--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/+blockmatrix/isBlockmatrixTest.m	Fri Sep 07 14:40:58 2018 +0200
@@ -0,0 +1,67 @@
+function tests = isBlockmatrixTest()
+    tests = functiontests(localfunctions);
+end
+
+function testIsBlockmatrix(testCase)
+    cases = {
+        {
+            magic(3),
+            false % Must be a cell array
+        }
+        {
+            {[2 2 2];{1,2}},
+            false % All elements of the cell matrix must be regular matrices
+        },
+        {
+            {[2 2 2];[1 2]},
+            false % Row dimensions must match
+        },
+        {
+            {[2; 2; 2], [1; 2]},
+            false % Column dimensions must match
+        },
+        {
+            {},
+            true % An empty matrix is a matrix too
+        },
+        {
+            {
+            [2 2; 2 1], [1; 2];
+            [2 2], [1]
+            },
+            true % A simple valid one
+        },
+        {
+            {
+            [2 2; 2 1], [];
+            [2 2], [1]
+            },
+            true % Empty blocks assumed to be zero and match dimensions
+        },
+        {
+            {
+            [2 2; 2 1], [];
+            [2 2], []
+            },
+            true % Empty blocks allowed.
+        },
+        {
+            {
+            [2 2; 2 1], [1; 2];
+            [], []
+            },
+            true % Empty blocks allowed.
+        },
+        {
+            blockmatrix.zero({[1 2 3],[2 3]}),
+            true % A zero block matrix is a block matrix
+        },
+    };
+
+    for i = 1:length(cases)
+        in = cases{i}{1};
+        out = blockmatrix.isBlockmatrix(in);
+        expected = cases{i}{2};
+        testCase.verifyEqual(out, expected, sprintf('Should return %d for %s', expected, toString(in)));
+    end
+end
\ No newline at end of file