add a nightmarish test

src/matrix/render.clj

@@ -191,3 +191,5 @@
        :mul  (pretty-mul  inner)
        :add  (pretty-add  inner))))
   ([op _] (with-inc-row-indices op)))
+
+;TODO: better row formatting (each column is only as wide as the longest in the column)

test/matrix/core_test.clj

@@ -26,4 +26,12 @@
            (map-matrix int
                        (auto-final
                         [[2  3 15]
-                         [1 -1  0]]))))))
+                         [1 -1  0]])))))
+  (testing "A nightmare"
+    ; https://www.desmos.com/calculator/17l6cwgtgc
+    (is (= [[1 0 0 -14/5]
+            [0 1 0   6/5]
+            [0 0 1  46/5]]
+           (auto-final [[3  1 1 2]
+                        [1 -2 1 4]
+                        [-1  1 0 4]])))))