Fix edge cases with python string splitting

Author: AndrewRadev

autoload/sj/python.vim

@@ -341,11 +341,47 @@ function! sj#python#SplitString()
   let body      = string[1:-2]
   let indent    = indent(lineno)
 
-  if body =~ '^\(''\|""\)'
-    " then we're trying to split a string that's already multiline, ignore:
+  if body =~ '^[''"]$'
+    " our body is a single quote, we're trying to split a triple-quoted string
     return 0
   endif
 
+  if body =~ '^\(''''\s*''''\|""\s*""\)$'
+    if search('\(''''\zs\s*''''\|""\zs\s*""\)', 'W', line('.')) <= 0
+      return 0
+    endif
+
+    if delimiter == '"'
+      call sj#ReplaceMotion('va"', "\"\n\"")
+    elseif delimiter == "'"
+      call sj#ReplaceMotion("va'", "'\n'")
+    else
+      return 0
+    endif
+
+    return 1
+  endif
+
+  if body =~ '^\(''''\|""\)\S'
+    " then the string is already triple-quoted, just replace the insides
+    if search('\(''''\|""\)\zs\S', 'W', line('.')) <= 0
+      return 0
+    endif
+
+    if delimiter == '"'
+      let inner_body = sj#GetMotion('vi"')
+      call sj#ReplaceMotion('vi"', "\n"..inner_body.."\n")
+    elseif delimiter == "'"
+      let inner_body = sj#GetMotion("vi'")
+      call sj#ReplaceMotion("vi'", "\n"..inner_body.."\n")
+    else
+      return 0
+    endif
+
+    call sj#SetIndent(lineno + 1, lineno + 1, indent + shiftwidth())
+    return 1
+  endif
+
   if delimiter == '"'
     if len(body) == 0
       call sj#ReplaceMotion('vi"', '"""'.."\n"..'"""')

ftplugin/htmldjango/splitjoin.vim

@@ -2,12 +2,14 @@
 
 if !exists('b:splitjoin_split_callbacks')
   let b:splitjoin_split_callbacks = [
-        \ 'sj#html#SplitTags'
+        \ 'sj#html#SplitTags',
+        \ 'sj#html#SplitAttributes'
         \ ]
 endif
 
 if !exists('b:splitjoin_join_callbacks')
   let b:splitjoin_join_callbacks = [
+        \ 'sj#html#JoinAttributes',
         \ 'sj#html#JoinTags'
         \ ]
 endif

spec/plugin/python_spec.rb

@@ -303,6 +303,98 @@ def example():
       EOF
     end
 
+    it "splits single-line \"\"\" strings" do
+      set_file_contents <<~EOF
+        string = """something, 'anything'"""
+      EOF
+
+      vim.search '"""'
+      split
+
+      assert_file_contents <<~EOF
+        string = """
+            something, 'anything'
+        """
+      EOF
+    end
+
+    it "splits single-line ''' strings" do
+      set_file_contents <<~EOF
+        string = '''something, "anything"'''
+      EOF
+
+      vim.search "'''"
+      split
+
+      assert_file_contents <<~EOF
+        string = '''
+            something, "anything"
+        '''
+      EOF
+    end
+
+    it "splits empty single-line ''' strings" do
+      set_file_contents <<~EOF
+        string = ''' '''
+      EOF
+
+      vim.search "'''"
+      split
+
+      assert_file_contents <<~EOF
+        string = '''
+        '''
+      EOF
+    end
+
+    it "splits empty single-line \"\"\" strings" do
+      set_file_contents <<~EOF
+        string = """ """
+      EOF
+
+      vim.search '"""'
+      split
+
+      assert_file_contents <<~EOF
+        string = """
+        """
+      EOF
+    end
+
+    it "doesn't split already-multiline \"\"\"-strings" do
+      set_file_contents <<~EOF
+        string = """
+            something, 'anything'
+        """
+      EOF
+
+      vim.search '"""'
+      split
+
+      assert_file_contents <<~EOF
+        string = """
+            something, 'anything'
+        """
+      EOF
+    end
+
+    it "doesn't split already-multiline '''-strings" do
+      set_file_contents <<~EOF
+        string = '''
+            something, 'anything'
+        '''
+      EOF
+
+      vim.search "'''"
+      split
+
+      assert_file_contents <<~EOF
+        string = '''
+            something, 'anything'
+        '''
+      EOF
+    end
+
     it "splits normal strings into multiline strings" do
       set_file_contents 'string = "\"anything\""'