Test all IP directions

.clang-format

@@ -13,6 +13,7 @@ ColumnLimit: 120
 Cpp11BracedListStyle: false
 EmptyLineBeforeAccessModifier: Never
 ForEachMacros: # It doesn't particularly matter if these are ForEachMacros or IfMacros
+  # No idea why test_iter doesn't need to be here but the other two do.
   - testcase
   - testgroup
 IndentWidth: 4
@@ -22,5 +23,7 @@ MaxEmptyLinesToKeep: 2
 SpaceAfterTemplateKeyword: false
 WhitespaceSensitiveMacros:
   - STRING_NAME
+  - test_iter
   - testcase
   - testgroup
+  - TEST_ITEM

tests/unit/ip_movement.hh

@@ -3,25 +3,36 @@
 #include <program_walker.hh>
 #include "test-framework/test_framework.hh"
 
-testgroup (ip_advance) {
-    testcase (sample_program) {
-        /*
-         * From the README:
-         *    0
-         *   1 4
-         *  2 5 7
-         * 3 6 8 9
-         */
-        program p("0142573689");
-        program_walker::instruction_pointer ip{ { SIZE_C(0), SIZE_C(0) }, direction::southwest };
+namespace {
+// Thank you clang-format very cool
+#define TEST_ITEM(dir, prog) \
+    { \
+#dir, { direction::dir, program(prog) } \
+    }
+
+// Each test program consists of every digit 0-9 exactly once, in the order they are hit if the IP is traveling in the
+// given direction from the top corner.
+std::initializer_list<std::pair<const char*, std::pair<direction, program>>> test_programs = {
+    TEST_ITEM(southwest, "0142573689"),
+    TEST_ITEM(west, "0215439876"),
+    TEST_ITEM(northwest, "0395286417"),
+    TEST_ITEM(northeast, "0968537421"),
+    TEST_ITEM(east, "0895671234"),
+    TEST_ITEM(southeast, "0715824693"),
+};
+
+#undef TEST_ITEM
+}  // namespace
 
-        for (int24_t i = '0'; i <= '9'; ++i) {
-            test_assert(p.at(ip.coords.first, ip.coords.second) == i);
-            program_walker::advance(ip, p.side_length());
-        }
+test_iter(ip_advance, test_programs, input) {
+    program& p = input.second;
+    program_walker::instruction_pointer ip{ { SIZE_C(0), SIZE_C(0) }, input.first };
 
-        test_assert(ip.coords.first == 0 && ip.coords.second == 0);
+    for (int24_t i = '0'; i <= '9'; ++i) {
+        test_assert(p.at(ip.coords.first, ip.coords.second) == i);
+        program_walker::advance(ip, p.side_length());
     }
+    test_assert(ip.coords.first == 0 && ip.coords.second == 0);
 };
 
 // TODO: Add tests for branch instructions