From bc17b1a4318ac5de88c2024eb48252a5da14799c Mon Sep 17 00:00:00 2001
From: Matěj Cepl <mcepl@cepl.eu>
Date: Fri, 17 Mar 2023 16:03:41 +0100
Subject: Move countLines to hunk as well.

---
 ftplugin/diff_navigator.lua | 29 ++++-------------------------
 ftplugin/hunk.lua           | 24 ++++++++++++++++++++++++
 ftplugin/hunk_spec.lua      |  8 ++++++++
 3 files changed, 36 insertions(+), 25 deletions(-)

diff --git a/ftplugin/diff_navigator.lua b/ftplugin/diff_navigator.lua
index f2b5e0d..c36cfab 100644
--- a/ftplugin/diff_navigator.lua
+++ b/ftplugin/diff_navigator.lua
@@ -96,27 +96,6 @@ function getCurrentHunkHeader()
     return hnk.Header.parse(vim.fn.getline(lineno), lineno)
 end
 
--- Return number of lines in the range between start and end line (both
--- inclusive) which are from the state before patch and the one after
--- patch is applied.
-function countLines(start, endline)
-    local context_lines = 0
-    local old_lines = 0
-    local new_lines = 0
-
-    for line in pairs(vim.fn.getline(start, endline)) do
-        local first_char = vim.fn.strpart(line, 0, 1)
-        if first_char == ' ' then
-            local context_lines = context_lines + 1
-        elseif first_char == '-' then
-            local old_lines = old_lines + 1
-        elseif first_char == '+' then
-            local new_lines = new_lines + 1
-        end
-    end
-
-    return {context_lines + old_lines, context_lines + new_lines}
-end
 
 -- -------------------------------------------------------------
 
@@ -189,8 +168,8 @@ function DiffSplitHunk()
     --
     --
     -- Start line below header and stop one line above the current line
-    local diff_lines = countLines(old_cur_header['line'] + 1,
-        cur_line_no - 1)
+    local diff_lines = hnk.countLines(old_cur_header['line'] + 1,
+        cur_line_no - 1, vim.fn.getline)
     local diff_old = diff_lines[1]
     local diff_new = diff_lines[2]
 
@@ -251,8 +230,8 @@ function DiffDeleteHunk()
         vim.cmd("normal " .. start_hunk_line .. ",$" .. "d")
     -- we are in the middle of the file ... it's a bit more complicated
     else
-        local count_lines = countLines(start_hunk_line + 1,
-            next_hunk_line - 1)
+        local count_lines = hnk.countLines(start_hunk_line + 1,
+            next_hunk_line - 1, vim.fn.getline)
         local added_lines = count_lines[2] - count_lines[1]
         vim.fn.setpos(".", {0, next_hunk_line, 1, 0})
         vim.cmd("normal " .. start_hunk_line .. "," .. (next_hunk_line - 1) .. "d")
diff --git a/ftplugin/hunk.lua b/ftplugin/hunk.lua
index c01e0a9..db8ac06 100644
--- a/ftplugin/hunk.lua
+++ b/ftplugin/hunk.lua
@@ -26,9 +26,33 @@ function M.Header:parse(inline, lineNo)
 end
 
 -- Generate hunk header line
+-- TODO some protection against bad parameters (creating impossible regions of lines)
+-- TODO return empty string in such case
 function M.createHunkHeader(oldStart, oldLen, newStart, newLen, remaind)
     return "@@ -" .. oldStart .. "," .. oldLen ..
         " +" .. newStart .. "," .. newLen .. " @@ " .. remaind
 end
 
+-- Return number of lines in the range between start and end line (both
+-- inclusive) which are from the state before patch and the one after
+-- patch is applied.
+function M.countLines(start, endline, getlfn)
+    local context_lines = 0
+    local old_lines = 0
+    local new_lines = 0
+
+    for line in pairs(getlfn(start, endline)) do
+        local first_char = line:sub(1, 1)
+        if first_char == ' ' then
+            local context_lines = context_lines + 1
+        elseif first_char == '-' then
+            local old_lines = old_lines + 1
+        elseif first_char == '+' then
+            local new_lines = new_lines + 1
+        end
+    end
+
+    return {context_lines + old_lines, context_lines + new_lines}
+end
+
 return M
diff --git a/ftplugin/hunk_spec.lua b/ftplugin/hunk_spec.lua
index c640afb..13d14f3 100644
--- a/ftplugin/hunk_spec.lua
+++ b/ftplugin/hunk_spec.lua
@@ -38,9 +38,17 @@ describe("Class functions", function()
         hk = require("hunk")
     end)
 
+-- TODO some protection of hk.createHunkHeader() against bad
+-- TODO parameters (creating impossible regions of lines) return
+-- TODO empty string in such case
     it("generates correct header", function()
         local header_str = hk.createHunkHeader(12,15,25,30,"something")
         local exp_str = "@@ -12,15 +25,30 @@ something"
         assert.are.equal(exp_str, header_str)
     end)
+
+    it("counts lines in chunk correctly", function()
+        local header_str = hk.countLines(12,15, function(beg, fin) return {} end)
+        pending("This test is pending ...")
+    end)
 end)
-- 
cgit