feat(gitgraph): use branch highlights for commit hashes

README.md

@@ -136,13 +136,22 @@ For example, use **kitty** branch symbols [more detail](https://github.com/kovid
   - 'GitGraphTimestamp'
   - 'GitGraphAuthor'
   - 'GitGraphBranchName'
+  - 'GitGraphHead'
   - 'GitGraphBranchTag'
   - 'GitGraphBranchMsg'
 
+Commit hashes use the same branch highlight group as the commit lane when available. `GitGraphHash` remains as the fallback highlight group.
+`HEAD -> branch_name` uses `GitGraphHead`, which defaults to Tokyo Night style red.
+
 ## branch colors
 
   - 'GitGraphBranch1'
   - 'GitGraphBranch2'
   - 'GitGraphBranch3'
   - 'GitGraphBranch4'
   - 'GitGraphBranch5'
+  - 'GitGraphBranch6'
+  - 'GitGraphBranch7'
+  - 'GitGraphBranch8'
+  - 'GitGraphBranch9'
+  - 'GitGraphBranch10'

lua/gitgraph/core.lua

@@ -467,6 +467,29 @@ local function graph_to_lines(options, graph, sym, fields, commits)
   ---@type I.Highlight[]
   local highlights = {}
 
+  ---@param col integer
+  ---@return string
+  local function branch_hg_for_col(col)
+    return 'GitGraphBranch' .. tostring(col % NUM_BRANCH_COLORS + 1)
+  end
+
+  ---@param row I.Row
+  ---@param commit_hash string
+  ---@return string?
+  local function branch_hg_for_commit(row, commit_hash)
+    for col, cell in ipairs(row.cells) do
+      if cell.commit and cell.commit.hash == commit_hash then
+        return branch_hg_for_col(col)
+      end
+    end
+  end
+
+  ---@param branch_names string
+  ---@return integer?, integer?
+  local function find_head_ref_range(branch_names)
+    return branch_names:find('HEAD %-> [^|%)]+')
+  end
+
   ---@param cell I.Cell
   ---@return string
   local function commit_cell_symb(cell)
@@ -519,7 +542,7 @@ local function graph_to_lines(options, graph, sym, fields, commits)
       offset = offset + width
 
       if cell.commit then
-        local hg = 'GitGraphBranch' .. tostring(j % NUM_BRANCH_COLORS + 1)
+        local hg = branch_hg_for_col(j)
         row_hls[#row_hls + 1] = { hg = hg, row = row_idx, start = start, stop = stop }
       elseif cell.symbol == sym.GHOR then
         -- take color from first right cell that attaches to this connector
@@ -530,7 +553,7 @@ local function graph_to_lines(options, graph, sym, fields, commits)
           --       to figure out where our vertical branch is
 
           if rcell.commit and vim.tbl_contains(continuation_symbols, rcell.symbol) then
-            local hg = 'GitGraphBranch' .. tostring(k % NUM_BRANCH_COLORS + 1)
+            local hg = branch_hg_for_col(k)
             row_hls[#row_hls + 1] = { hg = hg, row = row_idx, start = start, stop = stop }
             break
           end
@@ -632,6 +655,7 @@ local function graph_to_lines(options, graph, sym, fields, commits)
         local hash = c.hash:sub(1, 7)
         local timestamp = c.author_date
         local author = c.author_name
+        local hash_hg = branch_hg_for_commit(proper_row, c.hash) or ITEM_HGS.hash.name
 
         local branch_names = #c.branch_names > 0 and ('(%s)'):format(table.concat(c.branch_names, ' | ')) or nil
 
@@ -669,12 +693,26 @@ local function graph_to_lines(options, graph, sym, fields, commits)
         for _, name in ipairs(fields) do
           local value = items[name]
           if value then
+            local start = offset
             highlights[#highlights + 1] = {
-              hg = ITEM_HGS[name].name,
+              hg = name == 'hash' and hash_hg or ITEM_HGS[name].name,
               row = idx,
-              start = offset,
-              stop = offset + #value,
+              start = start,
+              stop = start + #value,
             }
+
+            if name == 'branch_name' then
+              local head_start, head_stop = find_head_ref_range(value)
+              if head_start and head_stop then
+                highlights[#highlights + 1] = {
+                  hg = ITEM_HGS.head.name,
+                  row = idx,
+                  start = start + head_start - 1,
+                  stop = start + head_stop,
+                }
+              end
+            end
+
             add_to_row(value)
           end
         end

lua/gitgraph/highlights.lua

@@ -10,6 +10,7 @@ M.ITEM_HGS = {
   timestamp = { name = 'GitGraphTimestamp', fg = '#98971a' },
   author = { name = 'GitGraphAuthor', fg = '#458588' },
   branch_name = { name = 'GitGraphBranchName', fg = '#d5651c' },
+  head = { name = 'GitGraphHead', fg = '#f7768e' },
   tag = { name = 'GitGraphBranchTag', fg = '#d79921' },
   message = { name = 'GitGraphBranchMsg', fg = '#339921' },
 }
@@ -21,6 +22,11 @@ M.BRANCH_HGS = {
   { name = 'GitGraphBranch3', fg = '#d79921' },
   { name = 'GitGraphBranch4', fg = '#98971a' },
   { name = 'GitGraphBranch5', fg = '#d5651c' },
+  { name = 'GitGraphBranch6', fg = '#689d6a' },
+  { name = 'GitGraphBranch7', fg = '#cc241d' },
+  { name = 'GitGraphBranch8', fg = '#83a598' },
+  { name = 'GitGraphBranch9', fg = '#8ec07c' },
+  { name = 'GitGraphBranch10', fg = '#fabd2f' },
 }
 
 --- sets highlight groups if they are missing