const path = require('path')
const yaml = require('js-yaml')
/**
* Helpers for extracting information from the webhook event, which can be
* passed to GitHub API calls.
*
* @property {github} github - An authenticated GitHub API client
* @property {payload} payload - The webhook event payload
* @property {logger} log - A logger
*/
class Context {
constructor (event, github, log) {
Object.assign(this, event)
this.github = github
this.log = log
}
/**
* Return the `owner` and `repo` params for making API requests against a
* repository.
*
* @param {object} [object] - Params to be merged with the repo params.
*
* @example
*
* const params = context.repo({path: '.github/config.yml'})
* // Returns: {owner: 'username', repo: 'reponame', path: '.github/config.yml'}
*
*/
repo (object) {
const repo = this.payload.repository
return Object.assign({
owner: repo.owner.login || repo.owner.name,
repo: repo.name
}, object)
}
/**
* Return the `owner`, `repo`, and `number` params for making API requests
* against an issue or pull request. The object passed in will be merged with
* the repo params.
*
* @example
*
* const params = context.issue({body: 'Hello World!'})
* // Returns: {owner: 'username', repo: 'reponame', number: 123, body: 'Hello World!'}
*
* @param {object} [object] - Params to be merged with the issue params.
*/
issue (object) {
const payload = this.payload
return Object.assign({
number: (payload.issue || payload.pull_request || payload).number
}, this.repo(), object)
}
/**
* Returns a boolean if the actor on the event was a bot.
* @type {boolean}
*/
get isBot () {
return this.payload.sender.type === 'Bot'
}
/**
* Reads the app configuration from the given YAML file in the `.github`
* directory of the repository.
*
* @example <caption>Contents of <code>.github/config.yml</code>.</caption>
*
* close: true
* comment: Check the specs on the rotary girder.
*
* @example <caption>App that reads from <code>.github/config.yml</code>.</caption>
*
* // Load config from .github/config.yml in the repository
* const config = await context.config('config.yml')
*
* if (config.close) {
* context.github.issues.comment(context.issue({body: config.comment}))
* context.github.issues.edit(context.issue({state: 'closed'}))
* }
*
* @example <caption>Using a <code>defaultConfig</code> object.</caption>
*
* // Load config from .github/config.yml in the repository and combine with default config
* const config = await context.config('config.yml', {comment: 'Make sure to check all the specs.'})
*
* if (config.close) {
* context.github.issues.comment(context.issue({body: config.comment}));
* context.github.issues.edit(context.issue({state: 'closed'}))
* }
*
* @param {string} fileName - Name of the YAML file in the `.github` directory
* @param {object} [defaultConfig] - An object of default config options
* @return {Promise<Object>} - Configuration object read from the file
*/
async config (fileName, defaultConfig) {
const params = this.repo({path: path.posix.join('.github', fileName)})
try {
const res = await this.github.repos.getContent(params)
const config = yaml.safeLoad(Buffer.from(res.data.content, 'base64').toString()) || {}
return Object.assign({}, defaultConfig, config)
} catch (err) {
if (err.code === 404) {
if (defaultConfig) {
return defaultConfig
}
return null
} else {
throw err
}
}
}
}
module.exports = Context