Problem:
Accepting an item from another completion source raises an error when its
user_data.nvim table does not contain LSP metadata.

Solution:
Retrieve and guard the nested LSP metadata before accessing its fields.

Cover acceptance of a foreign completion item without LSP metadata.

AI-assisted

Problem:
An empty snippet insertText falls back to the label during selection, but
acceptance clears that label and expands an empty string.

Solution:
Require nonempty insertText before expanding a snippet without textEdit.

Extend the omnifunc acceptance fixture with an empty snippet insertion.

AI-assisted

Problem:
A completion list default edit range can replace the explicit range of an
InsertReplaceEdit, filtering out valid items or changing their replacement.

Solution:
Only synthesize a default text edit when the completion item has none.

Extend the existing itemDefaults test for explicit edits with both range variants.

AI-assisted

Problem:
Snippet completion words and previews prefer insertText even when textEdit
is present, although the actual expansion uses textEdit.newText.

Solution:
Use the text edit before the fallback insertion text in both selectors.

Extend the existing precedence test to check the snippet word and preview.

AI-assisted

Problem:
Provider checks start and wait for a job, then execute the same command
again to obtain its output. The returned output can disagree with the
first process's exit status, and the second execution has no timeout.

Solution:
Return the first job's captured output. Bind the output callbacks to
their state and preserve line breaks between callback data entries.
Cover invocation count, multiline stdout, and merged stderr.

AI-assisted

Problem: Repeated default fields and field-by-field assertions obscure
the values that each functional test is meant to check.

Solution: Add eq_partial() to check selected record fields while
preserving list length and order. Use local helpers to fill fixed
expected defaults where tests need full equality. Keep explicit absence
checks and test-specific values at the call sites.

AI-assisted

Problem:
vim.lsp.completion.get() always asks every client that has completion
enabled in the buffer, so a mapping cannot ask just some of them.

Solution:
Add a "client_id" option that limits the request to the given client,
or clients if it is a list.

Problem:
An inherited Git index can leave a plugin checkout empty or prevent
updates.

Solution:
Clear GIT_INDEX_FILE for plugin Git commands. Verify installs and
updates preserve the caller environment and index.

AI-assisted
Signed-off-by: Jake Wang <jakezwang@users.noreply.github.com>

fix(lua): enable param-type-mismatch diagnostic

Problem:
After an LSP client restart, the completion reload callback can use an old
client ID:

    autoread: :checktime failed for buffer 17: Vim:Lua callback:
    ...ed-95df8c0/share/nvim/runtime/lua/vim/lsp/completion.lua:1315: invalid client ID

Solution:
Use the completion augroup for `BufUnload` cleanup.