Support deprecated prompt config option.

Fixes #755

Author: bobthecow

src/Configuration.php

@@ -127,6 +127,7 @@ class Configuration
     private $presenter;
     private $autoCompleter;
     private $checker;
+    /** @deprecated */
     private $prompt;
     private $configPaths;
 
@@ -1628,11 +1629,19 @@ public function getStartupMessage()
     /**
      * Set the prompt.
      *
-     * @param string $prompt
+     * @deprecated The `prompt` configuration has been replaced by Themes and support will
+     * eventually be removed. In the meantime, prompt is applied first by the Theme, then overridden
+     * by any explicitly defined prompt.
+     *
+     * Note that providing a prompt but not a theme config will implicitly use the `classic` theme.
      */
     public function setPrompt(string $prompt)
     {
         $this->prompt = $prompt;
+
+        if (isset($this->theme)) {
+            $this->theme->setPrompt($prompt);
+        }
     }
 
     /**
@@ -1676,6 +1685,10 @@ public function setTheme($theme)
 
         $this->theme = $theme;
 
+        if (isset($this->prompt)) {
+            $this->theme->setPrompt($this->prompt);
+        }
+
         if (isset($this->output)) {
             $this->output->setTheme($theme);
             $this->applyFormatterStyles();
@@ -1688,7 +1701,12 @@ public function setTheme($theme)
     public function theme(): Theme
     {
         if (!isset($this->theme)) {
-            $this->theme = new Theme();
+            // If a prompt is explicitly set, and a theme is not, base it on the `classic` theme.
+            $this->theme = $this->prompt ? new Theme('classic') : new Theme();
+        }
+
+        if (isset($this->prompt)) {
+            $this->theme->setPrompt($this->prompt);
         }
 
         return $this->theme;

src/functions.php

@@ -226,6 +226,17 @@ function info(Configuration $config = null)
             'output decorated' => $config->getOutputDecorated(),
             'output verbosity' => $config->verbosity(),
             'output pager'     => $config->getPager(),
+            'theme'            => $themeConfig,
+        ];
+
+        $theme = $config->theme();
+        // TODO: show styles (but only if they're different than default?)
+        $output['theme'] = [
+            'compact'      => $theme->compact(),
+            'prompt'       => $theme->prompt(),
+            'bufferPrompt' => $theme->bufferPrompt(),
+            'replayPrompt' => $theme->replayPrompt(),
+            'returnValue'  => $theme->returnValue(),
         ];
 
         $pcntl = [

test/ShellTest.php

@@ -238,9 +238,7 @@ public function testRenderingExceptions()
         $streamContents = \stream_get_contents($stream);
 
         $expected = <<<EOF
-
-   PARSE ERROR  PHP Parse error: message in test/ShellTest.php on line 224.
-
+ PARSE ERROR  PHP Parse error: message in test/ShellTest.php on line 224.
 
 EOF;