diff --git a/src/lint/linter/__tests__/ArcanistLinterTestCase.php b/src/lint/linter/__tests__/ArcanistLinterTestCase.php
--- a/src/lint/linter/__tests__/ArcanistLinterTestCase.php
+++ b/src/lint/linter/__tests__/ArcanistLinterTestCase.php
@@ -128,78 +128,87 @@
     $this->compareTransform($xform, $after_lint);
   }
 
-  private function compareLint($file, $expect, ArcanistLintResult $result) {
-    $seen = array();
+  private function compareLint($file, $expect, ArcanistLintResult $results) {
+    $expected_results = new ArcanistLintResult();
+
     $raised = array();
-    $message_map = array();
-
-    foreach ($result->getMessages() as $message) {
-      $sev = $message->getSeverity();
-      $line = $message->getLine();
-      $char = $message->getChar();
-      $code = $message->getCode();
-      $name = $message->getName();
-      $message_key = $sev.':'.$line.':'.$char;
-      $message_map[$message_key] = $message;
-      $seen[] = $message_key;
-      $raised[] = sprintf(
-        '  %s: %s %s',
-        pht('%s at line %d, char %d', $sev, $line, $char),
-        $code,
-        $name);
+    if (!$raised) {
+      $raised = array('No messages.');
     }
+    $raised = sprintf(
+      "%s:\n%s",
+      pht('Actually raised'),
+      implode("\n", $raised));
+
     $expect = trim($expect);
     if ($expect) {
       $expect = explode("\n", $expect);
     } else {
       $expect = array();
     }
-    foreach ($expect as $key => $expected) {
-      $expect[$key] = head(explode(' ', $expected));
-    }
+    foreach ($expect as $result) {
+      $parts = explode(':', $result);
 
-    $expect = array_fill_keys($expect, true);
-    $seen   = array_fill_keys($seen, true);
+      $message = id(new ArcanistLintMessage())
+        ->setSeverity(idx($parts, 0));
 
-    if (!$raised) {
-      $raised = array(pht('No messages.'));
-    }
-    $raised = sprintf(
-      "%s:\n%s",
-      pht('Actually raised'),
-      implode("\n", $raised));
+      if (idx($parts, 1)) {
+        $message->setLine((int)idx($parts, 1));
+      }
+      if (idx($parts, 2)) {
+        $message->setChar((int)idx($parts, 2));
+      }
+      if (idx($parts, 3)) {
+        $message->setCode(idx($parts, 3));
+      }
 
-    foreach (array_diff_key($expect, $seen) as $missing => $ignored) {
-      list($sev, $line, $char) = explode(':', $missing);
-      $this->assertFailure(
-        pht(
-          "In '%s', expected lint to raise %s on line %d at char %d, ".
-          "but no %s was raised. %s",
-          $file,
-          $sev,
-          $line,
-          $char,
-          $sev,
-          $raised));
+      $expected_results->addMessage($message);
     }
 
-    foreach (array_diff_key($seen, $expect) as $surprising => $ignored) {
-      $message = $message_map[$surprising];
-      $message_info = $message->getDescription();
+    if (
+      ArcanistLinterTestCase::compareLintResults($expected_results, $results) ||
+      ArcanistLinterTestCase::compareLintResults($results, $expected_results)) {
+
+      $expected = 'Expected to raise';
+      if ($expected_results) {
+        foreach ($expected_results->getMessages() as $message) {
+          $expected .= sprintf(
+            "\n  %s: %s %s",
+            pht(
+              '%s at line %d, char %d',
+              $message->getSeverity(),
+              $message->getLine(),
+              $message->getChar()),
+            $message->getCode(),
+            $message->getName());
+        }
+      } else {
+        $expected .= sprintf("\n  %s", pht('No messages'));
+      }
+
+      $actual = 'Actually raised';
+      if ($results) {
+        foreach ($results->getMessages() as $message) {
+          $actual .= sprintf(
+            "\n  %s: %s %s",
+            pht(
+              '%s at line %d, char %d',
+              $message->getSeverity(),
+              $message->getLine(),
+              $message->getChar()),
+            $message->getCode(),
+            $message->getName());
+        }
+      } else {
+        $actual .= sprintf("\n  %s", pht('No messages'));
+      }
 
-      list($sev, $line, $char) = explode(':', $surprising);
       $this->assertFailure(
         sprintf(
-          "%s:\n\n%s\n\n%s",
-          pht(
-            "In '%s', lint raised %s on line %d at char %d, ".
-            "but nothing was expected",
-            $file,
-            $sev,
-            $line,
-            $char),
-          $message_info,
-          $raised));
+            "%s\n\n%s\n\n%s",
+            pht("Lint failed for '%s'.", $file),
+            $expected,
+            $actual));
     }
   }
 
@@ -213,4 +222,95 @@
       pht('File as patched by lint did not match the expected patched file.'));
   }
 
+  /**
+   * Compare two @{class:ArcanistLintResult} instances.
+   *
+   * @param  ArcanistLintResult $results1 [description]
+   * @param  ArcanistLintResult $results2 [description]
+   * @return [type]                       [description]
+   */
+  private static function compareLintResults(
+    ArcanistLintResult $results1,
+    ArcanistLintResult $results2) {
+
+    $diff = array();
+
+    $messages1 = $results1->getMessages();
+    $messages2 = $results2->getMessages();
+
+    foreach ($messages1 as $x) {
+      $found = false;
+
+      // This relies on the sorted order returned by ArcanistLintMessage.
+      while (
+        $x->getLine() > head($messages2)->getLine() ||
+        (
+          $x->getLine() === head($messages2)->getLine() &&
+          $x->getChar() > head($messages2)->getChar())) {
+        array_shift($messages2);
+      }
+
+      foreach ($messages2 as $y) {
+        if ($x->getLine() < $y->getLine()) {
+          break;
+        } else if ($x->getLine() > $y->getLine()) {
+          continue;
+        }
+
+        if ($x->getChar() < $y->getChar()) {
+          break;
+        } else if ($x->getChar() > $y->getChar()) {
+          continue;
+        }
+
+        if ($x->getSeverity() != $y->getSeverity()) {
+          continue;
+        }
+
+        if (!ArcanistLinterTestCase::compareLintMessageDetail(
+          $x->getCode(),
+          $y->getCode())) {
+
+          continue;
+        }
+
+        if (!ArcanistLinterTestCase::compareLintMessageDetail(
+          $x->getName(),
+          $y->getName())) {
+
+          continue;
+        }
+
+        $found = true;
+        break;
+      }
+
+      if (!$found) {
+        $diff[] = $x;
+      }
+    }
+
+    return $diff;
+  }
+
+  /**
+   * Compare properties of @{class:ArcanistLintMessage} instances.
+   *
+   * The expectation is that if one (or both) of the properties is null, then
+   * we don't care about its value.
+   *
+   * @param  wild
+   * @param  wild
+   * @return bool
+   */
+  private static function compareLintMessageDetail($x, $y) {
+    if ($x === null || $y === null) {
+      return true;
+    } else if ($x === $y) {
+      return true;
+    } else {
+      return false;
+    }
+  }
+
 }