Allow skipping unit tests and support 'repeat' workflow arguments

Summary:
We run all tests before deploy but some of them are expected to fail.
We need to skip them.
It can be useful also for someone else.

I don't propagate this to `arc diff` as that would be much more complicated - we would need a new state 'partially skipped'.

The 'path' argument needs to be a file, skipping whole dirs is not supported.
The 'path' argument is in fact engine specific and engines can support format like 'Class::testMethod' but I didn't bother to document it to not confuse people.

Test Plan:
`arc unit --skip test.php`
`arc unit --skip ../src/test.php`

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D2673

src/unit/engine/ArcanistBaseUnitTestEngine.php

@@ -25,6 +25,7 @@ abstract class ArcanistBaseUnitTestEngine {
 
   private $workingCopy;
   private $paths;
+  private $skipFiles;
   private $arguments = array();
   protected $diffID;
   private $enableAsyncTests;
@@ -54,6 +55,15 @@ abstract class ArcanistBaseUnitTestEngine {
     return $this->paths;
   }
 
+  final public function setSkipFiles(array $paths) {
+    $this->skipFiles = $paths;
+    return $this;
+  }
+
+  final public function getSkipFiles() {
+    return $this->skipFiles;
+  }
+
   final public function setArguments(array $arguments) {
     $this->arguments = $arguments;
     return $this;

src/unit/engine/PhutilUnitTestEngine.php

@@ -77,6 +77,13 @@ final class PhutilUnitTestEngine extends ArcanistBaseUnitTestEngine {
       } while ($library_path != '.');
     }
 
+    $skip = array();
+    foreach ($this->getSkipFiles() as $skip_path) {
+      $skip_path = Filesystem::resolvePath($skip_path);
+      $skip_path = Filesystem::readablePath($skip_path, $library_root);
+      $skip[$skip_path] = true;
+    }
+
     // Look for any class that extends ArcanistPhutilTestCase inside a
     // __tests__ directory in any parent directory of every affected file.
     //
@@ -100,6 +107,9 @@ final class PhutilUnitTestEngine extends ArcanistBaseUnitTestEngine {
         ->selectAndLoadSymbols();
 
       foreach ($symbols as $symbol) {
+        if (isset($skip[$symbol['where']])) {
+          continue;
+        }
         $run_tests[$symbol['name']] = true;
       }
     }

src/workflow/ArcanistBaseWorkflow.php

@@ -532,11 +532,7 @@ abstract class ArcanistBaseWorkflow {
   }
 
   public function getArgument($key, $default = null) {
-    $args = $this->arguments;
-    if (!array_key_exists($key, $args)) {
-      return $default;
-    }
-    return $args[$key];
+    return idx($this->arguments, $key, $default);
   }
 
   final public function getCompleteArgumentSpecification() {
@@ -567,6 +563,12 @@ abstract class ArcanistBaseWorkflow {
       }
     }
 
+    foreach ($spec as $long => $options) {
+      if (!empty($options['repeat'])) {
+        $dict[$long] = array();
+      }
+    }
+
     $more = array();
     for ($ii = 0; $ii < count($args); $ii++) {
       $arg = $args[$ii];
@@ -603,7 +605,11 @@ abstract class ArcanistBaseWorkflow {
           throw new ArcanistUsageException(
             "Option '{$arg}' requires a parameter.");
         }
+        if (!empty($options['repeat'])) {
+          $dict[$arg_key][] = $args[$ii + 1];
+        } else {
           $dict[$arg_key] = $args[$ii + 1];
+        }
         $ii++;
       }
     }

src/workflow/ArcanistUnitWorkflow.php

@@ -68,6 +68,11 @@ EOTEXT
         'help' =>
           "Override configured unit engine for this project."
       ),
+      'skip' => array(
+        'param' => 'path',
+        'help' => "Specify file paths that will be ignored.",
+        'repeat' => true,
+      ),
       'coverage' => array(
         'help' => 'Always enable coverage information.',
         'conflicts' => array(
@@ -127,6 +132,7 @@ EOTEXT
     $this->engine = newv($engine_class, array());
     $this->engine->setWorkingCopy($working_copy);
     $this->engine->setPaths($paths);
+    $this->engine->setSkipFiles($this->getArgument('skip'));
     $this->engine->setArguments($this->getPassthruArgumentsAsMap('unit'));
 
     $enable_coverage = null; // Means "default".