feat: add hook context

src/errors.ts

@@ -0,0 +1,23 @@
+export class ExitError extends Error {
+  'cli-ux': {
+    exit: number
+  }
+  code?: string
+
+  constructor(error?: string | Error | number, exitCode = 0) {
+    if (typeof error === 'number') {
+      exitCode = error
+      error = undefined
+    }
+    const addCode = (error: ExitError) => {
+      error['cli-ux'] = error['cli-ux'] || {}
+      error['cli-ux'].exit = exitCode
+      return error
+    }
+    if (error instanceof Error) {
+      return addCode(error as any)
+    }
+    super(error || `${exitCode}: ${status}`)
+    this.code = 'EEXIT'
+  }
+}

src/hooks.ts

@@ -17,4 +17,12 @@ export interface Hooks {
   }
 }
 
-export type Hook<K extends keyof Hooks> = (options: Hooks[K] & {config: Config.IConfig}) => any
+export type Hook<K extends keyof Hooks> = (this: Hook.Context, options: Hooks[K] & {config: Config.IConfig}) => any
+
+export namespace Hook {
+  export interface Context {
+    exit(code?: number): void
+    error(message: string | Error, options?: {exit?: number}): void
+    log(message?: any): void
+  }
+}

src/plugin.ts

@@ -4,7 +4,8 @@ import {inspect} from 'util'
 
 import {Command} from './command'
 import Debug from './debug'
-import {Hooks} from './hooks'
+import {ExitError} from './errors'
+import {Hook, Hooks} from './hooks'
 import {Manifest} from './manifest'
 import {PJSON} from './pjson'
 import {Topic} from './topic'
@@ -190,18 +191,29 @@ export class Plugin implements IPlugin {
   }
 
   async runHook<T extends Hooks, K extends keyof T>(event: K, opts: T[K]) {
+    const context: Hook.Context = {
+      exit(code) {
+        throw new ExitError(code)
+      },
+      log(message) {
+        process.stdout.write((message || '') + '\n')
+      },
+      error(message, options = {}) {
+        throw new ExitError(message, options.exit)
+      },
+    }
     const promises = (this.hooks[event] || [])
     .map(async hook => {
       try {
         const p = tsPath(this.root, hook)
         debug('hook', event, p)
-        const search = (m: any) => {
+        const search = (m: any): Hook<K> => {
           if (typeof m === 'function') return m
           if (m.default && typeof m.default === 'function') return m.default
-          return Object.values(m).find((m: any) => typeof m === 'function')
+          return Object.values(m).find((m: any) => typeof m === 'function') as Hook<K>
         }
 
-        await search(require(p))(opts)
+        await search(require(p)).call(context, opts)
       } catch (err) {
         if (err && err['cli-ux'] && err['cli-ux'].exit !== undefined) throw err
         process.emitWarning(err)