feat(duplicates): only treat as duplicate if in the same group (#750)

doc/bufferline.txt

@@ -150,6 +150,7 @@ The available configuration are:
             show_close_icon = true | false,
             show_tab_indicators = true | false,
             show_duplicate_prefix = true | false, -- whether to show duplicate buffer prefix
+            duplicates_across_groups = true, -- whether to consider duplicate paths in different groups as duplicates
             persist_buffer_sort = true, -- whether or not custom sorted buffers should persist
             move_wraps_at_ends = false, -- whether or not the move command "wraps" at the first or last position
             -- can also be a table containing 2 custom separators

lua/bufferline/config.lua

@@ -646,6 +646,7 @@ local function get_defaults()
     show_close_icon = true,
     show_tab_indicators = true,
     show_duplicate_prefix = true,
+    duplicates_across_groups = true,
     enforce_regular_tabs = false,
     always_show_bufferline = true,
     persist_buffer_sort = true,

lua/bufferline/duplicates.lua

@@ -22,6 +22,8 @@ end
 ---@param elements bufferline.TabElement[]
 ---@return bufferline.TabElement[]
 function M.mark(elements)
+  local options = config.options
+  local duplicates_across_groups = options.duplicates_across_groups
   return utils.map(function(current)
     if current.path == "" then return current end
     local duplicate = duplicates[current.name]
@@ -30,6 +32,9 @@ function M.mark(elements)
     else
       local depth, limit, is_same_buffer = 1, 10, false
       for _, element in ipairs(duplicate) do
+        if (duplicates_across_groups == false) and (current.group ~= element.group) then
+          return current
+        end
         local element_depth = 1
         is_same_buffer = current.path == element.path
         while is_same_path(current.path, element.path, element_depth) and not is_same_buffer do

lua/bufferline/types.lua

@@ -51,6 +51,7 @@
 ---@field public show_close_icon? boolean
 ---@field public show_tab_indicators? boolean
 ---@field public show_duplicate_prefix? boolean
+---@field public duplicates_across_groups? boolean
 ---@field public enforce_regular_tabs? boolean
 ---@field public always_show_bufferline? boolean
 ---@field public persist_buffer_sort? boolean

tests/duplicates_spec.lua

@@ -11,6 +11,8 @@ describe("Duplicate Tests - ", function()
   end)
 
   it("should mark duplicate files", function()
+    config.setup({})
+    config.apply()
     local result = duplicates.mark({
       {
         path = "/test/dir_a/dir_b/file.txt",
@@ -34,6 +36,62 @@ describe("Duplicate Tests - ", function()
     assert.is_equal(#result, 3)
   end)
 
+  it("should show duplicates across groups", function()
+    config.setup({ options = { duplicates_across_groups = true } })
+    config.apply()
+    local result = duplicates.mark({
+      {
+        path = "/test/dir_a/dir_b/file.txt",
+        name = "file.txt",
+        ordinal = 1,
+        group = "A",
+      },
+      {
+        path = "/test/dir_a/dir_c/file.txt",
+        name = "file.txt",
+        ordinal = 2,
+        group = "A",
+      },
+      {
+        path = "/test/dir_a/dir_d/file.txt",
+        name = "file.txt",
+        ordinal = 1,
+        group = "B",
+      },
+    })
+    assert.is_equal(result[1].duplicated, "path")
+    assert.is_equal(result[2].duplicated, "path")
+    assert.is_equal(result[3].duplicated, "path")
+  end)
+
+  it("should not show duplicates across groups", function()
+    config.setup({ options = { duplicates_across_groups = false } })
+    config.apply()
+    local result = duplicates.mark({
+      {
+        path = "/test/dir_a/dir_b/file.txt",
+        name = "file.txt",
+        ordinal = 1,
+        group = "A",
+      },
+      {
+        path = "/test/dir_a/dir_c/file.txt",
+        name = "file.txt",
+        ordinal = 2,
+        group = "A",
+      },
+      {
+        path = "/test/dir_a/dir_d/file.txt",
+        name = "file.txt",
+        ordinal = 1,
+        group = "B",
+      },
+    })
+    assert.is_equal(result[1].duplicated, "path")
+    assert.is_equal(result[2].duplicated, "path")
+    assert.falsy(result[3].duplicated)
+  end)
+
   it("should return the correct prefix count", function()
     local result = duplicates.mark({
       {