diff --git a/tests/TemplateDataBlobTest.php b/tests/TemplateDataBlobTest.php
index d19656bd..77d72670 100644
--- a/tests/TemplateDataBlobTest.php
+++ b/tests/TemplateDataBlobTest.php
@@ -11,37 +11,55 @@ class TemplateDataBlobTest extends MediaWikiTestCase {
 	}
 
 	public static function provideParse() {
-		return array(
+		$cases = array(
 			array(
-				'
-				{}
+				'input' => '[]
 				',
-				'
-				{}
-				',
-				'Empty object'
+				'status' => 'Property "templatedata" is expected to be of type "object".'
 			),
 			array(
-				'
-				{
+				'input' => '{
+					"params": {}
+				}
+				',
+				'output' => '{
+					"description": null,
+					"params": {}
+				}
+				',
+				'status' => true,
+				'msg' => 'Minimal valid blob'
+			),
+			array(
+				'input' => '{
+					"params": {},
 					"foo": "bar"
 				}
 				',
-				'
-				{}
-				',
-				'Unknown properties are stripped'
+				'status' => 'Unexpected property "foo".',
+				'msg' => 'Unknown properties'
 			),
 			array(
-				'
-				{
+				'input' => '{}',
+				'status' => 'Required property "params" not found.',
+				'msg' => 'Empty object'
+			),
+			array(
+				'input' => '{
+					"foo": "bar"
+				}
+				',
+				'status' => 'Unexpected property "foo".',
+				'msg' => 'Unknown properties invalidate the blob'
+			),
+			array(
+				'input' => '{
 					"params": {
 						"foo": {}
 					}
 				}
 				',
-				'
-				{
+				'output' => '{
 					"description": null,
 					"params": {
 						"foo": {
@@ -56,11 +74,10 @@ class TemplateDataBlobTest extends MediaWikiTestCase {
 					}
 				}
 				',
-				'Optional properties are added if missing'
+				'msg' => 'Optional properties are added if missing'
 			),
 			array(
-				'
-				{
+				'input' => '{
 					"description": "User badge MediaWiki developers.",
 					"params": {
 						"nickname": {
@@ -75,8 +92,7 @@ class TemplateDataBlobTest extends MediaWikiTestCase {
 					}
 				}
 				',
-				'
-				{
+				'output' => '{
 					"description": {
 						"en": "User badge MediaWiki developers."
 					},
@@ -97,11 +113,10 @@ class TemplateDataBlobTest extends MediaWikiTestCase {
 					}
 				}
 				',
-				'InterfaceText is expanded to langcode-keyed object, assuming content language'
+				'msg' => 'InterfaceText is expanded to langcode-keyed object, assuming content language'
 			),
 			array(
-				'
-				{
+				'input' => '{
 					"description": {
 						"en": "User badge MediaWiki developers."
 					},
@@ -122,11 +137,10 @@ class TemplateDataBlobTest extends MediaWikiTestCase {
 					}
 				}
 				',
-				'Fully normalised json should be valid input and stay unchanged'
+				'msg' => 'Fully normalised json should be valid input and stay unchanged'
 			),
 			array(
-				'
-				{
+				'input' => '{
 					"description": "Document the documenter.",
 					"params": {
 						"1d": {
@@ -141,8 +155,7 @@ class TemplateDataBlobTest extends MediaWikiTestCase {
 					}
 				}
 				',
-				'
-				{
+				'output' => '{
 					"description": {
 						"en": "Document the documenter."
 					},
@@ -172,75 +185,56 @@ class TemplateDataBlobTest extends MediaWikiTestCase {
 					}
 				}
 				',
-				'The inherits property copies over properties from another parameter (preserving overides)'
+				'msg' => 'The inherits property copies over properties from another parameter (preserving overides)'
 			),
 		);
+		$calls = array();
+		foreach ( $cases as $case ) {
+			$calls[] = array( $case );
+		}
+		return $calls;
 	}
 
 	/**
 	 * @dataProvider provideParse
 	 */
-	public function testParse( $input, $expected, $msg = null ) {
-		if ( !$msg ) {
-			$msg = $expected;
-			$expected = $input;
+	public function testParse( Array $cases ) {
+
+		// Expand defaults
+		if ( !isset( $cases['status'] ) ) {
+			$cases['status'] = true;
 		}
-		$t = TemplateDataBlob::newFromJSON( $input );
+		if ( !isset( $cases['msg'] ) ) {
+			$cases['msg'] = is_string( $cases['status'] ) ? $cases['status'] : 'TemplateData assertion';
+		}
+		if ( !isset( $cases['output'] ) ) {
+			if ( is_string( $cases['status'] ) ) {
+				$cases['output'] = '{}';
+			} else {
+				$cases['output'] = $cases['input'];
+			}
+		}
+
+		$t = TemplateDataBlob::newFromJSON( $cases['input'] );
 		$actual = $t->getJSON();
-		$this->assertJsonStringEqualsJsonString(
-			$expected,
-			$actual,
-			$msg
-		);
-	}
-
-	public static function provideStatus() {
-		return array(
-			array(
-				'
-				[]
-				',
-				false,
-				'Not an object'
-			),
-			array(
-				'
-				{
-					"params": {}
-				}
-				',
-				true,
-				'Minimal valid blob'
-			),
-			array(
-				'
-				{
-					"params": {},
-					"foo": "bar"
-				}
-				',
-				false,
-				'Unknown properties'
-			),
-		);
-	}
-
-	/**
-	 * @dataProvider provideStatus
-	 */
-	public function testStatus( $inputJSON, $isGood, $msg ) {
-		// Make sure we don't have two errors cancelling each other out
-		if ( json_decode( $inputJSON ) === null ) {
-			throw new Exception( 'Test case provided invalid JSON.' );
-		}
-
-		$t = TemplateDataBlob::newFromJSON( $inputJSON );
 		$status = $t->getStatus();
-
-		$this->assertEquals(
-			$status->isGood(),
-			$isGood,
-			$msg
+		if ( !$status->isGood() ) {
+			$this->assertEquals(
+				$cases['status'],
+				$status->getHtml(),
+				'Status: ' . $cases['msg']
+			);
+		} else {
+			$this->assertEquals(
+				$cases['status'],
+				$status->isGood(),
+				'Status: ' . $cases['msg']
+			);
+		}
+		$this->assertJsonStringEqualsJsonString(
+			$cases['output'],
+			$actual,
+			$cases['msg']
 		);
 	}
 }