Create extra regions for diagnostics with tags

docs/src/features.md

@@ -223,6 +223,35 @@ The following tables give an overview about the scope names used by LSP.
 !!! note
     If `diagnostics_highlight_style` is set to "fill" in the LSP settings, the highlighting color can be controlled via the "background" color from a color scheme rule for the listed scopes.
 
+Diagnostics will also optionally include the following scopes:
+
+| scope                    | diagnostic tag name | description                 |
+| ------------------------ | ------------------- | --------------------------- |
+| `markup.unnecessary.lsp` | Unnecessary         | Unused or unnecessary code  |
+| `markup.deprecated.lsp`  | Deprecated          | Deprecated or obsolete code |
+
+!!! note
+    Regions created for those scopes don't follow the `diagnostics_highlight_style` setting and instead always use the "fill" style.
+
+    Those scopes can be used to, for example, gray-out the text color of unused code, if the server supports that.
+
+    For example, to add a custom rule for `Mariana` color scheme, select `UI: Customize Color Scheme` from the Command Palette and add the following rule:
+
+    ```json
+    {
+        "rules": [
+            {
+                "scope": "markup.unnecessary.lsp",
+                "foreground": "color(rgb(255, 255, 255) alpha(0.4))",
+                "background": "color(var(blue3) alpha(0.9))"
+            }
+        ]
+    }
+    ```
+
+    The color scheme rule only works if the "background" color is different from the global background of the scheme. So for other color schemes, ideally pick a background color that is as close as possible, but marginally different from the original background.
+
+
 #### Signature Help
 
 | scope | description |

plugin/core/protocol.py

@@ -16,6 +16,11 @@ class DiagnosticSeverity:
     Hint = 4
 
 
+class DiagnosticTag:
+    Unnecessary = 1
+    Deprecated = 2
+
+
 class CompletionItemTag:
     Deprecated = 1
 
@@ -174,6 +179,13 @@ class SignatureHelpTriggerKind:
 }, total=True)
 
 
+PublishDiagnosticsParams = TypedDict('PublishDiagnosticsParams', {
+    'uri': DocumentUri,
+    'version': Optional[int],
+    'diagnostics': List[Diagnostic],
+}, total=False)
+
+
 class Request:
 
     __slots__ = ('method', 'params', 'view', 'progress')

plugin/core/sessions.py

@@ -11,6 +11,7 @@
 from .protocol import CodeAction
 from .protocol import Command
 from .protocol import CompletionItemTag
+from .protocol import DiagnosticTag
 from .protocol import Diagnostic
 from .protocol import Error
 from .protocol import ErrorCode
@@ -115,6 +116,7 @@ def get_initialize_params(variables: Dict[str, str], workspace_folders: List[Wor
                           config: ClientConfig) -> dict:
     completion_kinds = list(range(1, len(COMPLETION_KINDS) + 1))
     symbol_kinds = list(range(1, len(SYMBOL_KINDS) + 1))
+    diagnostic_tag_value_set = [v for k, v in DiagnosticTag.__dict__.items() if not k.startswith('_')]
     completion_tag_value_set = [v for k, v in CompletionItemTag.__dict__.items() if not k.startswith('_')]
     symbol_tag_value_set = [v for k, v in SymbolTag.__dict__.items() if not k.startswith('_')]
     first_folder = workspace_folders[0] if workspace_folders else None
@@ -236,6 +238,9 @@ def get_initialize_params(variables: Dict[str, str], workspace_folders: List[Wor
             },
             "publishDiagnostics": {
                 "relatedInformation": True,
+                "tagSupport": {
+                    "valueSet": diagnostic_tag_value_set
+                },
                 "versionSupport": True,
                 "codeDescriptionSupport": True,
                 "dataSupport": True

plugin/session_buffer.py

@@ -1,7 +1,8 @@
-from .core.protocol import Diagnostic, Range
+from .core.protocol import Diagnostic
 from .core.protocol import DiagnosticSeverity
 from .core.protocol import TextDocumentSyncKindFull
 from .core.protocol import TextDocumentSyncKindNone
+from .core.protocol import Range
 from .core.sessions import SessionViewProtocol
 from .core.settings import userprefs
 from .core.types import Capabilities
@@ -38,13 +39,14 @@ def update(self, version: int, changes: Iterable[sublime.TextChange]) -> None:
 
 class DiagnosticSeverityData:
 
-    __slots__ = ('regions', 'annotations', 'panel_contribution', 'scope', 'icon')
+    __slots__ = ('regions', 'regions_with_tag', 'annotations', 'panel_contribution', 'scope', 'icon')
 
     def __init__(self, severity: int) -> None:
         self.regions = []  # type: List[sublime.Region]
+        self.regions_with_tag = {}  # type: Dict[int, List[sublime.Region]]
         self.annotations = []  # type: List[str]
         self.panel_contribution = []  # type: List[Tuple[str, Optional[int], Optional[str], Optional[str]]]
-        _, __, self.scope, self.icon = DIAGNOSTIC_SEVERITY[severity - 1]
+        _, _, self.scope, self.icon = DIAGNOSTIC_SEVERITY[severity - 1]
         if userprefs().diagnostics_gutter_marker != "sign":
             self.icon = userprefs().diagnostics_gutter_marker
 
@@ -263,7 +265,12 @@ def on_diagnostics_async(self, raw_diagnostics: List[Diagnostic], version: Optio
                     data = DiagnosticSeverityData(severity)
                     data_per_severity[severity] = data
                 region = range_to_region(Range.from_lsp(diagnostic["range"]), view)
-                data.regions.append(region)
+                tags = diagnostic.get('tags', [])
+                if tags:
+                    for tag in tags:
+                        data.regions_with_tag.setdefault(tag, []).append(region)
+                else:
+                    data.regions.append(region)
                 diagnostics.append((diagnostic, region))
                 if severity == DiagnosticSeverity.Error:
                     total_errors += 1

plugin/session_view.py

@@ -1,4 +1,5 @@
 from .core.progress import ViewProgressReporter
+from .core.protocol import DiagnosticTag
 from .core.protocol import Notification
 from .core.protocol import Request
 from .core.sessions import Session
@@ -13,6 +14,8 @@
 import sublime
 import functools
 
+DIAGNOSTIC_TAG_VALUES = [v for (k, v) in DiagnosticTag.__dict__.items() if not k.startswith('_')]
+
 
 class SessionView:
     """
@@ -173,20 +176,37 @@ def shutdown_async(self) -> None:
     def diagnostics_key(self, severity: int) -> str:
         return "lsp{}d{}".format(self.session.config.name, severity)
 
+    def diagnostics_tag_scope(self, tag: int) -> Optional[str]:
+        for k, v in DiagnosticTag.__dict__.items():
+            if v == tag:
+                return 'markup.{}.lsp'.format(k.lower())
+        return None
+
     def present_diagnostics_async(self, flags: int) -> None:
         data_per_severity = self.session_buffer.data_per_severity
         for severity in reversed(range(1, len(DIAGNOSTIC_SEVERITY) + 1)):
             key = self.diagnostics_key(severity)
+            key_tags = {tag: '{}_tags_{}'.format(key, tag) for tag in DIAGNOSTIC_TAG_VALUES}
             data = data_per_severity.get(severity)
             if data is None:
                 self.view.erase_regions(key)
+                for key_tag in key_tags.values():
+                    self.view.erase_regions(key_tag)
             elif ((severity <= userprefs().show_diagnostics_severity_level) and
                     (data.icon or flags != (sublime.DRAW_NO_FILL | sublime.DRAW_NO_OUTLINE))):
-                # allow showing diagnostics with same begin and end range in the view
-                flags |= sublime.DRAW_EMPTY
-                self.view.add_regions(key, data.regions, data.scope, data.icon, flags)
+                non_tag_regions = data.regions
+                for tag, regions in data.regions_with_tag.items():
+                    tag_scope = self.diagnostics_tag_scope(tag)
+                    # Trick to only add tag regions if there is a corresponding color scheme scope defined.
+                    if tag_scope and 'background' in self.view.style_for_scope(tag_scope):
+                        self.view.add_regions(key_tags[tag], regions, tag_scope, flags=sublime.DRAW_NO_OUTLINE)
+                    else:
+                        non_tag_regions.extend(regions)
+                self.view.add_regions(key, non_tag_regions, data.scope, data.icon, flags | sublime.DRAW_EMPTY)
             else:
                 self.view.erase_regions(key)
+                for key_tag in key_tags.values():
+                    self.view.erase_regions(key_tag)
         listener = self.listener()
         if listener:
             listener.on_diagnostics_updated_async()

tests/test_server_notifications.py

@@ -1,6 +1,8 @@
+from LSP.plugin.core.protocol import DiagnosticSeverity
+from LSP.plugin.core.protocol import DiagnosticTag
+from LSP.plugin.core.protocol import PublishDiagnosticsParams
 from LSP.plugin.core.typing import Generator
 from LSP.plugin.core.url import filename_to_uri
-from LSP.plugin.core.protocol import DiagnosticSeverity
 from setup import TextDocumentTestCase
 import sublime
 
@@ -9,8 +11,8 @@ class ServerNotifications(TextDocumentTestCase):
 
     def test_publish_diagnostics(self) -> Generator:
         self.insert_characters("a b c\n")
-        yield from self.await_client_notification("textDocument/publishDiagnostics", {
-            'uri': filename_to_uri(self.view.file_name()),
+        params = {
+            'uri': filename_to_uri(self.view.file_name() or ''),
             'diagnostics': [
                 {
                     'message': "foo",
@@ -28,18 +30,24 @@ def test_publish_diagnostics(self) -> Generator:
                     'message': "baz",
                     'severity': DiagnosticSeverity.Information,
                     'source': 'qux',
-                    'range': {'end': {'character': 5, 'line': 0}, 'start': {'character': 4, 'line': 0}}
+                    'range': {'end': {'character': 5, 'line': 0}, 'start': {'character': 4, 'line': 0}},
+                    'tags': [DiagnosticTag.Unnecessary]
                 }
             ]
-        })
+        }  # type: PublishDiagnosticsParams
+        yield from self.await_client_notification("textDocument/publishDiagnostics", params)
         yield lambda: len(self.view.get_regions("lspTESTd1")) > 0
         yield lambda: len(self.view.get_regions("lspTESTd2")) > 0
         yield lambda: len(self.view.get_regions("lspTESTd3")) > 0
+        yield lambda: len(self.view.get_regions("lspTESTd3_tags")) == 0
         errors = self.view.get_regions("lspTESTd1")
         warnings = self.view.get_regions("lspTESTd2")
         info = self.view.get_regions("lspTESTd3")
+        self.assertEqual(len(errors), 1)
         self.assertEqual(errors[0], sublime.Region(0, 1))
+        self.assertEqual(len(warnings), 1)
         self.assertEqual(warnings[0], sublime.Region(2, 3))
+        self.assertEqual(len(info), 1)
         self.assertEqual(info[0], sublime.Region(4, 5))
 
         # Testing whether the popup with the diagnostic moves along with next_result