Implement the support for inspecting unstaged changes via --sniff_unstaged.

Author: zaantar

README.md

@@ -32,6 +32,7 @@ Options:
 - `--standard[=<arg>]`: Name of the phpcs standard to use: 'WordPress', 'WordPress-VIP', 'WordPress-Core', 'WordPress-Docs', 'WordPress-Extra', 'Toolset'
 - `--log_level[=<arg>]`: Control verbosity by passing a number from 0 (most verbose) to 2 (least verbose, only errors).
 - `--ignore_space_changes`: Whitespace changes will be ignored when git is used to produce the diff.
+- `--sniff_unstaged`: Inspect unstaged changes in the working directory against the latest commit (HEAD). `--start_revision` and `--end_revision` will be ignored in this case.
 
 Limitations:
 

bin/phpcs-diff

@@ -39,7 +39,8 @@ $getopt = new \GetOpt\GetOpt(
         [ 't', 'tolerance' ],
         [ 'standard' ],
         [ 'log_level' ],
-        [ 'ignore_space_changes' ]
+        [ 'ignore_space_changes', \GetOpt\GetOpt::NO_ARGUMENT ],
+        [ 'sniff_unstaged', \GetOpt\GetOpt::NO_ARGUMENT ],
 	]
 );
 
@@ -62,9 +63,6 @@ $getopt->getOption( 'log_level', true )
 	->setValidation( 'is_numeric' )
 	->setDefaultValue( LoggerInterface::WARNING );
 
-$getopt->getOption( 'ignore_space_changes', true )
-    ->setMode( \GetOpt\GetOpt::NO_ARGUMENT );
-
 try {
 	$getopt->process();
 } catch ( \GetOpt\ArgumentException $exception ) {
@@ -79,6 +77,12 @@ $phpcs_standard = $getopt->getOption( 'standard' );
 $log_level = $getopt->getOption( 'log_level' );
 $ignore_space_changes = $getopt->offsetExists( 'ignore_space_changes' );
 
+$sniff_unstaged = $getopt->offsetExists( 'sniff_unstaged' );
+if( $sniff_unstaged ) {
+    $start_revision = 'HEAD';
+    $end_revision = Backends\Git::UNSTAGED;
+}
+
 $logger = new Log\ShellLogger( (int) $log_level );
 $options = [ 'ignore-space-change' => $ignore_space_changes ];
 $version_control = new Backends\Git( '', $logger, $options );

inc/backends/Git.php

@@ -23,6 +23,9 @@ class Git implements BackendInterface {
 	/** @var string This is how the unified diff annotates files that didn't exist at a particular revision. */
 	const DEV_NULL = '/dev/null';
 
+	/** @var string Represents unstaged changes in the working directory. */
+	const UNSTAGED = '*UNSTAGED*';
+
 	/** @var LoggerInterface */
 	private $log;
 
@@ -68,11 +71,15 @@ public function get_diff( $directory, $end_commit, $start_commit = null, $option
 			$arg_ignore_whitespace = '';
 		}
 
+		if( self::UNSTAGED === $end_commit ) {
+			return $this->get_diff_for_unstaged_changes( "$arg_git_dir $arg_ignore_whitespace", $start_commit );
+		}
+
 		// Check if we're comparing the the same commit and show a message about it.
 		//
 		// We need to use git rev-parse in case a branch name or HEAD are provided.
-		$start_commit_hash = shell_exec( "git $arg_git_dir rev-parse $start_commit" );
-		$end_commit_hash = shell_exec( "git $arg_git_dir rev-parse $end_commit" );
+		$start_commit_hash = trim( shell_exec( "git $arg_git_dir rev-parse $start_commit" ) );
+		$end_commit_hash = trim( shell_exec( "git $arg_git_dir rev-parse $end_commit" ) );
 		if( $start_commit_hash === $end_commit_hash ) {
 			$this->log->log( LoggerInterface::ERROR, "Attempting to compare a commit $start_commit_hash with itself. Expect an empty result." );
 		}
@@ -91,6 +98,24 @@ public function get_diff( $directory, $end_commit, $start_commit = null, $option
 		return $diff;
 	}
 
+
+	/**
+	 * Get a diff between a selected commit and unstaged changes.
+	 *
+	 * @param string $git_args
+	 * @param string $start_commit Revision number to diff against.
+	 *
+	 * @return string
+	 */
+	private function get_diff_for_unstaged_changes( $git_args, $start_commit ) {
+		$command = "git diff --unified=0 $git_args $start_commit";
+
+		$this->log->log( LoggerInterface::INFO, 'Generating a diff between unstaged changes and the selected commit: ' . $command );
+
+		$diff = shell_exec( $command );
+		return $diff;
+	}
+
 	/**
 	 * Collect information about the diff.
 	 *
@@ -152,11 +177,17 @@ public function run_phpcs_for_file_at_revision( $filename, $revision, $phpcs_com
 			$filename, $revision
 		) );
 
-		$git_command = sprintf(
-			'git show --format=raw %s:%s',
-			$revision,
-			ltrim( $filename, '/' )
-		);
+		if( self::UNSTAGED === $revision ) {
+			// Inspecting an unstaged file - just take it from the filesystem directly.
+			$get_file_command = 'cat ' . ltrim( $filename, '/' );
+		} else {
+			// Get the content of the file at a particular commit.
+			$get_file_command = sprintf(
+				'git show --format=raw %s:%s',
+				$revision,
+				ltrim( $filename, '/' )
+			);
+		}
 
 		$phpcs_command = sprintf(
 			'%s --report=json --runtime-set installed_paths %s --standard=%s --stdin-path=%s -',
@@ -166,7 +197,7 @@ public function run_phpcs_for_file_at_revision( $filename, $revision, $phpcs_com
 			escapeshellarg( $filename )
 		);
 
-		$command_string = "$git_command | $phpcs_command";
+		$command_string = "$get_file_command | $phpcs_command";
 
 		return shell_exec( $command_string );
 	}

inc/log/ShellLogger.php

@@ -26,8 +26,10 @@ public function log( $severity, $message ) {
 
 		switch( $severity ) {
 			case LoggerInterface::ERROR:
+				file_put_contents('php://stderr', 'ERROR: ' .$message . PHP_EOL );
+				break;
 			case LoggerInterface::WARNING:
-				file_put_contents('php://stderr', $message . PHP_EOL );
+				file_put_contents('php://stderr', 'WARNING: ' .$message . PHP_EOL );
 				break;
 			default:
 				file_put_contents('php://stdout', $message . PHP_EOL );