feat: support prompt (#60)

README.md

@@ -94,6 +94,42 @@ The opposite assertion of `expect`.
 
 Write data to stdin, see example above.
 
+#### coffee.waitForPrompt(bool)
+
+If you set false, coffee will write stdin immediately, otherwise will wait for `prompt` message.
+
+```js
+coffee.fork('/path/to/cli', ['abcdefg'])
+.waitForPrompt()
+.write('tz\n')
+.write('2\n');
+.end(done);
+```
+
+cli process should emit `prompt` message:
+
+```js
+const readline = require('readline');
+
+const rl = readline.createInterface({
+  input: process.stdin,
+  output: process.stdout
+});
+
+function ask(q, callback) {
+  process.send({ type: 'prompt' });
+  rl.question(q, callback);
+}
+
+ask('What\'s your name? ', answer => {
+  console.log(`hi, ${answer}`);
+  ask('How many coffee do you want? ', answer => {
+    console.log(`here is your ${answer} coffee`);
+    rl.close();
+  });
+});
+```
+
 #### coffee.end(callback)
 
 Callback will be called after completing the assertion, the first argument is Error if throw exception.

lib/coffee.js

@@ -148,12 +148,20 @@ class Coffee extends EventEmitter {
     return this;
   }
 
-  /*
-    Write data to stdin of the command
-  */
-  write(value) {
+
+  /**
+   * Write data to stdin of the command
+   * @param {String} input - input text
+   * @return {Coffee} return self for chain
+   */
+  write(input) {
     assert(!this._isEndCalled, 'can\'t call write after end');
-    this.stdin.push(value);
+    this.stdin.push(input);
+    return this;
+  }
+
+  waitForPrompt(enable) {
+    this._isWaitForPrompt = enable !== false;
     return this;
   }
 
@@ -211,11 +219,23 @@ class Coffee extends EventEmitter {
     cmd.once('close', this.emit.bind(this, 'close'));
 
     if (this.stdin.length) {
-      this.stdin.forEach(function(buf) {
-        debug('input stdin `%s`', show(buf));
-        cmd.stdin.write(buf);
-      });
-      cmd.stdin.end();
+      if (this._isWaitForPrompt) {
+        // wait for message then write to stdin
+        cmd.on('message', msg => {
+          if (msg.type !== 'prompt' || this.stdin.length === 0) return;
+          const buf = this.stdin.shift();
+          debug('prompt stdin `%s`', show(buf));
+          cmd.stdin.write(buf);
+          if (this.stdin.length === 0) cmd.stdin.end();
+        });
+      } else {
+        // write immediately
+        this.stdin.forEach(function(buf) {
+          debug('input stdin `%s`', show(buf));
+          cmd.stdin.write(buf);
+        });
+        cmd.stdin.end();
+      }
     }
 
     return this;
@@ -240,6 +260,7 @@ class Coffee extends EventEmitter {
     };
     this.complete = false;
     this._isEndCalled = false;
+    this._isWaitForPrompt = false;
     this._debug_stdout = false;
     this._debug_stderr = false;
     this._isCoverage = true;

package.json

@@ -4,15 +4,15 @@
   "description": "Test command line on nodejs",
   "main": "index.js",
   "dependencies": {
-    "cross-spawn": "^5.1.0",
-    "debug": "^2.6.8"
+    "cross-spawn": "^6.0.5",
+    "debug": "^3.1.0"
   },
   "devDependencies": {
-    "autod": "^2.8.0",
-    "egg-ci": "^1.6.0",
+    "autod": "^3.0.1",
+    "egg-ci": "^1.8.0",
     "eslint": "^3.19.0",
     "eslint-config-egg": "^4.1.0",
-    "mm": "^2.1.0",
+    "mm": "^2.2.2",
     "mocha": "2",
     "nyc": "^11.0.2",
     "spy": "^1.0.0"

test/fixtures/prompt.js

@@ -0,0 +1,24 @@
+#!/usr/bin/env node
+
+'use strict';
+
+const readline = require('readline');
+
+const rl = readline.createInterface({
+  input: process.stdin,
+  output: process.stdout
+});
+
+ask('What\'s your name? ', answer => {
+  console.log(`hi, ${answer}`);
+  ask('How many coffee do you want? ', answer => {
+    console.log(`here is your ${answer} coffee`);
+    rl.close();
+    process.exit();
+  });
+});
+
+function ask(q, callback) {
+  process.send({ type: 'prompt' });
+  rl.question(q, callback);
+}