Add missing exception tests

tests/Exception/InvalidDeclarationNametest.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace AmpProject\Exception;
+
+use AmpProject\Tests\TestCase;
+
+/**
+ * Test the InvalidDeclarationName exception.
+ *
+ * @covers \AmpProject\Exception\InvalidDeclarationName
+ * @package ampproject/amp-toolbox
+ */
+class InvalidDeclarationNameTest extends TestCase
+{
+
+    /**
+     * Test throwing the exception for an invalid declaration name.
+     */
+    public function testThrowingForDeclarationName()
+    {
+        $this->expectException(InvalidDeclarationName::class);
+        $this->expectExceptionMessage(
+            "Invalid declaration name 'declarationName' was requested from the validator spec."
+        );
+
+        throw InvalidDeclarationName::forDeclaration('declarationName');
+    }
+}

tests/Exception/InvalidDocRulesetNameTest.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace AmpProject\Exception;
+
+use AmpProject\Tests\TestCase;
+
+/**
+ * Test the InvalidDocRulesetName exception.
+ *
+ * @covers \AmpProject\Exception\InvalidDocRulesetName
+ * @package ampproject/amp-toolbox
+ */
+class InvalidDocRulesetNameTest extends TestCase
+{
+
+    /**
+     * Test throwing the exception for a document ruleset name.
+     */
+    public function testThrowingForDocRulesetName()
+    {
+        $this->expectException(InvalidDocRulesetName::class);
+        $this->expectExceptionMessage("Invalid document ruleset name 'docName' was requested from the validator spec.");
+
+        throw InvalidDocRulesetName::forDocRulesetName('docName');
+    }
+}