Add NormalizeComments transformer for fixing space after #

docs/releasenotes/4.0.0.rst

@@ -180,6 +180,33 @@ it will generate::
 
 Read the transformer documentation for more details on configuring your own custom template.
 
+New transformer NormalizeComments (#290)
+-----------------------------------------
+
+``NormalizeComments`` handles comments formatting. For now, it only focuses on fixing ``missing-space-after-comment``
+rule violations from the Robocop::
+
+    *** Settings ***
+    #linecomment
+    ### header
+
+
+    *** Keywords ***
+    Keyword
+        Step  #comment
+
+will be transformed to::
+
+    *** Settings ***
+    # linecomment
+    ### header
+
+
+    *** Keywords ***
+    Keyword
+        Step  # comment
+    ```
+
 Group comments with settings in OrderSettings (#468)
 ----------------------------------------------------
 

docs/source/transformers/NormalizeComments.rst

@@ -0,0 +1,47 @@
+.. _NormalizeComments:
+
+NormalizeComments
+================================
+
+Normalize comments.
+
+.. |TRANSFORMERNAME| replace:: NormalizeComments
+.. include:: enabled_hint.txt
+
+Normalizes spacing after the beginning of the comment. Fixes ``missing-space-after-comment`` rule violations
+from the Robocop.
+
+.. tab-set::
+
+    .. tab-item:: Before
+
+        .. code:: robotframework
+
+            *** Settings ***
+            #linecomment
+            ### header
+
+
+            *** Keywords ***
+            Keyword
+                Step  #comment
+
+    .. tab-item:: After
+
+        .. code:: robotframework
+
+            *** Settings ***
+            # linecomment
+            ### header
+
+
+            *** Keywords ***
+            Keyword
+                Step  # comment
+
+Skip formatting
+----------------
+
+It is possible to use the following arguments to skip formatting of the code:
+
+- :ref:`skip comments`

robotidy/transformers/NormalizeComments.py

@@ -0,0 +1,73 @@
+from robot.api.parsing import Token
+
+from robotidy.skip import Skip
+from robotidy.transformers import Transformer
+
+
+class NormalizeComments(Transformer):
+    """
+    Normalize comments.
+
+    Normalizes spacing after beginning of the comment. Fixes ``missing-space-after-comment`` rule violations
+    from the Robocop.
+
+    Following code:
+
+    ```robotframework
+    *** Settings ***
+    #linecomment
+    ### header
+
+
+    *** Keywords ***
+    Keyword
+        Step  #comment
+    ```
+
+    will be transformed to:
+
+    ```robotframework
+    *** Settings ***
+    # linecomment
+    ### header
+
+
+    *** Keywords ***
+    Keyword
+        Step  # comment
+    ```
+    """
+
+    HANDLES_SKIP = frozenset(
+        {
+            "skip_comments",
+            "skip_block_comments",
+        }
+    )
+
+    def __init__(self, skip: Skip = None):
+        super().__init__(skip=skip)
+
+    def visit_Comment(self, node):  # noqa
+        return self.handle_comments(node)
+
+    def visit_Statement(self, node):  # noqa
+        return self.handle_comments(node)
+
+    def handle_comments(self, node):
+        if self.skip.comment(node):
+            return node
+        for line in node.lines:
+            for token in line:
+                if token.type == Token.COMMENT:
+                    self.fix_comment_spacing(token)
+                    break  # ignore other comments in the same line
+        return node
+
+    @staticmethod
+    def fix_comment_spacing(comment):
+        # for example content of whole *** Comments *** does not require #
+        if len(comment.value) == 1 or not comment.value.startswith("#"):
+            return
+        if comment.value[1] not in (" ", "#"):
+            comment.value = f"# {comment.value[1:]}"

robotidy/transformers/__init__.py

@@ -59,6 +59,7 @@
     "ReplaceBreakContinue",
     "InlineIf",
     "Translate",
+    "NormalizeComments",
 ]
 
 

tests/atest/transformers/NormalizeComments/expected/test.robot

@@ -0,0 +1,72 @@
+##comment
+# comment
+# comment
+#  comment
+#    comment
+# robotidy: off
+# robotidy:  on
+
+
+*** Settings ***
+# comment
+# comment
+#  comment
+#    comment
+# robotidy: off
+# robotidy:  on
+Suite Setup    Keyword  # comment
+Suite Teardown  Keyword  # comment
+Default Tags    tag
+...  tag2  # comment
+
+
+*** Variables ***
+# comment
+# comment
+#  comment
+#    comment
+# robotidy: off
+# robotidy:  on
+
+${VARIABLE}  # comment
+@{LIST
+...  element  # comment
+
+*** Test Cases ***
+# comment
+# comment
+#  comment
+#    comment
+# robotidy: off
+# robotidy:  on
+
+Test Case
+    # comment
+    Step
+    ...  arg  # comment
+    ${assign}  # comment
+    ...    ${assign2}  # Comment
+    Keyword
+
+*** Keywords ***
+# comment
+# comment
+#  comment
+#    comment
+# robotidy: off
+# robotidy:  on
+
+Keyword
+    # comment
+    Step
+    ...  arg  # comment
+    FOR    ${var}    IN   ${LIST}  # comment
+        # comment
+        Step
+        ...  arg  # comment
+    END
+    TRY  # comment
+        # comment
+    FINALLY
+        # comment
+    END

tests/atest/transformers/NormalizeComments/source/test.robot

@@ -0,0 +1,72 @@
+##comment
+#comment
+# comment
+#  comment
+#    comment
+# robotidy: off
+#robotidy:  on
+
+
+*** Settings ***
+#comment
+# comment
+#  comment
+#    comment
+# robotidy: off
+#robotidy:  on
+Suite Setup    Keyword  # comment
+Suite Teardown  Keyword  #comment
+Default Tags    tag
+...  tag2  #comment
+
+
+*** Variables ***
+#comment
+# comment
+#  comment
+#    comment
+# robotidy: off
+#robotidy:  on
+
+${VARIABLE}  #comment
+@{LIST
+...  element  #comment
+
+*** Test Cases ***
+#comment
+# comment
+#  comment
+#    comment
+# robotidy: off
+#robotidy:  on
+
+Test Case
+    #comment
+    Step
+    ...  arg  #comment
+    ${assign}  #comment
+    ...    ${assign2}  #Comment
+    Keyword
+
+*** Keywords ***
+#comment
+# comment
+#  comment
+#    comment
+# robotidy: off
+#robotidy:  on
+
+Keyword
+    #comment
+    Step
+    ...  arg  #comment
+    FOR    ${var}    IN   ${LIST}  #comment
+        #comment
+        Step
+        ...  arg  #comment
+    END
+    TRY  #comment
+        #comment
+    FINALLY
+        #comment
+    END

tests/atest/transformers/NormalizeComments/test_transformer.py

@@ -0,0 +1,8 @@
+from .. import TransformerAcceptanceTest
+
+
+class TestNormalizeComments(TransformerAcceptanceTest):
+    TRANSFORMER_NAME = "NormalizeComments"
+
+    def test_transformer(self):
+        self.compare(source="test.robot", expected="test.robot")