extend plugins + write tests for plugin api

.vscode/settings.json

@@ -1,7 +1,9 @@
 {
   "deno.enable": true,
+  "deno.cacheOnSave": true,
+  "deno.lint": true,
   "[typescript]": {
     "editor.defaultFormatter": "denoland.vscode-deno"
   },
   "editor.formatOnSave": true
-}
+}

spektr.ts

@@ -46,12 +46,16 @@ export class CLI {
       }
       & ParseArgsConfig = {},
   ) {
-    const { name, prefix, plugins, helpFn, ...parseOptions } = opts
+    const { name, prefix, helpFn, ...parseOptions } = opts
     this.name = name
     this.prefix = prefix
     this.#parseOptions = parseOptions
     this.helpFn = helpFn
 
+    const plugins = this.parent
+      ? [...this.parent.plugins, ...(opts.plugins || [])]
+      : opts.plugins
+
     if (plugins) {
       this.plugins = plugins
       for (const plugin of plugins) {

spektr_test.ts

@@ -11,7 +11,7 @@ import {
   spy,
 } from 'https://deno.land/[email protected]/testing/mock.ts'
 import { CLI } from './spektr.ts'
-import { Positionals } from './types.ts'
+import { Plugin, Positionals } from './types.ts'
 import { ParsedOptions } from './types.ts'
 
 describe('CLI', () => {
@@ -318,4 +318,36 @@ describe('CLI', () => {
       assertSpyCall(mwSpy, 0)
     })
   })
+  describe('plugins', () => {
+    it('should apply them', () => {
+      const helpFnSpy = spy(() => `Plugin`)
+      const myPlugin: Plugin = () => ({
+        helpFn: () => 'Help',
+        helpMessage: helpFnSpy,
+      })
+
+      const cli = new CLI({ plugins: [myPlugin] })
+      cli.help()
+
+      cli.handle(['--help'])
+
+      assertSpyCall(helpFnSpy, 0)
+    })
+    it('should nest plugins', () => {
+      const helpFnSpy = spy(() => `Plugin`)
+      const myPlugin: Plugin = () => ({
+        helpFn: () => 'Help',
+        helpMessage: helpFnSpy,
+      })
+
+      const cli = new CLI({ plugins: [myPlugin] })
+      cli.help()
+
+      cli.program('sub').help()
+
+      cli.handle(['sub', '--help'])
+
+      assertSpyCall(helpFnSpy, 0)
+    })
+  })
 })