run mypy in the directory of the nearest pyproject.toml or mypy.ini (#…

…316)

* run mypy in the directory of the nearest pyproject.toml

* check for mypy.ini too

* ${filePyproject} -> ${nearestConfig}

* move `doc is not None` to early guard in get_cwd

* update README.md and add ${nearestConfig} to settings.cwd UI description as well

Co-authored-by: Luciana Abud <45497113+luabud@users.noreply.github.com>

* fixup pyfmt and logs

---------

Co-authored-by: Luciana Abud <45497113+luabud@users.noreply.github.com>

README.md

@@ -47,7 +47,7 @@ There are several settings you can configure to customize the behavior of this e
     <tr>
       <td>mypy-type-checker.cwd</td>
       <td><code>${workspaceFolder}</code></td>
-      <td>Sets the current working directory used to lint Python files with Mypy. By default, it uses the root directory of the workspace <code>${workspaceFolder}</code>. You can set it to <code>${fileDirname}</code> to use the parent folder of the file being linted as the working directory for Mypy.
+      <td>Sets the current working directory used to lint Python files with Mypy. By default, it uses the root directory of the workspace <code>${workspaceFolder}</code>. You can set it to <code>${fileDirname}</code> to use the parent folder of the file being linted as the working directory for Mypy. You can also set it to <code>${nearestConfig}</code> to use the nearest parent/ancestor folder which contains a <code>pyproject.toml</code> or a <code>mypy.ini</code> file.
       </td>
     </tr>
     <tr>

bundled/tool/lsp_server.py

@@ -642,13 +642,39 @@ def _get_env_vars(settings: Dict[str, Any]) -> Dict[str, str]:
 
 def get_cwd(settings: Dict[str, Any], document: Optional[workspace.Document]) -> str:
     """Returns cwd for the given settings and document."""
+    # this happens when running dmypy.
+    if document is None:
+        return settings["workspaceFS"]
+
     if settings["cwd"] == "${workspaceFolder}":
         return settings["workspaceFS"]
 
     if settings["cwd"] == "${fileDirname}":
-        if document is not None:
-            return os.fspath(pathlib.Path(document.path).parent)
-        return settings["workspaceFS"]
+        return os.fspath(pathlib.Path(document.path).parent)
+
+    if settings["cwd"] == "${nearestConfig}":
+        workspaceFolder = pathlib.Path(settings["workspaceFS"])
+        candidate = pathlib.Path(document.path).parent
+        # check if pyproject exists
+        check_for = ["pyproject.toml", "mypy.ini"]
+        # until we leave the workspace
+        while candidate.is_relative_to(workspaceFolder):
+            for n in check_for:
+                candidate_file = candidate / n
+                if candidate_file.is_file():
+                    log_to_output(
+                        f"found {n}, using {candidate}", lsp.MessageType.Debug
+                    )
+                    return os.fspath(candidate)
+            # starting from the current file and working our way up
+            else:
+                candidate = candidate.parent
+        else:
+            log_to_output(
+                f"failed to find {', '.join(check_for)}; using workspace root",
+                lsp.MessageType.Debug,
+            )
+            return settings["workspaceFS"]
 
     return settings["cwd"]
 

package.nls.json

@@ -2,7 +2,7 @@
     "extension.description": "Type checking support for Python files using Mypy.",
     "command.restartServer": "Restart Server",
     "settings.args.description": "Arguments passed to Mypy to enable type checking on Python files. Each argument should be provided as a separate string in the array. \n Example: \n `\"mypy-type-checker.args\" = [\"--config-file=<file>\"]`",
-    "settings.cwd.description": "Sets the current working directory used to lint Python files with Mypy. By default, it uses the root directory of the workspace `${workspaceFolder}`. You can set it to `${fileDirname}` to use the parent folder of the file being linted as the working directory for Mypy.",
+    "settings.cwd.description": "Sets the current working directory used to lint Python files with Mypy. By default, it uses the root directory of the workspace `${workspaceFolder}`. You can set it to `${fileDirname}` to use the parent folder of the file being linted as the working directory for Mypy. You can also set it to `${nearestConfig}` to use the nearest parent/ancestor folder which contains a `pyproject.toml` or a `mypy.ini` file.",
     "settings.severity.description": "Mapping of Mypy's message types to VS Code's diagnostic severity levels as displayed in the Problems window. You can also use it to override specific Mypy error codes. <br>For example: `{\"error\": \"Error\", \"note\": \"Information\", \"name-defined\": \"Warning\" }`",
     "settings.path.description": "Path or command to be used by the extension to type check Python files with Mypy. Accepts an array of a single or multiple strings. If passing a command, each argument should be provided as a separate string in the array. If set to `[\"mypy\"]`, it will use the version of Mypy available in the `PATH` environment variable. <br> Note: Using this option may slowdown type checking. \n Examples: \n- `[\"~/global_env/mypy\"]` \n- `[\"conda\", \"run\", \"-n\", \"lint_env\", \"python\", \"-m\", \"mypy\"]`",
     "settings.ignorePatterns.description": "Configure [glob patterns](https://docs.python.org/3/library/fnmatch.html) as supported by the fnmatch Python library to exclude files or folders from being linted with Mypy.",

src/common/server.ts

@@ -27,7 +27,18 @@ async function createServer(
     initializationOptions: IInitOptions,
 ): Promise<LanguageClient> {
     const command = settings.interpreter[0];
-    const cwd = settings.cwd === '${fileDirname}' ? Uri.parse(settings.workspace).fsPath : settings.cwd;
+    let cwd: string;
+    if (settings.cwd === '${fileDirname}') {
+        cwd = Uri.parse(settings.workspace).fsPath;
+    } else if (settings.cwd === '${nearestConfig}') {
+        cwd = Uri.parse(settings.workspace).fsPath;
+    } else {
+        cwd = settings.cwd;
+    }
+
+    if (!fsapi.existsSync(cwd)) {
+        traceError(`Server cwd ${cwd} doesn't exist, server startup will probably fail`);
+    }
 
     // Set debugger path needed for debugging python code.
     const newEnv = { ...process.env };