feat: tree-sitter query files for variable detection (bash, JS, Lua, C, Zig) by Copilot · Pull Request #204 · andrewferrier/debugprint.nvim

Copilot · 2026-03-04T12:10:36Z

Original prompt

The objective is to create a proof of concept (POC) for improving the current method of locating nodes in shell files within the filetypes.lua file of andrewferrier/debugprint.nvim. Use tree-sitter query files for locating nodes instead of relying on the variable_type mechanism embedded in filetypes.lua.

Your implementation should meet the following criteria:

Implement the proof of concept for the shell file type only.

Use tree-sitter .query files to locate nodes instead of directly searching for variable_type in code.

Add fallbacks to the current mechanism if tree-sitter does not locate an appropriate node, ensuring seamless functionality even for shell files without tree-sitter grammar support.

Avoid impacting other file types or the general fallback behavior.

Use timber.nvim for inspiration as noted in the issue.

Deliver this as a minimal yet functional POC directly integrated into the repository, ensuring it only affects the shell file type. Test for consistent behavior with tree-sitter nodes, including edge cases where tree-sitter may fail.

This pull request was created from Copilot chat.

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

Copilot

Pull request overview

Adds a proof-of-concept Treesitter query-file mechanism to detect shell variable names under the cursor, using a queries/<lang>/debugprint.scm file (starting with bash) while keeping the existing node-based approach as a fallback.

Changes:

Added a queries/bash/debugprint.scm query capturing (variable_name) @variable for bash/sh/zsh variable detection.
Added find_variable_via_query(row, col) and made find_treesitter_variable try query-based capture matching first.
Expanded Treesitter identifier tests to cover query-based variable detection for bash and sh.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

File	Description
`lua/debugprint/utils/init.lua`	Introduces query-based variable lookup and wires it into existing Treesitter variable detection.
`queries/bash/debugprint.scm`	Defines a `debugprint` query for bash-family shells to capture variable names.
`tests/specs/treesitter.lua`	Adds test cases validating variable detection via the new query mechanism for bash/sh.

Copilot · 2026-03-04T12:51:20Z

+    -- Try query-file approach first (e.g. queries/bash/debugprint.scm).
+    -- This is the preferred mechanism for file types that provide a query file.
+    local cursor = vim.api.nvim_win_get_cursor(0)
+    local var = find_variable_via_query(cursor[1] - 1, cursor[2])
+    if var ~= nil then
+        return var


The PR description says the inline shell variable_name node-type check in filetypes.lua was replaced by the query file mechanism, but in the current code lua/debugprint/filetypes.lua still contains shell.find_treesitter_variable with a node:type() == "variable_name" check. Either update the PR description to reflect that this remains as a fallback, or remove/adjust the shell filetype config if the intent is to fully switch shell variable detection to the query-based approach.

It's already been removed!

Copilot · 2026-03-04T12:51:20Z

        local filename = support.init_file({
            "function x()",
            "    local xyz = 3",
            "end",
        }, "lua", 2, 9)

        support.feedkeys("g?v<BS><BS><BS>apple<CR>")

        support.check_lines({
            "function x()",
            "    local xyz = 3",
            "    print('DEBUGPRINT[1]: "
                .. filename
                .. ":2: apple=' .. vim.inspect(apple))",
            "end",
        })

        assert.are.same(vim.api.nvim_win_get_cursor(0), { 2, 9 })


The new query-based shell variable detection is tested for bash and sh, but the PR description also calls out zsh (same bash grammar). Adding a zsh case here would ensure the filetype→Treesitter language mapping still results in the queries/bash/debugprint.scm query being used for zsh buffers.

Yes, add a test for zsh too.

Added in commit 1a37ab7 — "standard (zsh) via query - same grammar as bash" test mirrors the sh test, confirming the zsh filetype resolves to the bash grammar and picks up queries/bash/debugprint.scm.

andrewferrier · 2026-03-04T12:52:26Z

@copilot OK, that's great! I also removed the shell configuration for find_treesitter_variable from filetypes.lua which you didn't remove.

Now, please add to this pull request the same thing for the js filetype, creating the equivalent of what's in find_treesitter_variable for it in filetypes.lua (and removing that function). Make sure to add some tests as applicable, ensuring they don't duplicate tests that are already present.

Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

Copilot · 2026-03-04T13:03:25Z

@copilot OK, that's great! I also removed the shell configuration for find_treesitter_variable from filetypes.lua which you didn't remove.

Now, please add to this pull request the same thing for th...

Done in commit f7c7bb4. Added queries/javascript/debugprint.scm with the equivalent captures ((member_expression property: (property_identifier)) @variable and (identifier) @variable) and removed find_treesitter_variable from the js table in filetypes.lua. Also updated find_variable_via_query to return the smallest matching capture at the cursor rather than the first — this ensures that when both identifier and member_expression overlap at the cursor (e.g. cursor on x in x.abc), the most specific node wins, preserving the original behaviour. Added a test for the plain JS identifier case; the existing member-expression test continues to cover that path.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

luarocks.org
- Triggering command: /usr/bin/lua5.1 /usr/bin/lua5.1 /usr/bin/luarocks install luacheck -Wl,--as-needed -Wl,-Bstatic /home/REDACTED/.rustup/toolchains/stable-x86_64-REDACTED-linux-gnu/lib/rustlib/x86_/tmp/cargo-installNJ7jOm/release/deps/stylua-1754b732f40e57fb.stylua.91752c909b681fea-cgu.14.rcgu.o c/lib.rs /home/REDACTED/.rustup/toolchains/stable-x86_64-REDACTED-linux-gnu/lib/rustlib/x86_/tmp/cargo-installNJ7jOm/release/deps/stylua-1754b732f40e57fb.394ki9rf8kimmkmu3wfgvz22f.rcgu.o /home/REDACTED/.rustup/toolchains/stable-x86_64-REDACTED-linux-gnu/lib/rustlib/x86_64-u�� /home/REDACTED/.rustup/toolchains/stable-x86_64-REDACTED-linux-gnu/lib/rustlib/x86_64-REDACTED-linux-gnu/lib/libpanic_unwind-35a18a1986ed2694.rlib /home/REDACTED/.rustup/toolchains/stable-x86_64-REDACTED-linux-gnu/lib/rustlib/x86_64-REDACTED-linux-gnu/lib/libobject-6d361988d8457911.rlib 64-u�� 64-REDACTED-linux-gnu/lib/libminiz_oxide-ec844042f1e20091.rlib 64-REDACTED-linux-gnu/lib/libadler2-fa28e789c10e1e7f.rlib lib/rustlib/x86_/tmp/cargo-installNJ7jOm/release/deps/derive_more_impl-55af7e5c2a9d4520.derive_m/tmp/rustcr550Kj/symbols.o ae8.serde_derivecc ae8.serde_derive-Wl,--version-script=/tmp/rustc07YUuh/list ae8.serde_derive-Wl,--no-undefined-version ae8.serde_derive-m64 (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

Configure Actions setup steps to set up my environment, which run before the firewall is enabled
Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

andrewferrier · 2026-03-04T13:08:33Z

        assert.equals(support.get_notify_message(), nil)
    end)

+    it("standard (javascript) via query - plain identifier", function()


Add at least one more test case to account for the member_expression in the treesitter query.

Added "standard (javascript) via query - member expression" in commit 1a37ab7. It places the cursor on the property value in obj.value = 10 (col 4), where only the member_expression capture matches, so the query returns obj.value.

Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

andrewferrier · 2026-03-04T19:26:35Z

+    end
+
+    -- Use the Treesitter language at the given position (supports injected languages)
+    local range = { row, col, row, col + 1 }


This should use the equivalent of get_effective_filetypes(). But refactor that function so we can get either filetypes or treesitter_languages from it so we can use it here.

Done in commit 7d0ebe4. Extracted get_treesitter_lang_at(row, col) — a shared local helper that calls parser:parse(true) (for embedded-language support), then parser:language_for_range({row,col,row,col}):lang() to return the language name string. Both find_variable_via_query and get_effective_filetypes now call this helper, removing the duplicated parser/language-detection logic.

andrewferrier · 2026-03-04T19:27:27Z

+
+    local root = trees[1]:root()
+
+    -- Find the smallest (most specific) capture containing the cursor position.


I think generally we want the largest match, not the smallest (identifier might be meaningless without the member_expression). So change this logic to do that.

Changed to largest in commit 7d0ebe4. The comparison is now if cur_size > best_size so that when both identifier and member_expression overlap at the cursor, the larger member_expression node wins and returns the full expression (e.g. obj.value) rather than just the bare identifier.

Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

andrewferrier · 2026-03-05T18:28:40Z

@copilot OK, this is looking great. Don't make any more changes to what you've done so far. However, finish the work by creating query files for lua, c, and zig, and remove the corresponding find_treesitter_variable funcs. Also remove the support for find_treesitter_variable generally. Make sure to add at least one test for each of lua, c, and zig. Also put these tests in a new test file called treesitter-queries.lua, and move the tests that have been created in this pull request into that file too.

…upport Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

Copilot · 2026-03-05T18:39:51Z

@copilot OK, this is looking great. Don't make any more changes to what you've done so far. However, finish the work by creating query files for lua, c, and zig, and remove the corresponding find_tre...

Done in commit 8f903d2. Here's what was done:

New query files:

queries/lua/debugprint.scm — (dot_index_expression) @variable + (identifier) @variable
queries/c/debugprint.scm — (field_expression) @variable + (identifier) @variable
queries/zig/debugprint.scm — (field_expression) @variable + (identifier) @variable

filetypes.lua: Removed find_treesitter_variable from lua, c, and zig configs.

find_treesitter_variable support removed generally:

Removed the find_treesitter_variable? field from FileTypeConfig in types.lua
Removed the per-filetype callback path from utils/init.lua (the local find_treesitter_variable now just calls find_variable_via_query and falls back to plain get_node_text for languages without a query file)
Removed the now-unused filetype_config parameter from M.get_variable_name and its call site in init.lua

New test file tests/specs/treesitter-queries.lua contains:

Moved from treesitter.lua: bash/sh/zsh "via query" + javascript "via query" (plain identifier + member expression) tests
New: lua (plain identifier + dot expression), c (plain identifier + field expression), zig (plain identifier + field expression) tests

andrewferrier · 2026-03-05T18:41:00Z

@copilot There are three tests still failing -

can handle treesitter identifiers non-identifier
double statement insertion variable (prompt)
delete lines command complex

…but no match Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

Copilot · 2026-03-05T18:48:58Z

@copilot There are three tests still failing -

can handle treesitter identifiers non-identifier
...

Fixed in commit e1fb832. The failures were all caused by the same root issue: when a language has a query file (e.g. Lua) but the cursor is not on a recognised capture (whitespace, comment, keyword), the fallback get_node_text was returning arbitrary node text, bypassing the user prompt.

The fix adds a guard in find_treesitter_variable: after find_variable_via_query returns nil, we check whether the language actually has a debugprint query file. If it does, we return nil immediately (triggering the prompt) rather than falling through to get_node_text. The get_node_text fallback is now only reached for languages that have no query file at all (Python, Ruby, PHP, etc.), preserving their existing behaviour.

andrewferrier · 2026-03-08T18:58:28Z

Squashed manually into 5541026

Initial plan

81ee045

Copilot AI assigned Copilot and andrewferrier Mar 4, 2026

Copilot started work on behalf of andrewferrier March 4, 2026 12:10 View session

feat: POC for tree-sitter query files for shell variable detection

ad2e59a

Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Add proof of concept for locating nodes in shell files~~ feat: POC for tree-sitter query files for shell variable detection Mar 4, 2026

Copilot finished work on behalf of andrewferrier March 4, 2026 12:21

andrewferrier marked this pull request as ready for review March 4, 2026 12:45

Copilot AI review requested due to automatic review settings March 4, 2026 12:45

Copilot started reviewing on behalf of andrewferrier March 4, 2026 12:45 View session

andrewferrier added 3 commits March 4, 2026 12:48

fix: Remove redundant find_treesitter_variable for shell

9800dc0

chore: Auto generate Vim docs

0d1fbac

test: Remove duplicate test

9fc1f35

Copilot AI reviewed Mar 4, 2026

View reviewed changes

Copilot started work on behalf of andrewferrier March 4, 2026 12:52 View session

feat: extend query-file POC to js filetype

f7c7bb4

Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

Copilot AI changed the title ~~feat: POC for tree-sitter query files for shell variable detection~~ feat: POC for tree-sitter query files for shell and JS variable detection Mar 4, 2026

Copilot finished work on behalf of andrewferrier March 4, 2026 13:04

Apply suggestion from @Copilot

6f13ea4

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

andrewferrier reviewed Mar 4, 2026

View reviewed changes

andrewferrier requested changes Mar 4, 2026

View reviewed changes

Copilot started work on behalf of andrewferrier March 4, 2026 13:09 View session

test: add zsh and JS member_expression query tests

1a37ab7

Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

Copilot finished work on behalf of andrewferrier March 4, 2026 13:15

andrewferrier reviewed Mar 4, 2026

View reviewed changes

andrewferrier requested changes Mar 4, 2026

View reviewed changes

Copilot started work on behalf of andrewferrier March 4, 2026 19:27 View session

refactor: extract get_treesitter_lang_at helper and use largest capture

7d0ebe4

Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

Copilot finished work on behalf of andrewferrier March 4, 2026 19:37

Copilot started work on behalf of andrewferrier March 5, 2026 18:28 View session

feat: add lua/c/zig query files and remove find_treesitter_variable s…

8f903d2

…upport Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

Copilot AI changed the title ~~feat: POC for tree-sitter query files for shell and JS variable detection~~ feat: tree-sitter query files for variable detection (bash, JS, Lua, C, Zig) Mar 5, 2026

Copilot finished work on behalf of andrewferrier March 5, 2026 18:40

Copilot started work on behalf of andrewferrier March 5, 2026 18:41 View session

fix: return nil from find_treesitter_variable when query file exists …

e1fb832

…but no match Co-authored-by: andrewferrier <107015+andrewferrier@users.noreply.github.com>

Copilot finished work on behalf of andrewferrier March 5, 2026 18:49

andrewferrier closed this Mar 8, 2026

andrewferrier deleted the copilot/add-poc-shell-node-locating branch March 8, 2026 18:58


		local root = trees[1]:root()

		-- Find the smallest (most specific) capture containing the cursor position.

Uh oh!

Conversation

Copilot AI commented Mar 4, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

andrewferrier Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Copilot AI Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

andrewferrier Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

andrewferrier commented Mar 4, 2026

Uh oh!

Copilot AI commented Mar 4, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

I tried to connect to the following addresses, but was blocked by firewall rules:

Uh oh!

andrewferrier Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

andrewferrier Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

andrewferrier Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 4, 2026

Choose a reason for hiding this comment

Uh oh!

andrewferrier commented Mar 5, 2026

Uh oh!

Copilot AI commented Mar 5, 2026

Uh oh!

andrewferrier commented Mar 5, 2026

Uh oh!

Copilot AI commented Mar 5, 2026

Uh oh!

andrewferrier commented Mar 8, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Copilot AI commented Mar 4, 2026 •

edited

Loading

Copilot AI commented Mar 4, 2026 •

edited

Loading