fix: block content alignment (#698)

* fix(indent): do not modify block indents if one line is correct

Previously, if a single line was correctly aligned with a block, but the
others were overindented it was possible for the overindented lines to
be unindented. This is not correct.

The overindented lines shouldn't shift at all if at least one of the
lines is correctly indented. This is to preserve manual formatting.

This commit ensures the above functionality.

* fix(indent): ignore blank lines for block content indentation

lua/orgmode/org/indent.lua

@@ -175,27 +175,34 @@ local get_matches = ts_utils.memoize_by_buf_tick(function(bufnr)
         indent = new_header_indent,
       })
 
-      local content_indent_pad = 0
+      local content_indent_pad
       -- Only include the header line and the content. Do not include the footer in the loop.
       for i = range.start.line + 1, range['end'].line - 2 do
-        local curr_indent = vim.fn.indent(i + 1)
-        -- Correctly align the pad to the new header position if it was underindented
-        local new_indent_pad = new_header_indent - curr_indent
-        -- If the current content indentaion is less than the new header indent we want to increase all of the
-        -- content by the largest difference in indentation between a given content line and the new header indent.
-        if curr_indent < new_header_indent then
-          content_indent_pad = math.max(new_indent_pad, content_indent_pad)
-        else
-          -- If the current content indentation is more than the new header indentation, but it was the current
-          -- content indentation was less than the current header indent then we want to add some indentation onto
-          -- the content by the largest negative difference (meaning -1 > -2 > -3 so take -1 as the pad).
-          --
-          -- We do a check for 0 here as we don't want to do a max of neg number against 0. 0 will always win. As
-          -- such if the current pad is 0 just set to the new calculated pad.
-          if content_indent_pad == 0 then
-            content_indent_pad = new_indent_pad
+        local linenr = i + 1
+        local line_content = vim.api.nvim_buf_get_lines(bufnr, linenr - 1, linenr, true)[1]
+        -- If the line is blank, we should ignore it as `vim.fn.indent` will return a 0 indent for
+        -- it which may be less indented than the header indentation. We shouldn't factor in blank
+        -- lines for indentation.
+        if not line_content:match('^$') then
+          local curr_indent = vim.fn.indent(linenr)
+          -- Correctly align the pad to the new header position if it was underindented
+          local new_indent_pad = new_header_indent - curr_indent
+          -- If the current content indentaion is less than the new header indent we want to increase all of the
+          -- content by the largest difference in indentation between a given content line and the new header indent.
+          if curr_indent < new_header_indent then
+            content_indent_pad = math.max(new_indent_pad, content_indent_pad or 0)
           else
-            content_indent_pad = math.max(new_indent_pad, content_indent_pad)
+            -- If the current content indentation is more than the new header indentation, but it was the current
+            -- content indentation was less than the current header indent then we want to add some indentation onto
+            -- the content by the largest negative difference (meaning -1 > -2 > -3 so take -1 as the pad).
+            --
+            -- We do a check for 0 here as we don't want to do a max of neg number against 0. 0 will always win. As
+            -- such if the current pad is 0 just set to the new calculated pad.
+            if not content_indent_pad then
+              content_indent_pad = new_indent_pad
+            else
+              content_indent_pad = math.max(new_indent_pad, content_indent_pad)
+            end
           end
         end
       end

tests/plenary/org/indent_spec.lua

@@ -62,6 +62,23 @@ local function test_full_reindent()
     '           "another key": "another value"',
     '         }',
     '         #+END_SRC',
+    '    - Correctly maintains indentation when single line is at the same level as header and rest is overindented',
+    '      #+BEGIN_SRC json',
+    '      {',
+    '           "key": "value",',
+    '           "another key": "another value"',
+    '               }',
+    '      #+END_SRC',
+    '    - Correctly ignores blank lines for calculating indentation',
+    '      #+BEGIN_SRC json',
+    '',
+    '          {',
+    '            "key": "value",',
+    '',
+    '            "another key": "another value"',
+    '          }',
+    '',
+    '      #+END_SRC',
   }
   helpers.create_file(unformatted_file)
   vim.cmd([[silent norm 0gg=G]])
@@ -118,6 +135,23 @@ local function test_full_reindent()
       '        "another key": "another value"',
       '      }',
       '      #+END_SRC',
+      '    - Correctly maintains indentation when single line is at the same level as header and rest is overindented',
+      '      #+BEGIN_SRC json',
+      '      {',
+      '           "key": "value",',
+      '           "another key": "another value"',
+      '               }',
+      '      #+END_SRC',
+      '    - Correctly ignores blank lines for calculating indentation',
+      '      #+BEGIN_SRC json',
+      '',
+      '      {',
+      '        "key": "value",',
+      '',
+      '        "another key": "another value"',
+      '      }',
+      '',
+      '      #+END_SRC',
     }
   else
     expected = {
@@ -171,6 +205,23 @@ local function test_full_reindent()
       '    "another key": "another value"',
       '  }',
       '  #+END_SRC',
+      '- Correctly maintains indentation when single line is at the same level as header and rest is overindented',
+      '  #+BEGIN_SRC json',
+      '  {',
+      '       "key": "value",',
+      '       "another key": "another value"',
+      '           }',
+      '  #+END_SRC',
+      '- Correctly ignores blank lines for calculating indentation',
+      '  #+BEGIN_SRC json',
+      '',
+      '  {',
+      '    "key": "value",',
+      '',
+      '    "another key": "another value"',
+      '  }',
+      '',
+      '  #+END_SRC',
     }
   end
   expect_whole_buffer(expected)