python-lsp
diff --git a/pylsp/hookspecs.py b/pylsp/hookspecs.py
@@ -80,12 +80,12 @@ def pylsp_folding_range(config, workspace, document):
 
 
 @hookspec(firstresult=True)
-def pylsp_format_document(config, workspace, document):
+def pylsp_format_document(config, workspace, document, options):
     pass
 
 
 @hookspec(firstresult=True)
-def pylsp_format_range(config, workspace, document, range):
+def pylsp_format_range(config, workspace, document, range, options):
     pass
 
 

diff --git a/pylsp/plugins/autopep8_format.py b/pylsp/plugins/autopep8_format.py
@@ -13,13 +13,13 @@
 
 
 @hookimpl(tryfirst=True)  # Prefer autopep8 over YAPF
-def pylsp_format_document(config, document):
+def pylsp_format_document(config, document, options=None):  # pylint: disable=unused-argument
     log.info("Formatting document %s with autopep8", document)
     return _format(config, document)
 
 
 @hookimpl(tryfirst=True)  # Prefer autopep8 over YAPF
-def pylsp_format_range(config, document, range):  # pylint: disable=redefined-builtin
+def pylsp_format_range(config, document, range, options=None):  # pylint: disable=redefined-builtin,unused-argument
     log.info("Formatting document %s in range %s with autopep8", document, range)
 
     # First we 'round' the range up/down to full lines only

diff --git a/pylsp/plugins/yapf_format.py b/pylsp/plugins/yapf_format.py
@@ -4,7 +4,7 @@
 import logging
 import os
 
-from yapf.yapflib import file_resources
+from yapf.yapflib import file_resources, style
 from yapf.yapflib.yapf_api import FormatCode
 
 from pylsp import hookimpl
@@ -14,12 +14,12 @@
 
 
 @hookimpl
-def pylsp_format_document(document):
-    return _format(document)
+def pylsp_format_document(document, options=None):
+    return _format(document, options=options)
 
 
 @hookimpl
-def pylsp_format_range(document, range):  # pylint: disable=redefined-builtin
+def pylsp_format_range(document, range, options=None):  # pylint: disable=redefined-builtin
     # First we 'round' the range up/down to full lines only
     range['start']['character'] = 0
     range['end']['line'] += 1
@@ -33,10 +33,10 @@ def pylsp_format_range(document, range):  # pylint: disable=redefined-builtin
 
     # Add 1 for 1-indexing vs LSP's 0-indexing
     lines = [(range['start']['line'] + 1, range['end']['line'] + 1)]
-    return _format(document, lines=lines)
+    return _format(document, lines=lines, options=options)
 
 
-def _format(document, lines=None):
+def _format(document, lines=None, options=None):
     # Yapf doesn't work with CRLF/CR line endings, so we replace them by '\n'
     # and restore them below.
     replace_eols = False
@@ -46,13 +46,50 @@ def _format(document, lines=None):
         replace_eols = True
         source = source.replace(eol_chars, '\n')
 
+    # Get the default styles as a string
+    # for a preset configuration, i.e. "pep8"
+    style_config = file_resources.GetDefaultStyleForDir(
+        os.path.dirname(document.path)
+    )
+    if options is not None:
+        # We have options passed from LSP format request
+        # let's pass them to the formatter.
+        # First we want to get a dictionary of the preset style
+        # to pass instead of a string so that we can modify it
+        style_config = style.CreateStyleFromConfig(style_config)
+
+        use_tabs = style_config['USE_TABS']
+        indent_width = style_config['INDENT_WIDTH']
+
+        if options.get('tabSize') is not None:
+            indent_width = max(int(options.get('tabSize')), 1)
+
+        if options.get('insertSpaces') is not None:
+            # TODO is it guaranteed to be a boolean, or can it be a string?
+            use_tabs = not options.get('insertSpaces')
+
+            if use_tabs:
+                # Indent width doesn't make sense when using tabs
+                # the specifications state: "Size of a tab in spaces"
+                indent_width = 1
+
+        style_config['USE_TABS'] = use_tabs
+        style_config['INDENT_WIDTH'] = indent_width
+        style_config['CONTINUATION_INDENT_WIDTH'] = indent_width
+
+        for style_option, value in options.items():
+            # Apply arbitrary options passed as formatter options
+            if style_option not in style_config:
+                # ignore if it's not a known yapf config
+                continue
+
+            style_config[style_option] = value
+
     new_source, changed = FormatCode(
         source,
         lines=lines,
         filename=document.filename,
-        style_config=file_resources.GetDefaultStyleForDir(
-            os.path.dirname(document.path)
-        )
+        style_config=style_config
     )
 
     if not changed:

diff --git a/pylsp/python_lsp.py b/pylsp/python_lsp.py
@@ -277,11 +277,11 @@ def document_symbols(self, doc_uri):
     def execute_command(self, command, arguments):
         return self._hook('pylsp_execute_command', command=command, arguments=arguments)
 
-    def format_document(self, doc_uri):
-        return self._hook('pylsp_format_document', doc_uri)
+    def format_document(self, doc_uri, options):
+        return self._hook('pylsp_format_document', doc_uri, options=options)
 
-    def format_range(self, doc_uri, range):
-        return self._hook('pylsp_format_range', doc_uri, range=range)
+    def format_range(self, doc_uri, range, options):
+        return self._hook('pylsp_format_range', doc_uri, range=range, options=options)
 
     def highlight(self, doc_uri, position):
         return flatten(self._hook('pylsp_document_highlight', doc_uri, position=position)) or None
@@ -362,19 +362,17 @@ def m_text_document__hover(self, textDocument=None, position=None, **_kwargs):
     def m_text_document__document_symbol(self, textDocument=None, **_kwargs):
         return self.document_symbols(textDocument['uri'])
 
-    def m_text_document__formatting(self, textDocument=None, _options=None, **_kwargs):
-        # For now we're ignoring formatting options.
-        return self.format_document(textDocument['uri'])
+    def m_text_document__formatting(self, textDocument=None, options=None, **_kwargs):
+        return self.format_document(textDocument['uri'], options)
 
     def m_text_document__rename(self, textDocument=None, position=None, newName=None, **_kwargs):
         return self.rename(textDocument['uri'], position, newName)
 
     def m_text_document__folding_range(self, textDocument=None, **_kwargs):
         return self.folding(textDocument['uri'])
 
-    def m_text_document__range_formatting(self, textDocument=None, range=None, _options=None, **_kwargs):
-        # Again, we'll ignore formatting options for now.
-        return self.format_range(textDocument['uri'], range)
+    def m_text_document__range_formatting(self, textDocument=None, range=None, options=None, **_kwargs):
+        return self.format_range(textDocument['uri'], range, options)
 
     def m_text_document__references(self, textDocument=None, position=None, context=None, **_kwargs):
         exclude_declaration = not context['includeDeclaration']

diff --git a/test/plugins/test_yapf_format.py b/test/plugins/test_yapf_format.py
@@ -21,6 +21,9 @@
 """
 
 GOOD_DOC = """A = ['hello', 'world']\n"""
+FOUR_SPACE_DOC = """def hello():
+    pass
+"""
 
 
 def test_format(workspace):
@@ -68,3 +71,27 @@ def test_line_endings(workspace, newline):
     res = pylsp_format_document(doc)
 
     assert res[0]['newText'] == f'import os{newline}import sys{2 * newline}dict(a=1){newline}'
+
+
+def test_format_with_tab_size_option(workspace):
+    doc = Document(DOC_URI, workspace, FOUR_SPACE_DOC)
+    res = pylsp_format_document(doc, {"tabSize": "8"})
+
+    assert len(res) == 1
+    assert res[0]['newText'] == FOUR_SPACE_DOC.replace("    ", "        ")
+
+
+def test_format_with_insert_spaces_option(workspace):
+    doc = Document(DOC_URI, workspace, FOUR_SPACE_DOC)
+    res = pylsp_format_document(doc, {"insertSpaces": False})
+
+    assert len(res) == 1
+    assert res[0]['newText'] == FOUR_SPACE_DOC.replace("    ", "\t")
+
+
+def test_format_with_yapf_specific_option(workspace):
+    doc = Document(DOC_URI, workspace, FOUR_SPACE_DOC)
+    res = pylsp_format_document(doc, {"USE_TABS": True})
+
+    assert len(res) == 1
+    assert res[0]['newText'] == FOUR_SPACE_DOC.replace("    ", "\t")