chore: update custom handler unit test to support multi line

Author: MeanderingProgrammer

Diff for: doc/render-markdown.txt

@@ -1,4 +1,4 @@
-*render-markdown.txt*          For 0.10.0         Last change: 2024 October 20
+*render-markdown.txt*          For 0.10.0         Last change: 2024 October 23
 
 ==============================================================================
 Table of Contents                          *render-markdown-table-of-contents*

Diff for: tests/custom_handler_spec.lua

@@ -25,57 +25,63 @@ end
 local function highlight_equal(root, buf)
     local marks = {}
 
-    ---@param row integer
-    ---@param start_col integer
-    ---@param end_col integer
+    ---@param row { [1]: integer, [2]: integer }
+    ---@param col { [1]: integer, [2]: integer }
     ---@param conceal? string
     ---@param hl_group? string
-    local function append(row, start_col, end_col, conceal, hl_group)
+    local function append(row, col, conceal, hl_group)
         table.insert(marks, {
-            conceal = true,
-            start_row = row,
-            start_col = start_col,
-            opts = { end_row = row, end_col = end_col, conceal = conceal, hl_group = hl_group },
+            conceal = row[1] == row[2],
+            start_row = row[1],
+            start_col = col[1],
+            opts = { end_row = row[2], end_col = col[2], conceal = conceal, hl_group = hl_group },
         })
     end
 
-    local start_row = root:range()
     local text = vim.treesitter.get_node_text(root, buf)
-    for i, line in ipairs(vim.split(text, '\n', { plain = true })) do
-        local row = start_row + i - 1
-        ---@type integer|nil
-        local position = 1
-        while position ~= nil do
-            local start_col, end_col = line:find('(=)=[^=]+=(=)', position)
-            if start_col ~= nil and end_col ~= nil then
-                -- Translate 1 based index to 0 based index, update position
-                start_col, position = start_col - 1, end_col + 1
-                -- Hide first 2 equal signs
-                append(row, start_col, start_col + 2, '', nil)
-                -- Highlight contents
-                append(row, start_col, end_col, nil, 'DiffDelete')
-                -- Hide last 2 equal signs
-                append(row, end_col - 2, end_col, '', nil)
-            else
-                position = nil
-            end
+    local top_row = root:range()
+
+    ---@param index integer
+    ---@return integer, integer
+    local function row_col(index)
+        local lines = vim.split(text:sub(1, index), '\n', { plain = true })
+        return top_row + #lines - 1, #lines[#lines]
+    end
+
+    ---@type integer|nil
+    local index = 1
+    while index ~= nil do
+        local start_index, end_index = text:find('(=)=[^=]+=(=)', index)
+        if start_index ~= nil and end_index ~= nil then
+            local start_row, start_col = row_col(start_index - 1)
+            local end_row, end_col = row_col(end_index)
+            -- Hide first 2 equal signs
+            append({ start_row, start_row }, { start_col, start_col + 2 }, '', nil)
+            -- Highlight contents
+            append({ start_row, end_row }, { start_col, end_col }, nil, 'DiffDelete')
+            -- Hide last 2 equal signs
+            append({ end_row, end_row }, { end_col - 2, end_col }, '', nil)
+            index = end_index + 1
+        else
+            index = nil
         end
     end
+
     return marks
 end
 
----@param row integer
----@param start_col integer
----@param end_col integer
----@return render.md.MarkInfo
-local function highlight(row, start_col, end_col)
+---@param row { [1]: integer, [2]: integer }
+---@param col { [1]: integer, [2]: integer }
+---@return render.md.MarkInfo[]
+local function highlight_equals(row, col)
     ---@type render.md.MarkInfo
-    return {
-        row = { row, row },
-        col = { start_col, end_col },
+    local highlight = {
+        row = row,
+        col = col,
         hl_eol = false,
         hl_group = 'DiffDelete',
     }
+    return { util.conceal(row[1], col[1], col[1] + 2), highlight, util.conceal(row[2], col[2] - 2, col[2]) }
 end
 
 describe('custom_handler.md', function()
@@ -142,7 +148,8 @@ describe('custom_handler.md', function()
             util.heading(row:get(), 1), -- Heading
             util.inline_code(row:increment(2), 0, 8), -- Inline code
             { util.conceal(row:increment(2), 0, 1), util.conceal(row:get(), 7, 8) }, -- Backslash escapes
-            { util.conceal(row:increment(2), 5, 7), highlight(row:get(), 5, 25), util.conceal(row:get(), 23, 25) }, -- Highlight equals
+            highlight_equals({ row:increment(2), row:get() }, { 5, 25 }), -- Highlight equals 1
+            highlight_equals({ row:increment(), row:increment() }, { 7, 7 }), -- Highlight equals 2
         })
 
         local actual = util.get_actual_marks()

Diff for: tests/data/custom_handler.md

@@ -5,3 +5,5 @@
 \$1.50 \$3.55
 
 Some ==highlighted text== line
+Across ==multiple
+lines== of text