feat(views): make queue view sort order configurable (#154)

Problem: the queue/priority view sort in `sort_tasks_priority()` uses a
hardcoded tiebreak chain (status, priority, due, order, id). Users who
care more about due dates than priority have no way to reorder it.

Solution: add `view.queue.sort` config field (string[]) that defines an
ordered tiebreak chain. `build_queue_comparator()` maps each key to a
comparison function and returns a single comparator. Unknown keys emit a
`log.warn`. The default matches the previous hardcoded behavior.

doc/pending.txt

@@ -542,11 +542,12 @@ Category view (default): ~                             *pending-view-category*
     `zc` and `zo`.
 
 Queue view: ~                                             *pending-view-queue*
-    A flat list of all tasks sorted by status (wip → pending → blocked →
-    done), then by priority, then by due date (tasks without a due date sort
-    last), then by internal order. Category names are shown as right-aligned virtual
-    text alongside the due date virtual text so tasks remain identifiable
-    across categories. The buffer is named `pending://queue`.
+    A flat list of all tasks sorted by a configurable tiebreak chain
+    (default: status → priority → due → order → id). See
+    `view.queue.sort` in |pending-config| for customization. Category
+    names are shown as right-aligned virtual text alongside the due date
+    virtual text so tasks remain identifiable across categories. The
+    buffer is named `pending://queue`.
 
 ==============================================================================
 FILTERS                                                       *pending-filters*
@@ -749,7 +750,9 @@ loads: >lua
           order = {},
           folding = true,
         },
-        queue = {},
+        queue = {
+          sort = { 'status', 'priority', 'due', 'order', 'id' },
+        },
       },
       keymaps = {
         close = 'q',
@@ -891,6 +894,24 @@ Fields: ~
 
                          {queue}     (table)            *pending.QueueViewConfig*
                                     Queue (priority) view settings.
+                                      {sort} (string[], default:
+                                        `{ 'status', 'priority', 'due',
+                                        'order', 'id' }`)
+                                        Ordered tiebreak chain for the
+                                        queue view sort. Each element is a
+                                        sort key; the comparator walks the
+                                        list and returns on the first
+                                        non-equal comparison. Valid keys:
+                                          `status`   wip < pending <
+                                                     blocked < done
+                                          `priority` higher number first
+                                          `due`      sooner first, no-due
+                                                     last
+                                          `order`    ascending
+                                          `id`       ascending
+                                          `age`      alias for `id`
+                                        Unknown keys are ignored with a
+                                        warning.
 
                          Examples: >lua
                              vim.g.pending = {
@@ -901,6 +922,10 @@ Fields: ~
                                    order = { 'Work', 'Personal' },
                                    folding = { foldtext = '%c: %n items' },
                                  },
+                                 queue = {
+                                   sort = { 'status', 'due', 'priority',
+                                            'order', 'id' },
+                                 },
                                },
                              }
 <

lua/pending/config.lua

@@ -87,6 +87,7 @@
 ---@field hide_done_categories? boolean
 
 ---@class pending.QueueViewConfig
+---@field sort? string[]
 
 ---@class pending.ViewConfig
 ---@field default? 'category'|'priority'
@@ -133,7 +134,9 @@ local defaults = {
       folding = true,
       hide_done_categories = false,
     },
-    queue = {},
+    queue = {
+      sort = { 'status', 'priority', 'due', 'order', 'id' },
+    },
   },
   keymaps = {
     close = 'q',

lua/pending/views.lua

@@ -106,17 +106,23 @@ local function sort_tasks(tasks)
   end)
 end
 
----@param tasks pending.Task[]
-local function sort_tasks_priority(tasks)
-  table.sort(tasks, function(a, b)
+---@type table<string, fun(a: pending.Task, b: pending.Task): boolean?>
+local sort_key_comparators = {
+  status = function(a, b)
     local ra = status_rank[a.status] or 1
     local rb = status_rank[b.status] or 1
     if ra ~= rb then
       return ra < rb
     end
+    return nil
+  end,
+  priority = function(a, b)
     if a.priority ~= b.priority then
       return a.priority > b.priority
     end
+    return nil
+  end,
+  due = function(a, b)
     local a_due = a.due or ''
     local b_due = b.due or ''
     if a_due ~= b_due then
@@ -128,11 +134,56 @@ local function sort_tasks_priority(tasks)
       end
       return a_due < b_due
     end
+    return nil
+  end,
+  order = function(a, b)
     if a.order ~= b.order then
       return a.order < b.order
     end
-    return a.id < b.id
-  end)
+    return nil
+  end,
+  id = function(a, b)
+    if a.id ~= b.id then
+      return a.id < b.id
+    end
+    return nil
+  end,
+  age = function(a, b)
+    if a.id ~= b.id then
+      return a.id < b.id
+    end
+    return nil
+  end,
+}
+
+---@return fun(a: pending.Task, b: pending.Task): boolean
+local function build_queue_comparator()
+  local log = require('pending.log')
+  local keys = config.get().view.queue.sort or { 'status', 'priority', 'due', 'order', 'id' }
+  local comparators = {}
+  for _, key in ipairs(keys) do
+    local cmp = sort_key_comparators[key]
+    if cmp then
+      table.insert(comparators, cmp)
+    else
+      log.warn('unknown queue sort key: ' .. key)
+    end
+  end
+  return function(a, b)
+    for _, cmp in ipairs(comparators) do
+      local result = cmp(a, b)
+      if result ~= nil then
+        return result
+      end
+    end
+    return false
+  end
+end
+
+---@param tasks pending.Task[]
+local function sort_tasks_priority(tasks)
+  local cmp = build_queue_comparator()
+  table.sort(tasks, cmp)
 end
 
 ---@param tasks pending.Task[]

spec/views_spec.lua

@@ -529,5 +529,83 @@ describe('views', function()
       end
       assert.is_nil(task_meta.recur)
     end)
+
+    it('sorts by due before priority when sort config is reordered', function()
+      vim.g.pending = {
+        data_path = tmpdir .. '/tasks.json',
+        view = { queue = { sort = { 'status', 'due', 'priority', 'order', 'id' } } },
+      }
+      config.reset()
+      s:add({ description = 'High no due', category = 'Work', priority = 2 })
+      s:add({ description = 'Low with due', category = 'Work', priority = 0, due = '2050-01-01' })
+      local lines, meta = views.priority_view(s:active_tasks())
+      local due_row, nodue_row
+      for i, m in ipairs(meta) do
+        if m.type == 'task' then
+          if lines[i]:find('Low with due') then
+            due_row = i
+          elseif lines[i]:find('High no due') then
+            nodue_row = i
+          end
+        end
+      end
+      assert.is_true(due_row < nodue_row)
+    end)
+
+    it('uses default sort when config sort is nil', function()
+      vim.g.pending = {
+        data_path = tmpdir .. '/tasks.json',
+        view = { queue = {} },
+      }
+      config.reset()
+      s:add({ description = 'Low', category = 'Work', priority = 0 })
+      s:add({ description = 'High', category = 'Work', priority = 1 })
+      local lines, meta = views.priority_view(s:active_tasks())
+      local high_row, low_row
+      for i, m in ipairs(meta) do
+        if m.type == 'task' then
+          if lines[i]:find('High') then
+            high_row = i
+          elseif lines[i]:find('Low') then
+            low_row = i
+          end
+        end
+      end
+      assert.is_true(high_row < low_row)
+    end)
+
+    it('ignores unknown sort keys with a warning', function()
+      vim.g.pending = {
+        data_path = tmpdir .. '/tasks.json',
+        view = { queue = { sort = { 'bogus', 'status', 'id' } } },
+      }
+      config.reset()
+      s:add({ description = 'A', category = 'Work' })
+      s:add({ description = 'B', category = 'Work' })
+      local lines = views.priority_view(s:active_tasks())
+      assert.is_true(#lines == 2)
+    end)
+
+    it('supports age sort key as alias for id', function()
+      vim.g.pending = {
+        data_path = tmpdir .. '/tasks.json',
+        view = { queue = { sort = { 'age' } } },
+      }
+      config.reset()
+      s:add({ description = 'Older', category = 'Work' })
+      s:add({ description = 'Newer', category = 'Work' })
+      local lines, meta = views.priority_view(s:active_tasks())
+      local older_row, newer_row
+      for i, m in ipairs(meta) do
+        if m.type == 'task' then
+          if lines[i]:find('Older') then
+            older_row = i
+          elseif lines[i]:find('Newer') then
+            newer_row = i
+          end
+        end
+      end
+      assert.is_true(older_row < newer_row)
+    end)
   end)
 end)