This PR fixes a bug where tactic auto-completion would produce tactic
completion items in the entire trailing whitespace of an empty tactic
block. Since #13229 further restricted top-level `by` blocks to be
indentation- sensitive, this PR adjusts the logic to only display
completion items at a "proper" indentation level.
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This PR adds test infrastructure and tests for tactic completion in
empty `by` blocks.
**Test runner improvements (`src/Lean/Server/Test/Runner.lean`):**
- Add `--⬑` marker variant that targets the column of `--` itself,
enabling column 0 tests (which `--^` cannot reach since `^` is always at
column 2+).
**New test file (`tests/server_interactive/completionEmptyBy.lean`):**
- Tests tactic completion in empty `by` blocks for both top-level `by`
and nested `by` (inside `id <| have := by`).
- Tests at various column positions on the line below `by`: indented
past `by`, at column 2, and at column 0.
- Tests on the `by` token itself (no completions expected).
- All positions below `by` currently offer tactic completions.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
