feat: lint rule no missing external will create file

sqlmesh/core/linter/rule.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import abc
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from pathlib import Path
 
 from sqlmesh.core.model import Model
@@ -49,12 +49,21 @@ class TextEdit:
     new_text: str
 
 
+@dataclass(frozen=True)
+class CreateFile:
+    """Create a new file with the provided text."""
+
+    path: Path
+    text: str
+
+
 @dataclass(frozen=True)
 class Fix:
     """A fix that can be applied to resolve a rule violation."""
 
     title: str
-    edits: t.List[TextEdit]
+    edits: t.List[TextEdit] = field(default_factory=list)
+    create_files: t.List[CreateFile] = field(default_factory=list)
 
 
 class _Rule(abc.ABCMeta):

sqlmesh/core/linter/rules/builtin.py

@@ -14,7 +14,15 @@
     get_range_of_model_block,
     read_range_from_string,
 )
-from sqlmesh.core.linter.rule import Rule, RuleViolation, Range, Fix, TextEdit, Position
+from sqlmesh.core.linter.rule import (
+    Rule,
+    RuleViolation,
+    Range,
+    Fix,
+    TextEdit,
+    Position,
+    CreateFile,
+)
 from sqlmesh.core.linter.definition import RuleSet
 from sqlmesh.core.model import Model, SqlModel, ExternalModel
 from sqlmesh.utils.lineage import extract_references_from_query, ExternalModelReference
@@ -227,7 +235,16 @@ def create_fix(self, model_name: str) -> t.Optional[Fix]:
 
         external_models_path = root / EXTERNAL_MODELS_YAML
         if not external_models_path.exists():
-            return None
+            return Fix(
+                title="Add external model file",
+                edits=[],
+                create_files=[
+                    CreateFile(
+                        path=external_models_path,
+                        text=f"- name: '{model_name}'\n",
+                    )
+                ],
+            )
 
         # Figure out the position to insert the new external model at the end of the file, whether
         # needs new line or not.

sqlmesh/lsp/context.py

@@ -273,13 +273,41 @@ def get_code_actions(
             if found_violation is not None and found_violation.fixes:
                 # Create code actions for each fix
                 for fix in found_violation.fixes:
-                    # Convert our Fix to LSP TextEdits
                     changes: t.Dict[str, t.List[types.TextEdit]] = {}
+                    document_changes: t.List[
+                        t.Union[
+                            types.TextDocumentEdit,
+                            types.CreateFile,
+                            types.RenameFile,
+                            types.DeleteFile,
+                        ]
+                    ] = []
+
+                    for create in fix.create_files:
+                        create_uri = URI.from_path(create.path).value
+                        document_changes.append(types.CreateFile(uri=create_uri))
+                        document_changes.append(
+                            types.TextDocumentEdit(
+                                text_document=types.OptionalVersionedTextDocumentIdentifier(
+                                    uri=create_uri,
+                                    version=None,
+                                ),
+                                edits=[
+                                    types.TextEdit(
+                                        range=types.Range(
+                                            start=types.Position(line=0, character=0),
+                                            end=types.Position(line=0, character=0),
+                                        ),
+                                        new_text=create.text,
+                                    )
+                                ],
+                            )
+                        )
+
                     for edit in fix.edits:
                         uri_key = URI.from_path(edit.path).value
                         if uri_key not in changes:
                             changes[uri_key] = []
-                        # Create a TextEdit for the LSP
                         changes[uri_key].append(
                             types.TextEdit(
                                 range=types.Range(
@@ -296,12 +324,15 @@ def get_code_actions(
                             )
                         )
 
-                    # Create the code action
+                    workspace_edit = types.WorkspaceEdit(
+                        changes=changes if changes else None,
+                        document_changes=document_changes if document_changes else None,
+                    )
                     code_action = types.CodeAction(
                         title=fix.title,
                         kind=types.CodeActionKind.QuickFix,
                         diagnostics=[diagnostic],
-                        edit=types.WorkspaceEdit(changes=changes),
+                        edit=workspace_edit,
                     )
                     code_actions.append(code_action)
 

tests/core/linter/test_builtin.py

@@ -51,7 +51,13 @@ def test_no_missing_external_models(tmp_path, copy_to_temp_path) -> None:
         lint.violation_msg
         == """Model '"memory"."sushi"."customers"' depends on unregistered external model '"memory"."raw"."demographics"'. Please register it in the external models file. This can be done by running 'sqlmesh create_external_models'."""
     )
-    assert len(lint.fixes) == 0
+    assert len(lint.fixes) == 1
+    fix = lint.fixes[0]
+    assert len(fix.edits) == 0
+    assert len(fix.create_files) == 1
+    create = fix.create_files[0]
+    assert create.path == sushi_path / "external_models.yaml"
+    assert create.text == '- name: \'"memory"."raw"."demographics"\'\n'
 
 
 def test_no_missing_external_models_with_existing_file_ending_in_newline(

tests/lsp/test_code_actions.py

@@ -1,4 +1,5 @@
 import typing as t
+import os
 from lsprotocol import types
 from sqlmesh.core.context import Context
 from sqlmesh.lsp.context import LSPContext
@@ -109,3 +110,73 @@ def test_code_actions_with_linting(copy_to_temp_path: t.Callable):
         URI.from_path(sushi_path / "models" / "latest_order.sql").value
     ]
     assert len(text_edits) > 0
+
+
+def test_code_actions_create_file(copy_to_temp_path: t.Callable) -> None:
+    sushi_paths = copy_to_temp_path("examples/sushi")
+    sushi_path = sushi_paths[0]
+
+    # Remove external models file and enable linter
+    os.remove(sushi_path / "external_models.yaml")
+    config_path = sushi_path / "config.py"
+    with config_path.open("r") as f:
+        content = f.read()
+
+    before = """    linter=LinterConfig(
+        enabled=False,
+        rules=[
+            "ambiguousorinvalidcolumn",
+            "invalidselectstarexpansion",
+            "noselectstar",
+            "nomissingaudits",
+            "nomissingowner",
+            "nomissingexternalmodels",
+        ],
+    ),"""
+    after = """linter=LinterConfig(enabled=True, rules=["nomissingexternalmodels"]),"""
+    content = content.replace(before, after)
+    with config_path.open("w") as f:
+        f.write(content)
+
+    context = Context(paths=[str(sushi_path)])
+    lsp_context = LSPContext(context)
+
+    uri = URI.from_path(sushi_path / "models" / "customers.sql")
+    violations = lsp_context.lint_model(uri)
+
+    diagnostics = []
+    for violation in violations:
+        if violation.violation_range:
+            diagnostics.append(
+                types.Diagnostic(
+                    range=types.Range(
+                        start=types.Position(
+                            line=violation.violation_range.start.line,
+                            character=violation.violation_range.start.character,
+                        ),
+                        end=types.Position(
+                            line=violation.violation_range.end.line,
+                            character=violation.violation_range.end.character,
+                        ),
+                    ),
+                    message=violation.violation_msg,
+                    severity=types.DiagnosticSeverity.Warning,
+                )
+            )
+
+    params = types.CodeActionParams(
+        text_document=types.TextDocumentIdentifier(uri=uri.value),
+        range=types.Range(
+            start=types.Position(line=0, character=0), end=types.Position(line=1, character=0)
+        ),
+        context=types.CodeActionContext(diagnostics=diagnostics),
+    )
+
+    actions = lsp_context.get_code_actions(uri, params)
+    assert actions is not None and len(actions) > 0
+    action = next(a for a in actions if isinstance(a, types.CodeAction))
+    assert action.edit is not None
+    assert action.edit.document_changes is not None
+    create_file = [c for c in action.edit.document_changes if isinstance(c, types.CreateFile)]
+    assert create_file, "Expected a CreateFile operation"
+    assert create_file[0].uri == URI.from_path(sushi_path / "external_models.yaml").value