From 059461af748f4a3ca6948549ccf0c5d5b4190a37 Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Sat, 30 Jan 2021 19:02:00 +0100
Subject: [PATCH] fix: stop and restart repl to allow enquirer prompt (#188)

---
 jest.config.js        |  2 +-
 src/command.ts        |  6 +++---
 src/program.ts        |  3 +--
 src/prompter.ts       |  2 +-
 src/repl.ts           | 25 ++++++++++++++++++++++---
 tests/program.spec.ts | 35 ++++++++++++++++++++++++++++++++++-
 6 files changed, 62 insertions(+), 11 deletions(-)

diff --git a/jest.config.js b/jest.config.js
index 88972cb3..20febba0 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -8,7 +8,7 @@ module.exports = {
   testMatch: ['**/*.spec.ts'],
   globals: {
     'ts-jest': {
-      tsConfig: 'tsconfig.json'
+      tsconfig: 'tsconfig.json'
     }
   },
   setupFiles: ['./jest.setup.js']
diff --git a/src/command.ts b/src/command.ts
index d61cbbcb..b266aabc 100644
--- a/src/command.ts
+++ b/src/command.ts
@@ -1,7 +1,7 @@
-import { Argv, CommandModule, Arguments as BaseArguments } from 'yargs'
+import { Arguments as BaseArguments, Argv, CommandModule } from 'yargs'
 import { Argument, ArgumentOptions } from './argument'
-import { Option, OptionOptions } from './option'
 import { InferArgType } from './baseArg'
+import { Option, OptionOptions } from './option'
 import { prompter } from './prompter'
 
 export type Arguments<T = {}> = T &
@@ -279,7 +279,7 @@ export class Command<T = {}> {
           return this.handler(args, commandRunner)
         }
 
-        // Display help this command contains sub-commands
+        // Display help if this command contains sub-commands
         if (this.getCommands().length) {
           return commandRunner(`${this.getFqn()} --help`)
         }
diff --git a/src/program.ts b/src/program.ts
index f73f5cb1..06cf70d8 100644
--- a/src/program.ts
+++ b/src/program.ts
@@ -2,9 +2,8 @@ import { EventEmitter } from 'events'
 import TypedEventEmitter from 'typed-emitter'
 import { Argv } from 'yargs'
 import createYargs from 'yargs/yargs'
-import { Command, command } from './command'
+import { Arguments, Command, command } from './command'
 import { Repl, repl } from './repl'
-import { Arguments } from './command'
 import { isPromise } from './utils'
 
 interface Events {
diff --git a/src/prompter.ts b/src/prompter.ts
index 7e7ff5a4..90003b5b 100644
--- a/src/prompter.ts
+++ b/src/prompter.ts
@@ -18,7 +18,7 @@ type PromptType =
 type Question = any
 
 /**
- * Creates a new command, which can be added to a program.
+ * Creates a new prompter instance
  */
 export function prompter<T = {}>(baseArgs: Array<Argument | Option>, args: T) {
   return new Prompter(baseArgs, args)
diff --git a/src/repl.ts b/src/repl.ts
index 204f6420..f61b513e 100644
--- a/src/repl.ts
+++ b/src/repl.ts
@@ -1,9 +1,10 @@
-import nodeRepl, { REPLServer } from 'repl'
+import { Prompt } from 'enquirer'
 import { CompleterResult } from 'readline'
-import { Context } from 'vm'
+import nodeRepl, { REPLServer } from 'repl'
 import { parseArgsStringToArgv } from 'string-argv'
-import { Program } from './program'
+import { Context } from 'vm'
 import { autocompleter, Autocompleter } from './autocompleter'
+import { Program } from './program'
 
 const DEFAULT_PROMPT = '> '
 
@@ -27,6 +28,11 @@ export class Repl {
     private prompt: string = DEFAULT_PROMPT
   ) {
     this.autocompleter = autocompleter(program)
+
+    // Stop the server to avoid eval'ing stdin from prompts
+    this.program.on('run', () => {
+      this.stop()
+    })
   }
 
   /**
@@ -42,6 +48,14 @@ export class Repl {
       completer: this.completer.bind(this),
       ignoreUndefined: true,
     })
+
+    // Fixes bug with hidden cursor after enquirer prompt
+    // @ts-ignore
+    new Prompt().cursorShow()
+  }
+
+  public stop() {
+    this.server?.close()
   }
 
   /**
@@ -101,6 +115,11 @@ export class Repl {
       this.errorHandler(error)
     }
 
+    // Since we stop the server when a command is executed (by listening to the
+    // 'run' event in the constructor), we need to start a new instance when the
+    // command is finished.
+    this.start()
+
     // The result passed to this function is printed by the Node REPL server,
     // but we don't want to use that, so we pass undefined instead.
     cb(null, undefined)
diff --git a/tests/program.spec.ts b/tests/program.spec.ts
index fd3146c0..cdc26e8a 100644
--- a/tests/program.spec.ts
+++ b/tests/program.spec.ts
@@ -1,6 +1,33 @@
 // @ts-ignore
 import mockArgv from 'mock-argv'
-import { program, Program, command } from '../src'
+import { mocked } from 'ts-jest/utils'
+import { command, program, Program, Repl } from '../src'
+
+jest.mock('../src/repl', () => {
+  return {
+    repl: jest.fn().mockImplementation(() => {
+      return new MockedRepl()
+    }),
+    Repl: jest.fn().mockImplementation(() => {
+      return MockedRepl
+    }),
+  }
+})
+
+// Repl mock
+const replStartFn = jest.fn()
+const replPauseFn = jest.fn()
+const replResumeFn = jest.fn()
+class MockedRepl {
+  start = replStartFn
+  pause = replPauseFn
+  resume = replResumeFn
+}
+
+beforeEach(() => {
+  const MockedRepl = mocked(Repl, true)
+  MockedRepl.mockClear()
+})
 
 test('program should return new Program object', () => {
   expect(program()).toBeInstanceOf(Program)
@@ -25,3 +52,9 @@ test('program executes argv', async () => {
     await expect(app.run()).resolves.toBe('foo')
   })
 })
+
+test('program starts repl', async () => {
+  const app = program()
+  expect(app.repl()).toBeInstanceOf(MockedRepl)
+  expect(replStartFn).toHaveBeenCalled()
+})