From b544bbdf40214e9601aaff374b9f1ee2723e2189 Mon Sep 17 00:00:00 2001
From: Jackson Moore <jacksonmoore@tuta.io>
Date: Fri, 4 Sep 2026 11:11:22 +0200
Subject: Verify reverse request matrix

---
 lua/clever_f/repeat_resolver.lua | 22 +++++++++++++---------
 tests/run.lua                    | 27 +++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/lua/clever_f/repeat_resolver.lua b/lua/clever_f/repeat_resolver.lua
index 6b2b2f6..5f6a160 100644
--- a/lua/clever_f/repeat_resolver.lua
+++ b/lua/clever_f/repeat_resolver.lua
@@ -198,22 +198,26 @@ local function sampled_fixed_direction(resolver)
   return fixed
 end
 
-function M.primary_direction(stored_descriptor, pressed_key, fix_key_direction)
+function M.reverse_request(stored_descriptor, pressed_key, fix_key_direction)
   local stored = domain.Descriptor.from_string(stored_descriptor)
   local pressed = domain.Descriptor.from_string(pressed_key)
   if type(fix_key_direction) ~= "boolean" then
     fail("fix_key_direction must be a Boolean", 2)
   end
-  if not fix_key_direction then
-    if domain.Descriptor.is_lowercase(pressed) then
-      return stored
-    end
-    return domain.Descriptor.swap(stored)
+
+  local reverse = domain.Descriptor.is_uppercase(pressed)
+  if fix_key_direction and domain.Descriptor.is_uppercase(stored) then
+    reverse = not reverse
   end
-  if domain.Descriptor.is_lowercase(pressed) then
-    return domain.Descriptor.lowercase(stored)
+  return reverse
+end
+
+function M.primary_direction(stored_descriptor, pressed_key, fix_key_direction)
+  local stored = domain.Descriptor.from_string(stored_descriptor)
+  if M.reverse_request(stored, pressed_key, fix_key_direction) then
+    return domain.Descriptor.swap(stored)
   end
-  return domain.Descriptor.uppercase(stored)
+  return stored
 end
 
 M.resolve_primary_direction = M.primary_direction
diff --git a/tests/run.lua b/tests/run.lua
index 1609593..598ea2b 100644
--- a/tests/run.lua
+++ b/tests/run.lua
@@ -4059,6 +4059,33 @@ test("Fixed upper-case keys use the upper-case stored form", function()
   end
 end)
 
+test("Reverse-request algorithm matches every direction matrix pair", function()
+  local descriptors = { "f", "F", "t", "T" }
+  for _, fixed in ipairs({ false, true }) do
+    local pairs_checked = 0
+    for _, stored in ipairs(descriptors) do
+      for _, pressed in ipairs(descriptors) do
+        local expected
+        if fixed then
+          expected = domain.Descriptor.is_lowercase(pressed)
+              and domain.Descriptor.lowercase(stored)
+            or domain.Descriptor.uppercase(stored)
+        else
+          expected = domain.Descriptor.is_lowercase(pressed)
+              and domain.Descriptor.from_string(stored)
+            or domain.Descriptor.swap(stored)
+        end
+        local reverse = repeat_resolver.reverse_request(stored, pressed, fixed)
+        local effective = repeat_resolver.primary_direction(stored, pressed, fixed)
+        same(expected, effective, stored .. "/" .. pressed .. "/" .. tostring(fixed))
+        same(reverse, effective == domain.Descriptor.swap(stored))
+        pairs_checked = pairs_checked + 1
+      end
+    end
+    same(16, pairs_checked)
+  end
+end)
+
 for _, item in ipairs(tests) do
   local ok, failure = xpcall(item.body, debug.traceback)
   if not ok then
-- 
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