README.md

gatsby-plugin-utils

Usage

npm install gatsby-plugin-utils

validateOptionsSchema

The validateOptionsSchema function verifies that the proper data types of options were passed into a plugin from the gatsby-config.js file. It is called internally by Gatsby to validate each plugin's options when a site is started.

Example

import { validateOptionsSchema } from "gatsby-plugin-utils"

await validateOptionsSchema(pluginName, pluginSchema, pluginOptions)

testPluginOptionsSchema

Utility to validate and test plugin options schemas. An example of a plugin options schema implementation can be found in the gatsby-node.js file of gatsby-plugin-google-analytics.

Example

// This is an example using Jest (https://jestjs.io/)
import { testPluginOptionsSchema } from "gatsby-plugin-utils"

it(`should partially validate one value of a schema`, async () => {
  const pluginSchema = ({ Joi }) =>
    Joi.object({
      someOtherValue: Joi.string(),
      toVerify: Joi.boolean(),
    })

  // Only the "toVerify" key of the schema will be verified in this test
  const { isValid, errors } = await testPluginOptionsSchema(pluginSchema, {
    toVerify: `abcd`,
  })

  expect(isValid).toBe(false)
  expect(errors).toEqual([`"toVerify" must be a boolean`])
})

isGatsbyNodeLifecycleSupported

Utility to be used by plugins to do runtime check against gatsby core package checking wether particular gatsby-node lifecycle API is supported. Useful for plugins to be able to support multiple gatsby core versions.

Example

const { isGatsbyNodeLifecycleSupported } = require(`gatsby-plugin-utils`)

// only use createSchemaCustomization lifecycle only when it's available.
if (isGatsbyNodeLifecycleSupported(`createSchemaCustomization`)) {
  exports.createSchemaCustomization = function createSchemaCustomization({
    actions,
  }) {
    // customize schema
  }
}

hasFeature

Feature detection is now part of Gatsby. As a plugin author you don't know what version of Gatsby a user is using. hasFeature allows you to check if the current version of Gatsby has a certain feature.

Here's a list of features: // TODO

Example

const { hasFeature } = require(`gatsby-plugin-utils`)

if (!hasFeature(`image-cdn`)) {
  // You can polyfill image-cdn here so older versions have support as well
}