Resolve goto-def/refs/hover at the end of a symbol (#1038 / #1027)

[lukaszsamson]

Fixes #1038. Addresses the #1027 cases. Supersedes #1087 (the retry-with-char-to-the-left workaround).

Problem

SurroundContext.Toxic.surround_context/2 mirrored Code.Fragment.surround_context/2, which returns :none when the cursor is one column past the last character of a symbol, and returns the enclosing remote call when the cursor is at the end of an alias before a .. So goto-definition / references / hover fail when the caret is at the visual end of a name (#1038), and an alias at its end resolves to the function instead of the module (#1027; the upstream lexical fix elixir-lang/elixir#13150 was reverted as it only handled a few cases).

Fix

The fix is in elixir_sense (PR elixir-lsp/elixir_sense#340); this PR bumps the dependency and adds end-to-end coverage. Because toxic2 gives every node an exact end-exclusive range, the classifier now resolves the trailing edge precisely:

• at the trailing edge of an alias/var/atom/attribute leaf, the leaf wins even over an enclosing dot → end of Foo in Foo.bar() is the module Foo (Inconsistency in go-to definition/references for modules based on syntax #1027);
• otherwise, when the cursor resolves to nothing, retry one column left, surfacing only navigation targets (a key:/operator/sigil trailing edge stays :none) → end of a bare symbol or of a whole remote call resolves (Go to Definition/Find References functionality doesn't work when cursor is at end of symbol #1038).

All four locators (definition/references/implementation/hover) consume surround_context, so they are fixed together.

Safety

Fuzzed across lib + fixtures at every column: 0 results where the cursor falls outside the returned [begin, end], and by construction the result is :none only where the pre-existing classification was — nothing regresses. The 285 existing navigation-locator tests still pass.

Note: the elixir_sense dep is pinned to the #340 branch SHA; it should be advanced to the merge commit once #340 lands.

🤖 Generated with Claude Code

[lukaszsamson]

@codex review

[Copilot]

Pull request overview

This PR updates the pinned elixir_sense dependency to pick up fixes for trailing-edge cursor classification (cursor one column past a symbol / at the end of an alias before .), and adds regression tests in ElixirLS to ensure goto-definition works correctly in those positions.

Changes:

• Bump elixir_sense git ref SHA to a newer commit that includes the trailing-edge surround-context fix.
• Update the repository’s recorded dependency SHA (dep_versions.exs) to match the new pin.
• Add definition-locator regression tests for “cursor at end of symbol” (#1038) and “alias end before . resolves module” (#1027).

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

File	Description
mix.lock	Pins elixir_sense to the updated git SHA.
dep_versions.exs	Updates the tracked elixir_sense SHA to match the lockfile.
apps/language_server/test/providers/definition/locator_test.exs	Adds regression coverage for end-of-symbol and alias-before-dot behavior in goto-definition.

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