Add basic Goto Implementation Request support

Author: smheidrich

CONFIGURATION.md

@@ -72,6 +72,7 @@ This server can be configured using the `workspace/didChangeConfiguration` metho
 | `pylsp.plugins.rope_autoimport.memory` | `boolean` | Make the autoimport database memory only. Drastically increases startup time. | `false` |
 | `pylsp.plugins.rope_completion.enabled` | `boolean` | Enable or disable the plugin. | `false` |
 | `pylsp.plugins.rope_completion.eager` | `boolean` | Resolve documentation and detail eagerly. | `false` |
+| `pylsp.plugins.rope_implementation.enabled` | `boolean` | Enable or disable the plugin. | `true` |
 | `pylsp.plugins.yapf.enabled` | `boolean` | Enable or disable the plugin. | `true` |
 | `pylsp.rope.extensionModules` | `string` | Builtin and c-extension modules that are allowed to be imported and inspected by rope. | `null` |
 | `pylsp.rope.ropeFolder` | `array` of unique `string` items | The name of the folder in which rope stores project configurations and data.  Pass `null` for not using such a folder at all. | `null` |

README.md

@@ -15,7 +15,7 @@ pip install python-lsp-server
 This will expose the command `pylsp` on your PATH. Confirm that installation succeeded by running `pylsp --help`.
 
 If the respective dependencies are found, the following optional providers will be enabled:
-- [Rope](https://github.com/python-rope/rope) for Completions and renaming
+- [Rope](https://github.com/python-rope/rope) for Completions, Goto Implementation, and renaming
 - [Pyflakes](https://github.com/PyCQA/pyflakes) linter to detect various errors
 - [McCabe](https://github.com/PyCQA/mccabe) linter for complexity checking
 - [pycodestyle](https://github.com/PyCQA/pycodestyle) linter for style checking
@@ -151,7 +151,7 @@ pip install 'python-lsp-server[websockets]'
 * Code Linting
 * Code actions
 * Signature Help
-* Go to definition
+* Go to definition or implementation
 * Hover
 * Find References
 * Document Symbols

pylsp/hookspecs.py

@@ -93,6 +93,11 @@ def pylsp_hover(config, workspace, document, position) -> None:
     pass
 
 
+@hookspec
+def pylsp_implementations(config, workspace, document, position) -> None:
+    pass
+
+
 @hookspec
 def pylsp_initialize(config, workspace) -> None:
     pass

pylsp/plugins/rope_implementation.py

@@ -0,0 +1,42 @@
+# Copyright 2017-2020 Palantir Technologies, Inc.
+# Copyright 2021- Python Language Server Contributors.
+import logging
+import os
+
+from rope.contrib.findit import find_implementations
+
+from pylsp import hookimpl, uris
+
+log = logging.getLogger(__name__)
+
+
+@hookimpl
+def pylsp_settings():
+    # Default to enabled (no reason not to)
+    return {"plugins": {"rope_implementation": {"enabled": True}}}
+
+
+@hookimpl
+def pylsp_implementations(config, workspace, document, position):
+    offset = document.offset_at_position(position)
+    rope_config = config.settings(document_path=document.path).get("rope", {})
+    rope_project = workspace._rope_project_builder(rope_config)
+    rope_resource = document._rope_resource(rope_config)
+
+    impls = find_implementations(rope_project, rope_resource, offset)
+
+    return [
+        {
+            "uri": uris.uri_with(
+                document.uri, path=str(os.path.abspath(impl.resource.path))
+            ),
+            "range": {
+                # TODO: `impl.region` seems to be from the start of the file
+                # and offsets from the start of the line difficult to obtain,
+                # so we just return the whole line for now:
+                "start": {"line": impl.lineno - 1, "character": 0},
+                "end": {"line": impl.lineno - 1, "character": 999},
+            },
+        }
+        for impl in impls
+    ]

pylsp/python_lsp.py

@@ -280,6 +280,7 @@ def capabilities(self):
                 "commands": flatten(self._hook("pylsp_commands"))
             },
             "hoverProvider": True,
+            "implementationProvider": True,  # only when Rope is installed
             "referencesProvider": True,
             "renameProvider": True,
             "foldingRangeProvider": True,
@@ -436,6 +437,9 @@ def highlight(self, doc_uri, position):
     def hover(self, doc_uri, position):
         return self._hook("pylsp_hover", doc_uri, position=position) or {"contents": ""}
 
+    def implementations(self, doc_uri, position):
+        return flatten(self._hook("pylsp_implementations", doc_uri, position=position))
+
     @_utils.debounce(LINT_DEBOUNCE_S, keyed_by="doc_uri")
     def lint(self, doc_uri, is_saved) -> None:
         # Since we're debounced, the document may no longer be open
@@ -762,6 +766,12 @@ def m_text_document__definition(self, textDocument=None, position=None, **_kwarg
             return self._cell_document__definition(document, position, **_kwargs)
         return self.definitions(textDocument["uri"], position)
 
+    def m_text_document__implementation(self, textDocument=None, position=None, **_kwargs):
+        # textDocument here is just a dict with a uri
+        workspace = self._match_uri_to_workspace(textDocument["uri"])
+        document = workspace.get_document(textDocument["uri"])
+        return self.implementations(textDocument["uri"], position)
+
     def m_text_document__document_highlight(
         self, textDocument=None, position=None, **_kwargs
     ):

pyproject.toml

@@ -80,6 +80,7 @@ pyflakes = "pylsp.plugins.pyflakes_lint"
 pylint = "pylsp.plugins.pylint_lint"
 rope_completion = "pylsp.plugins.rope_completion"
 rope_autoimport = "pylsp.plugins.rope_autoimport"
+rope_implementation = "pylsp.plugins.rope_implementation"
 yapf = "pylsp.plugins.yapf_format"
 
 [project.scripts]