First working version of hunk module.

Parsing works, module function createHunkHeader works as well,
and both tested on the good path.

3 files changed, 108 insertions, 52 deletions

diff --git a/ftplugin/diff_navigator.lua.new b/ftplugin/diff_navigator.lua
index 96f09da..f2b5e0d 100644
--- a/ftplugin/diff_navigator.lua.new
+++ b/ftplugin/diff_navigator.lua
@@ -64,6 +64,8 @@ local function checkFilterDiff()
     return true
 end
 
+local hnk = require('hunk')
+
 -- Given the linenumber of the hunk returned its parsed content
 --
 -- From http://www.clearchain.com/blog/posts/splitting-a-patch
@@ -78,24 +80,6 @@ end
 --         hunk (this includes lines marked with "-")
 --     the third number is the starting line for this hunk in newfile
 --     the last number is the number of lines after the hunk has been applied.
-function parseHunkHeader(lineno)
-    local inline = vim.fn.getline(lineno)
-    -- Thanks to somian from #vim IRC channel for this incredible RE
-    local hunk_nos = vim.fn.substitute(inline,
-         '\\_^\\S\\S\\s\\+-\\(\\d\\+\\),\\(\\d\\+\\)\\s\\++\\(\\d\\+\\),\\(\\d\\+\\)\\s\\+\\S\\S\\(\\_.*\\)',
-         "\\\\1,\\\\2,\\\\3,\\\\4,\\\\5","")
-    local result = hunk_nos:split(",")
-
-    return {
-        ['line'] = lineno,
-        ['oldFirst'] = result[1],
-        ['oldCount'] = result[2],
-        ['newFirst'] = result[3],
-        ['newCount'] = result[4],
-        ['remainderLine'] = table.concat(result, ",", 5)
-    }
-end
-
 -- vim.api.nvim_eval('"README.md" =~ glob2regpat("/home/nvim/*.md")') ~= 0 
 -- is equivalent of
 -- "README.md" =~ glob2regpat("/home/nvim/*.md")
@@ -109,13 +93,7 @@ function getCurrentHunkHeader()
         lineno = vim.fn.search('^@@[ +-\\,\\d]*@@.*$', 'bncW')
     end
 
-    return parseHunkHeader(lineno)
-end
-
--- Generate hunk header line
-function createHunkHeader(oldStart, oldLen, newStart, newLen, remaind)
-    return "@@ -" .. oldStart .. "," .. oldLen ..
-        " +" .. newStart .. "," .. newLen .. " @@" .. remaind
+    return hnk.Header.parse(vim.fn.getline(lineno), lineno)
 end
 
 -- Return number of lines in the range between start and end line (both
@@ -156,9 +134,7 @@ function DiffShowHunk()
     -- if the current line begins with '+++' or '---', then it makes
     -- sense to search forwards
     local hunk_header = getCurrentHunkHeader()
-    local hunk_annotation = vim.fn.substitute(vim.fn.getline(hunk_header['line']),
-        '^@@[ +-\\,\\d]*@@\\s*\\(.*\\)$', '\\1', '')
-    print(hunk_annotation)
+    print(hunk_header.remainderLine)
 end
 
 -- Skip to next hunk
@@ -228,7 +204,7 @@ function DiffSplitHunk()
     local new_start_del_len = diff_old
     local new_start_add_start = old_cur_header['newFirst']
     local new_start_add_len = diff_new
-    vim.fn.setreg('x', createHunkHeader(new_start_del_start, new_start_del_len,
+    vim.fn.setreg('x', hnk.createHunkHeader(new_start_del_start, new_start_del_len,
         new_start_add_start, new_start_add_len,
         old_cur_header['remainderLine']))
     local window_state = vim.cmd.winsaveview()
@@ -244,7 +220,7 @@ function DiffSplitHunk()
     local new_pos_del_len = old_cur_header['oldCount'] - diff_old
     local new_pos_add_start = old_cur_header['newFirst'] + diff_new
     local new_pos_add_len = old_cur_header['newCount'] - diff_new
-    vim.fn.setreg('x', createHunkHeader(new_pos_del_start, new_pos_del_len,
+    vim.fn.setreg('x', hnk.createHunkHeader(new_pos_del_start, new_pos_del_len,
         new_pos_add_start, new_pos_add_len, ""))
     vim.cmd('normal! O<Esc>\"xP')
 end
@@ -286,7 +262,7 @@ function DiffDeleteHunk()
 
         -- recalculate current hunk header
         while (not last_hunk_in_file) do
-            local cur_header = parseHunkHeader(vim.fn.line("."))
+            local cur_header = hnk.parse(vim.fn.line("."))
             local old_line = cur_header['newFirst']
             local new_line = old_line - added_lines
             vim.fn.setreg('x', vim.fn.substitute(vim.fn.getline("."), "+" .. old_line .. ",",
@@ -307,25 +283,25 @@ function DiffDeleteHunk()
         vim.fn.setpos(".", {0, new_header_line, 1, 0})
     end
 end
-
--- -- Define new commands
-vim.cmd('command DiffAnnotate    DiffAnnotate()')
-vim.cmd('command DiffShowHunk    DiffShowHunk()')
-vim.cmd('command DiffNextHunk    DiffNextHunk()')
-vim.cmd('command DiffPrevHunk    DiffPrevHunk()')
-vim.cmd('command DiffNextFile    DiffNextFile()')
-vim.cmd('command DiffPrevFile    DiffPrevFile()')
-vim.cmd('command DiffSplitHunk   DiffSplitHunk()')
-vim.cmd('command DiffDeleteHunk  DiffDeleteHunk()')
 -- 
-
--- Default },{,(,) do not make much sense in diffs, so remap them to
--- make something useful
-vim.keymap.set('n', '<Leader>ex3', vim.treesitter.start)
-vim.keymap.set('n', '}', DiffNextFile)
-vim.keymap.set('n', '{', DiffPrevFile)
-vim.keymap.set('n', ')', DiffNextHunk)
-vim.keymap.set('n', '(', DiffPrevHunk)
-vim.keymap.set('n', '!', DiffShowHunk)
-vim.keymap.set('n', '<leader>s', DiffSplitHunk)
-vim.keymap.set('n', '<leader>s', DiffDeleteHunk)
+-- -- -- Define new commands
+-- vim.cmd('command DiffAnnotate    DiffAnnotate()')
+-- vim.cmd('command DiffShowHunk    DiffShowHunk()')
+-- vim.cmd('command DiffNextHunk    DiffNextHunk()')
+-- vim.cmd('command DiffPrevHunk    DiffPrevHunk()')
+-- vim.cmd('command DiffNextFile    DiffNextFile()')
+-- vim.cmd('command DiffPrevFile    DiffPrevFile()')
+-- vim.cmd('command DiffSplitHunk   DiffSplitHunk()')
+-- vim.cmd('command DiffDeleteHunk  DiffDeleteHunk()')
+-- -- 
+-- 
+-- -- Default },{,(,) do not make much sense in diffs, so remap them to
+-- -- make something useful
+-- vim.keymap.set('n', '<Leader>ex3', vim.treesitter.start)
+-- vim.keymap.set('n', '}', DiffNextFile)
+-- vim.keymap.set('n', '{', DiffPrevFile)
+-- vim.keymap.set('n', ')', DiffNextHunk)
+-- vim.keymap.set('n', '(', DiffPrevHunk)
+-- vim.keymap.set('n', '!', DiffShowHunk)
+-- vim.keymap.set('n', '<leader>s', DiffSplitHunk)
+-- vim.keymap.set('n', '<leader>s', DiffDeleteHunk)
diff --git a/ftplugin/hunk.lua b/ftplugin/hunk.lua
new file mode 100644
index 0000000..c01e0a9
--- /dev/null
+++ b/ftplugin/hunk.lua
@@ -0,0 +1,34 @@
+-- TODO:         show current hunk in status line
+-- TODO:         incorporate more patchutils functionality
+
+-- FIXME https://www.reddit.com/r/neovim/comments/unwvkw/github_hkuptyrunesnvim_lua_test_framework_for/
+-- FIXME https://github.com/hkupty/runes.nvim
+
+pretty = require("pl.pretty")
+
+local M = {}
+
+-- Header object
+M.Header = {}
+
+function M.Header:parse(inline, lineNo)
+    local pat = "@@%s+%-(%d+),(%d+)%s+%+(%d+),(%d+)%s+@@%s*(.*)"
+    local of, oc, nf, nc, rem = inline:match(pat)
+
+    return {
+        line = lineNo,
+        oldFirst = tonumber(of),
+        oldCount = tonumber(oc),
+        newFirst = tonumber(nf),
+        newCount = tonumber(nc),
+        remainderLine = rem
+    }
+end
+
+-- Generate hunk header line
+function M.createHunkHeader(oldStart, oldLen, newStart, newLen, remaind)
+    return "@@ -" .. oldStart .. "," .. oldLen ..
+        " +" .. newStart .. "," .. newLen .. " @@ " .. remaind
+end
+
+return M
diff --git a/ftplugin/hunk_spec.lua b/ftplugin/hunk_spec.lua
new file mode 100644
index 0000000..c640afb
--- /dev/null
+++ b/ftplugin/hunk_spec.lua
@@ -0,0 +1,46 @@
+describe("Parsing of a hunk header", function()
+    local hk, header, test_header
+
+    setup(function()
+        hk = require("hunk")
+        test_header = "@@ -20,8 +20,17 @@ Hunk #1, a/tests/test_ec_curves.py"
+    end)
+
+    before_each(function()
+        header = hk.Header:parse(test_header)
+    end)
+
+    it("it is not nil", function()
+        assert.is_not_nil(header)
+    end)
+
+    it("original line number is preserved in the attribute line", function()
+        -- not relevant here, because parse() method was run without line#
+        assert.is_nil(header.line)
+    end)
+
+    it("attributes are set correctly", function()
+        assert.are.equal(20, header.oldFirst)
+        assert.are.equal(8, header.oldCount)
+        assert.are.equal(20, header.newFirst)
+        assert.are.equal(17, header.newCount)
+    end)
+
+    it("remainder of the line is preserved as well", function()
+        assert.are.equal("Hunk #1, a/tests/test_ec_curves.py", header.remainderLine)
+    end)
+end)
+
+describe("Class functions", function()
+    local hk, header, test_header
+
+    setup(function()
+        hk = require("hunk")
+    end)
+
+    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)
+end)