Max out Array test coverage.

Of course the untested part has a bug.

src/Magnum/Array.h

@@ -201,12 +201,12 @@ template<class T> class Array3D: public Array<3, T> {
 
 /** @debugoperator{Array} */
 template<UnsignedInt dimensions, class T> Debug& operator<<(Debug& debug, const Array<dimensions, T>& value) {
-    debug << "Array(" << Corrade::Utility::Debug::nospace;
+    debug << "Array(" << Debug::nospace;
     for(UnsignedInt i = 0; i != dimensions; ++i) {
-        if(i != 0) debug << ",";
+        if(i != 0) debug << Debug::nospace << ",";
         debug << value[i];
     }
-    return debug << Corrade::Utility::Debug::nospace << ")";
+    return debug << Debug::nospace << ")";
 }
 
 /** @debugoperator{Array1D} */

src/Magnum/Test/ArrayTest.cpp

@@ -23,6 +23,7 @@
     DEALINGS IN THE SOFTWARE.
 */
 
+#include <sstream>
 #include <Corrade/TestSuite/Tester.h>
 
 #include "Magnum/Array.h"
@@ -35,6 +36,8 @@ struct ArrayTest: TestSuite::Tester {
     void construct();
     void equality();
     void access();
+
+    void debug();
 };
 
 typedef Magnum::Array1D<Int> Array1D;
@@ -44,7 +47,9 @@ typedef Magnum::Array3D<Int> Array3D;
 ArrayTest::ArrayTest() {
     addTests({&ArrayTest::construct,
               &ArrayTest::equality,
-              &ArrayTest::access});
+              &ArrayTest::access,
+
+              &ArrayTest::debug});
 }
 
 void ArrayTest::construct() {
@@ -109,6 +114,13 @@ void ArrayTest::access() {
     CORRADE_COMPARE(cc.xy(), Array2D(-5, 6));
 }
 
+void ArrayTest::debug() {
+    std::ostringstream out;
+
+    Debug{&out} << Array<4, Int>{5, 6, 7, 8} << Array1D{13} << Array2D{71, 2} << Array3D{1, 2, 3};
+    CORRADE_COMPARE(out.str(), "Array(5, 6, 7, 8) Array(13) Array(71, 2) Array(1, 2, 3)\n");
+}
+
 }}
 
 CORRADE_TEST_MAIN(Magnum::Test::ArrayTest)