API

seolint has three modules:

import * as seolint from "seolint";
import * as config from "seolint/config";
import * as presets from "seolint/presets";

`seolint`

`lint(html, config?, url?)`

Lints an HTML string. It resolves with a list of messages, or undefined when every rule passes. It does not run the site checks, because it sees one page.

let messages = await seolint.lint("<html>...</html>", {
  host: "https://example.com",
});

Give the page's url for the rules that compare against it, such as canonical.href.self.

`fs(path, config?)`

Lints a file, or every HTML file in a folder. A folder is a site root, so it also gets the site checks. It resolves with a report.

let report = await seolint.fs("public", await config.resolve());

`url(href, config?)`

Fetches and lints a URL. It resolves with a report. Its origin is the host, unless the config sets one.

`run(config?, argv?)`

Lints every config.inputs, relative to argv.cwd. This is what the CLI does.

let options = { cwd: process.cwd() };
let report = await seolint.run(await config.resolve(options), options);

lint(), fs(), url(), and run() run the built-in plugins, then config.plugins. They reject when a plugin throws, when an input cannot be read, or when the config names an unknown rule.

`seolint/config`

resolve(argv?) loads the config file from argv.cwd, and applies argv.host, argv.inputs, and argv.workers over it. It rejects for an invalid config.
define(config) types a config. See Configuration.
plugin(definition) types a plugin. See Plugins.
find(root, start) and load(root) find and load a config file.

`seolint/presets`

The built-in presets: strict, essentials, and staging.

Messages

Each problem is a message:

Field	Type	Description
`rule`	`string`	The rule name, such as `title.content.length`.
`severity`	`"error"` or `"warn"`	The severity from the config.
`message`	`string`	What is wrong.
`line`	`number`	The line of the element. Absent without an element.
`col`	`number`	The column of the element. Absent without an element.
`docs`	`string`	A link to the rule's page, when the rule has one.

Reports

fs(), url(), and run() resolve with a report. Each input with problems maps to its messages. Inputs with no problems are left out:

let report = await seolint.fs("public");
for (let [input, messages] of Object.entries(report)) {
  console.log(input, messages.length);
}

Types

seolint exports the types of the API, such as Config, Plugin, Message, Report, Severity, and Setting. seolint/config exports the types for configs and plugins, such as Config, Plugin, and Setting.