impl Completions: Auto add function call parenthesis #2207

[asukaminato0721]

Summary

Fixes part of #2207

Added optional auto‑parentheses for function/method completion items behind python.analysis.completeFunctionParens, with snippet insertion when the client supports it.

Plumbed the setting through LSP config, exposed it in the VS Code settings.

Test Plan

Added an LSP interaction test that asserts snippet behavior.

[Copilot]

Pull request overview

Adds an opt-in completion behavior to automatically insert () for function/method completion items (using snippets when supported), exposed via python.analysis.completeFunctionParens and validated with an LSP interaction test.

Changes:

• Add python.analysis.completeFunctionParens VS Code setting and plumb it through the server’s analysis config.
• Detect client snippet support and emit snippet-based insertText (name($0)) when available, otherwise plain text (name()).
• Add an LSP interaction test asserting snippet completion behavior.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
pyrefly/lib/test/lsp/lsp_interaction/completion.rs	Adds an interaction test to validate snippet insertion when auto-parens is enabled.
pyrefly/lib/state/lsp.rs	Implements auto-parens mutation of completion items for functions/methods behind new flags.
pyrefly/lib/lsp/non_wasm/workspace.rs	Adds complete_function_parens to the deserialized analysis config.
pyrefly/lib/lsp/non_wasm/server.rs	Wires config + client snippet capability into completion request handling.
lsp/package.json	Exposes python.analysis.completeFunctionParens in VS Code settings UI.
Cargo.lock	Updates lockfile checksum entry.

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[Copilot]

The new behavior has two branches (snippet vs. non-snippet clients), but this test only asserts the snippet path. Consider adding a companion test (or an additional assertion) with snippetSupport: false to verify the plain-text insertion uses spam() and does not set insertTextFormat to SNIPPET.

[Copilot]

completion_with_incomplete_with_function_parens adds multiple boolean parameters, which makes call sites harder to read and easy to misuse. Consider introducing a small options struct (e.g., CompletionOptions { complete_function_parens, supports_snippets, ... }) or an enum/bitflags to keep the API self-documenting as more completion features are added.

[jvansch1]

I think this is good advice. We should probably add something simple here

[meta-codesync]

@jvansch1 has imported this pull request. If you are a Meta employee, you can view this in D92050705.

[github-actions]

According to mypy_primer, this change doesn't affect type check results on a corpus of open source code. ✅

[kinto0]

Review automatically exported from Phabricator review in Meta.

[meta-codesync]

@jvansch1 merged this pull request in cf5807b.