Restore ANSI highlighting of lint sections to lint output

Summary: Fixes T9846. This restores the last missing feature, ANSI highlighting of diff sections.

Test Plan:
Added a mode so we can actually test this stuff, activated that mode, wrote unit tests.

Did a bunch of actual lint locally too and looked at it, all seemed sane.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9846

Differential Revision: https://secure.phabricator.com/D18512

src/lint/renderer/ArcanistConsoleLintRenderer.php

@@ -6,12 +6,22 @@
 final class ArcanistConsoleLintRenderer extends ArcanistLintRenderer {
 
   private $showAutofixPatches = false;
+  private $testableMode;
 
   public function setShowAutofixPatches($show_autofix_patches) {
     $this->showAutofixPatches = $show_autofix_patches;
     return $this;
   }
 
+  public function setTestableMode($testable_mode) {
+    $this->testableMode = $testable_mode;
+    return $this;
+  }
+
+  public function getTestableMode() {
+    return $this->testableMode;
+  }
+
   public function renderLintResult(ArcanistLintResult $result) {
     $messages = $result->getMessages();
     $path = $result->getPath();
@@ -90,6 +100,7 @@ final class ArcanistConsoleLintRenderer extends ArcanistLintRenderer {
 
     $old = $data;
     $old_lines = phutil_split_lines($old);
+    $old_impact = substr_count($original, "\n") + 1;
     $start = $line;
 
     if ($message->isPatchable()) {
@@ -105,9 +116,26 @@ final class ArcanistConsoleLintRenderer extends ArcanistLintRenderer {
       // Figure out how many "-" and "+" lines we have by counting the newlines
       // for the relevant patches. This may overestimate things if we are adding
       // or removing entire lines, but we'll adjust things below.
-      $old_impact = substr_count($original, "\n") + 1;
       $new_impact = substr_count($replacement, "\n") + 1;
 
+
+      // If this is a change on a single line, we'll try to highlight the
+      // changed character range to make it easier to pick out.
+      if ($old_impact === 1 && $new_impact === 1) {
+        $old_lines[$start - 1] = substr_replace(
+          $old_lines[$start - 1],
+          $this->highlightText($original),
+          $char - 1,
+          strlen($original));
+
+        $new_lines[$start - 1] = substr_replace(
+          $new_lines[$start - 1],
+          $this->highlightText($replacement),
+          $char - 1,
+          strlen($replacement));
+      }
+
+
       // If lines at the beginning of the changed line range are actually the
       // same, shrink the range. This happens when a patch just adds a line.
       do {
@@ -154,6 +182,18 @@ final class ArcanistConsoleLintRenderer extends ArcanistLintRenderer {
       } while (true);
 
     } else {
+
+      // If we have "original" text and it is contained on a single line,
+      // highlight the affected area. If we don't have any text, we'll mark
+      // the character with a caret (below, in rendering) instead.
+      if ($old_impact == 1 && strlen($original)) {
+        $old_lines[$start - 1] = substr_replace(
+          $old_lines[$start - 1],
+          $this->highlightText($original),
+          $char - 1,
+          strlen($original));
+      }
+
       $old_impact = 0;
       $new_impact = 0;
     }
@@ -263,4 +303,12 @@ final class ArcanistConsoleLintRenderer extends ArcanistLintRenderer {
     return $line_map;
   }
 
+  private function highlightText($text) {
+    if ($this->getTestableMode()) {
+      return '>'.$text.'<';
+    } else {
+      return (string)tsprintf('##%s##', $text);
+    }
+  }
+
 }

src/lint/renderer/__tests__/ArcanistConsoleLintRendererTestCase.php

@@ -61,6 +61,12 @@ final class ArcanistConsoleLintRendererTestCase
         'name' => 'Fruit Misinformation',
         'description' => 'Arguably untrue.',
       ),
+
+      'original' => array(
+        'line' => 1,
+        'char' => 4,
+        'original' => 'should of',
+      ),
     );
 
     $defaults = array(
@@ -105,7 +111,8 @@ final class ArcanistConsoleLintRendererTestCase
         ->setData($data)
         ->addMessage($message);
 
-      $renderer = new ArcanistConsoleLintRenderer();
+      $renderer = id(new ArcanistConsoleLintRenderer())
+        ->setTestableMode(true);
 
       try {
         PhutilConsoleFormatter::disableANSI(true);

src/lint/renderer/__tests__/data/inline.expect

@@ -4,5 +4,5 @@
    Warning  (WARN123) Lint Warning
     Consider this.
 
-    >>> -      1 adjudicated
+    >>> -      1 adjudi>cat<ed
-        +        adjudidoged
+        +        adjudi>dog<ed

src/lint/renderer/__tests__/data/original.expect

@@ -0,0 +1,7 @@
+>>> Lint for path/to/example.c:
+
+
+   Warning  (WARN123) Lint Warning
+    Consider this.
+
+    >>>        1 He >should of< known.

src/lint/renderer/__tests__/data/original.txt

@@ -0,0 +1 @@
+He should of known.

src/lint/renderer/__tests__/data/overlap.expect

@@ -4,5 +4,5 @@
    Warning  (WARN123) Lint Warning
     Consider this.
 
-    >>> -      1 tantawount
+    >>> -      1 tanta>w<ount
-        +        tantamount
+        +        tanta>m<ount

src/lint/renderer/__tests__/data/simple.expect

@@ -4,7 +4,7 @@
    Warning  (WARN123) Lint Warning
     Consider this.
 
-    >>> -      1 a
+    >>> -      1 >a<
-        +        z
+        +        >z<
                2 b
                3 c