(node.range); filter all messages
  • context.shouldIgnore(node.range, { ruleId: "rule-id" }); filter messages that are reported "rule-id" rule.
• Syntax.* is const values of TxtNode type.
  • e.g.) context.Syntax.Str
  • packages/@textlint/ast-node-types/src/index.ts
• getSource(<node>) is a method gets the source code for the given node.
  • e.g.) context.getSource(node); // => "text"
• getFilePath() return file path that is linting target.
  • e.g.) context.getFilePath(): // => /path/to/file.md or undefined

Example

Filter all BlockQuote node.

module.exports = function (context) {
    const exports = {};
    exports[context.Syntax.BlockQuote] = function (node) {
        context.shouldIgnore(node.range);
        /* === 
        context.shouldIgnore(node.range, {
             ruleId: "*"
        });
        */
    };
    return exports;
};

Filter messages which is reported by no-todo rule.

module.exports = function (context) {
    const exports = {};
    exports[context.Syntax.Str] = function (node) {
        context.shouldIgnore(node.range, {
            ruleId: "no-todo"
        });
    };
    return exports;
};

Package name convention

textlint's filter rule should use textlint-filter-rule- prefix.

For example, filtering by comment rule is textlint-filter-rule-comments.

textlint user use it by setting following:

{
    "filters": {
        "comments": true
    }
}

Example rules:

• textlint-filter-rule-comments