fix: list tables tools null fix by gRedHeadphone · Pull Request #2107 · googleapis/mcp-toolbox

gRedHeadphone · 2025-12-04T05:58:30Z

Description

Return empty list instead of null in list tables tools when no tables found

PR Checklist

Make sure you reviewed
CONTRIBUTING.md
Make sure to open an issue as a
bug/issue
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
Ensure the tests and linter pass
Code coverage does not decrease (if any source code was changed)
Appropriate docs were updated (if necessary)
Make sure to add ! if this involve a breaking change

🛠️ Fixes #2027

gemini-code-assist · 2025-12-04T05:58:47Z

Summary of Changes

Hello @gRedHeadphone, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses an inconsistency in the behavior of database table listing tools. Previously, these tools would return a null value when no tables were found, which could lead to unexpected behavior or require additional null checks in consuming code. The change standardizes the output to an empty list ([]) in such scenarios, improving the robustness and predictability of the API across different database integrations.

Highlights

Null Return Fix: Modified various database listing tools (ClickHouse, MSSQL, MySQL, PostgreSQL, Spanner) to return an empty list ([]) instead of null when no tables are found. This ensures consistent API behavior and prevents potential null pointer exceptions.
Test Updates: Updated existing tests for PostgreSQL, MySQL, and MSSQL list table functionalities to reflect the new expected behavior of returning an empty array instead of null when no tables match the criteria.

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Code Review

This pull request addresses an issue where various list-tables tools would return null instead of an empty list [] when no tables were found. The changes correctly modify slice initializations in Go from var s []T (which creates a nil slice) to s := []T{} (which creates an empty, non-nil slice). This ensures that the JSON response is consistently an array, improving API usability for clients. The corresponding tests have been updated to reflect this change in behavior. The fix is applied consistently across tools for ClickHouse, MSSQL, MySQL, PostgreSQL, and Spanner. The implementation is correct and follows Go best practices.

averikitsch · 2025-12-09T23:34:14Z

Can you look to see if MariaDB list tables needs to be updated?

gRedHeadphone · 2025-12-10T06:37:12Z

Can you look to see if MariaDB list tables needs to be updated?

@averikitsch It seems MariaDB uses MySQL source and tools, and I have updated MySQL list tables https://github.com/googleapis/genai-toolbox/pull/2107/files#diff-3a1dc16d3164a7f1344ee3ea73ab4505f57f15b9baf49ba095f4b3be6f08f84d so it should be fine

duwenxin99 · 2025-12-11T17:16:55Z

/gcbrun

🤖 I have created a release *beep* *boop* --- ## [0.23.0](v0.22.0...v0.23.0) (2025-12-11) ### ⚠ BREAKING CHANGES * **serverless-spark:** add URLs to create batch tool outputs * **serverless-spark:** add URLs to list_batches output * **serverless-spark:** add Cloud Console and Logging URLs to get_batch * **tools/postgres:** Add additional filter params for existing postgres tools ([#2033](#2033)) ### Features * **tools/postgres:** Add list-table-stats-tool to list table statistics. ([#2055](#2055)) ([78b02f0](78b02f0)) * **looker/tools:** Enhance dashboard creation with dashboard filters ([#2133](#2133)) ([285aa46](285aa46)) * **serverless-spark:** Add Cloud Console and Logging URLs to get_batch ([e29c061](e29c061)) * **serverless-spark:** Add URLs to create batch tool outputs ([c6ccf4b](c6ccf4b)) * **serverless-spark:** Add URLs to list_batches output ([5605eab](5605eab)) * **sources/mariadb:** Add MariaDB source and MySQL tools integration ([#1908](#1908)) ([3b40fea](3b40fea)) * **tools/postgres:** Add additional filter params for existing postgres tools ([#2033](#2033)) ([489117d](489117d)) * **tools/postgres:** Add list_pg_settings, list_database_stats tools for postgres ([#2030](#2030)) ([32367a4](32367a4)) * **tools/postgres:** Add new postgres-list-roles tool ([#2038](#2038)) ([bea9705](bea9705)) ### Bug Fixes * List tables tools null fix ([#2107](#2107)) ([2b45266](2b45266)) * **tools/mongodb:** Removed sortPayload and sortParams ([#1238](#1238)) ([c5a6daa](c5a6daa)) ### Miscellaneous Chores * **looker:** Upgrade to latest go sdk ([#2159](#2159)) ([78e015d](78e015d)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please). --------- Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com> Co-authored-by: Wenxin Du <117315983+duwenxin99@users.noreply.github.com>

🤖 I have created a release *beep* *boop* --- ## [0.23.0](v0.22.0...v0.23.0) (2025-12-11) ### ⚠ BREAKING CHANGES * **serverless-spark:** add URLs to create batch tool outputs * **serverless-spark:** add URLs to list_batches output * **serverless-spark:** add Cloud Console and Logging URLs to get_batch * **tools/postgres:** Add additional filter params for existing postgres tools ([#2033](#2033)) ### Features * **tools/postgres:** Add list-table-stats-tool to list table statistics. ([#2055](#2055)) ([78b02f0](78b02f0)) * **looker/tools:** Enhance dashboard creation with dashboard filters ([#2133](#2133)) ([285aa46](285aa46)) * **serverless-spark:** Add Cloud Console and Logging URLs to get_batch ([e29c061](e29c061)) * **serverless-spark:** Add URLs to create batch tool outputs ([c6ccf4b](c6ccf4b)) * **serverless-spark:** Add URLs to list_batches output ([5605eab](5605eab)) * **sources/mariadb:** Add MariaDB source and MySQL tools integration ([#1908](#1908)) ([3b40fea](3b40fea)) * **tools/postgres:** Add additional filter params for existing postgres tools ([#2033](#2033)) ([489117d](489117d)) * **tools/postgres:** Add list_pg_settings, list_database_stats tools for postgres ([#2030](#2030)) ([32367a4](32367a4)) * **tools/postgres:** Add new postgres-list-roles tool ([#2038](#2038)) ([bea9705](bea9705)) ### Bug Fixes * List tables tools null fix ([#2107](#2107)) ([2b45266](2b45266)) * **tools/mongodb:** Removed sortPayload and sortParams ([#1238](#1238)) ([c5a6daa](c5a6daa)) ### Miscellaneous Chores * **looker:** Upgrade to latest go sdk ([#2159](#2159)) ([78e015d](78e015d)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please). --------- Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com> Co-authored-by: Wenxin Du <117315983+duwenxin99@users.noreply.github.com> 466aef0

🤖 I have created a release *beep* *boop* --- ## [0.23.0](googleapis/mcp-toolbox@v0.22.0...v0.23.0) (2025-12-11) ### ⚠ BREAKING CHANGES * **serverless-spark:** add URLs to create batch tool outputs * **serverless-spark:** add URLs to list_batches output * **serverless-spark:** add Cloud Console and Logging URLs to get_batch * **tools/postgres:** Add additional filter params for existing postgres tools ([googleapis#2033](googleapis#2033)) ### Features * **tools/postgres:** Add list-table-stats-tool to list table statistics. ([googleapis#2055](googleapis#2055)) ([78b02f0](googleapis@78b02f0)) * **looker/tools:** Enhance dashboard creation with dashboard filters ([googleapis#2133](googleapis#2133)) ([285aa46](googleapis@285aa46)) * **serverless-spark:** Add Cloud Console and Logging URLs to get_batch ([e29c061](googleapis@e29c061)) * **serverless-spark:** Add URLs to create batch tool outputs ([c6ccf4b](googleapis@c6ccf4b)) * **serverless-spark:** Add URLs to list_batches output ([5605eab](googleapis@5605eab)) * **sources/mariadb:** Add MariaDB source and MySQL tools integration ([googleapis#1908](googleapis#1908)) ([3b40fea](googleapis@3b40fea)) * **tools/postgres:** Add additional filter params for existing postgres tools ([googleapis#2033](googleapis#2033)) ([489117d](googleapis@489117d)) * **tools/postgres:** Add list_pg_settings, list_database_stats tools for postgres ([googleapis#2030](googleapis#2030)) ([32367a4](googleapis@32367a4)) * **tools/postgres:** Add new postgres-list-roles tool ([googleapis#2038](googleapis#2038)) ([bea9705](googleapis@bea9705)) ### Bug Fixes * List tables tools null fix ([googleapis#2107](googleapis#2107)) ([2b45266](googleapis@2b45266)) * **tools/mongodb:** Removed sortPayload and sortParams ([googleapis#1238](googleapis#1238)) ([c5a6daa](googleapis@c5a6daa)) ### Miscellaneous Chores * **looker:** Upgrade to latest go sdk ([googleapis#2159](googleapis#2159)) ([78e015d](googleapis@78e015d)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please). --------- Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com> Co-authored-by: Wenxin Du <117315983+duwenxin99@users.noreply.github.com> 466aef0

## Description Return empty list instead of null in list tables tools when no tables found ## PR Checklist - [x] Make sure you reviewed [CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md) - [x] Make sure to open an issue as a [bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose) before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea - [x] Ensure the tests and linter pass - [x] Code coverage does not decrease (if any source code was changed) - [x] Appropriate docs were updated (if necessary) - [x] Make sure to add `!` if this involve a breaking change 🛠️ Fixes #2027 --------- Co-authored-by: Averi Kitsch <akitsch@google.com>

🤖 I have created a release *beep* *boop* --- ## [0.23.0](v0.22.0...v0.23.0) (2025-12-11) ### ⚠ BREAKING CHANGES * **serverless-spark:** add URLs to create batch tool outputs * **serverless-spark:** add URLs to list_batches output * **serverless-spark:** add Cloud Console and Logging URLs to get_batch * **tools/postgres:** Add additional filter params for existing postgres tools ([#2033](#2033)) ### Features * **tools/postgres:** Add list-table-stats-tool to list table statistics. ([#2055](#2055)) ([78b02f0](78b02f0)) * **looker/tools:** Enhance dashboard creation with dashboard filters ([#2133](#2133)) ([285aa46](285aa46)) * **serverless-spark:** Add Cloud Console and Logging URLs to get_batch ([e29c061](e29c061)) * **serverless-spark:** Add URLs to create batch tool outputs ([c6ccf4b](c6ccf4b)) * **serverless-spark:** Add URLs to list_batches output ([5605eab](5605eab)) * **sources/mariadb:** Add MariaDB source and MySQL tools integration ([#1908](#1908)) ([3b40fea](3b40fea)) * **tools/postgres:** Add additional filter params for existing postgres tools ([#2033](#2033)) ([489117d](489117d)) * **tools/postgres:** Add list_pg_settings, list_database_stats tools for postgres ([#2030](#2030)) ([32367a4](32367a4)) * **tools/postgres:** Add new postgres-list-roles tool ([#2038](#2038)) ([bea9705](bea9705)) ### Bug Fixes * List tables tools null fix ([#2107](#2107)) ([2b45266](2b45266)) * **tools/mongodb:** Removed sortPayload and sortParams ([#1238](#1238)) ([c5a6daa](c5a6daa)) ### Miscellaneous Chores * **looker:** Upgrade to latest go sdk ([#2159](#2159)) ([78e015d](78e015d)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please). --------- Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com> Co-authored-by: Wenxin Du <117315983+duwenxin99@users.noreply.github.com>

## Description Return empty list instead of null in list tables tools when no tables found ## PR Checklist - [x] Make sure you reviewed [CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md) - [x] Make sure to open an issue as a [bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose) before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea - [x] Ensure the tests and linter pass - [x] Code coverage does not decrease (if any source code was changed) - [x] Appropriate docs were updated (if necessary) - [x] Make sure to add `!` if this involve a breaking change 🛠️ Fixes googleapis#2027 --------- Co-authored-by: Averi Kitsch <akitsch@google.com>

🤖 I have created a release *beep* *boop* --- ## [0.23.0](googleapis/mcp-toolbox@v0.22.0...v0.23.0) (2025-12-11) ### ⚠ BREAKING CHANGES * **serverless-spark:** add URLs to create batch tool outputs * **serverless-spark:** add URLs to list_batches output * **serverless-spark:** add Cloud Console and Logging URLs to get_batch * **tools/postgres:** Add additional filter params for existing postgres tools ([googleapis#2033](googleapis#2033)) ### Features * **tools/postgres:** Add list-table-stats-tool to list table statistics. ([googleapis#2055](googleapis#2055)) ([78b02f0](googleapis@78b02f0)) * **looker/tools:** Enhance dashboard creation with dashboard filters ([googleapis#2133](googleapis#2133)) ([285aa46](googleapis@285aa46)) * **serverless-spark:** Add Cloud Console and Logging URLs to get_batch ([e29c061](googleapis@e29c061)) * **serverless-spark:** Add URLs to create batch tool outputs ([c6ccf4b](googleapis@c6ccf4b)) * **serverless-spark:** Add URLs to list_batches output ([5605eab](googleapis@5605eab)) * **sources/mariadb:** Add MariaDB source and MySQL tools integration ([googleapis#1908](googleapis#1908)) ([3b40fea](googleapis@3b40fea)) * **tools/postgres:** Add additional filter params for existing postgres tools ([googleapis#2033](googleapis#2033)) ([489117d](googleapis@489117d)) * **tools/postgres:** Add list_pg_settings, list_database_stats tools for postgres ([googleapis#2030](googleapis#2030)) ([32367a4](googleapis@32367a4)) * **tools/postgres:** Add new postgres-list-roles tool ([googleapis#2038](googleapis#2038)) ([bea9705](googleapis@bea9705)) ### Bug Fixes * List tables tools null fix ([googleapis#2107](googleapis#2107)) ([2b45266](googleapis@2b45266)) * **tools/mongodb:** Removed sortPayload and sortParams ([googleapis#1238](googleapis#1238)) ([c5a6daa](googleapis@c5a6daa)) ### Miscellaneous Chores * **looker:** Upgrade to latest go sdk ([googleapis#2159](googleapis#2159)) ([78e015d](googleapis@78e015d)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please). --------- Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com> Co-authored-by: Wenxin Du <117315983+duwenxin99@users.noreply.github.com>

🤖 I have created a release *beep* *boop* --- ## [0.23.0](googleapis/mcp-toolbox@v0.22.0...v0.23.0) (2025-12-11) ### ⚠ BREAKING CHANGES * **serverless-spark:** add URLs to create batch tool outputs * **serverless-spark:** add URLs to list_batches output * **serverless-spark:** add Cloud Console and Logging URLs to get_batch * **tools/postgres:** Add additional filter params for existing postgres tools ([#2033](googleapis/mcp-toolbox#2033)) ### Features * **tools/postgres:** Add list-table-stats-tool to list table statistics. ([#2055](googleapis/mcp-toolbox#2055)) ([78b02f0](googleapis/mcp-toolbox@78b02f0)) * **looker/tools:** Enhance dashboard creation with dashboard filters ([#2133](googleapis/mcp-toolbox#2133)) ([285aa46](googleapis/mcp-toolbox@285aa46)) * **serverless-spark:** Add Cloud Console and Logging URLs to get_batch ([e29c061](googleapis/mcp-toolbox@e29c061)) * **serverless-spark:** Add URLs to create batch tool outputs ([c6ccf4b](googleapis/mcp-toolbox@c6ccf4b)) * **serverless-spark:** Add URLs to list_batches output ([5605eab](googleapis/mcp-toolbox@5605eab)) * **sources/mariadb:** Add MariaDB source and MySQL tools integration ([#1908](googleapis/mcp-toolbox#1908)) ([3b40fea](googleapis/mcp-toolbox@3b40fea)) * **tools/postgres:** Add additional filter params for existing postgres tools ([#2033](googleapis/mcp-toolbox#2033)) ([489117d](googleapis/mcp-toolbox@489117d)) * **tools/postgres:** Add list_pg_settings, list_database_stats tools for postgres ([#2030](googleapis/mcp-toolbox#2030)) ([32367a4](googleapis/mcp-toolbox@32367a4)) * **tools/postgres:** Add new postgres-list-roles tool ([#2038](googleapis/mcp-toolbox#2038)) ([bea9705](googleapis/mcp-toolbox@bea9705)) ### Bug Fixes * List tables tools null fix ([#2107](googleapis/mcp-toolbox#2107)) ([2b45266](googleapis/mcp-toolbox@2b45266)) * **tools/mongodb:** Removed sortPayload and sortParams ([#1238](googleapis/mcp-toolbox#1238)) ([c5a6daa](googleapis/mcp-toolbox@c5a6daa)) ### Miscellaneous Chores * **looker:** Upgrade to latest go sdk ([#2159](googleapis/mcp-toolbox#2159)) ([78e015d](googleapis/mcp-toolbox@78e015d)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please). --------- Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com> Co-authored-by: Wenxin Du <117315983+duwenxin99@users.noreply.github.com>

fix: list tables tools null fix

fa1be0a

gRedHeadphone requested a review from a team December 4, 2025 05:58

blunderbuss-gcf Bot assigned duwenxin99 Dec 4, 2025

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Merge branch 'main' into list-table-null-fix

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gRedHeadphone assigned averikitsch and unassigned duwenxin99 Dec 4, 2025

gRedHeadphone added 2 commits December 5, 2025 10:37

Merge branch 'main' into list-table-null-fix

332c841

fix: update run mysql list table test

4856ba7

gRedHeadphone force-pushed the list-table-null-fix branch from 29f43dc to 4856ba7 Compare December 5, 2025 07:45

averikitsch approved these changes Dec 9, 2025

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Merge branch 'main' into list-table-null-fix

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averikitsch enabled auto-merge (squash) December 9, 2025 22:14

averikitsch added the release candidate Use label to signal PR should be included in the next release. label Dec 9, 2025

Merge branch 'main' into list-table-null-fix

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duwenxin99 added the tests: run Label to trigger Github Action tests. label Dec 11, 2025

github-actions Bot removed the tests: run Label to trigger Github Action tests. label Dec 11, 2025

duwenxin99 and others added 3 commits December 11, 2025 15:26

update mariadb integration test want

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Merge branch 'main' into list-table-null-fix

f3c1c06

update mariadb test

3326e4c

averikitsch merged commit 2b45266 into main Dec 11, 2025
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averikitsch deleted the list-table-null-fix branch December 11, 2025 20:58

release-please Bot mentioned this pull request Dec 11, 2025

chore(main): release 0.23.0 #2138

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BrewTestBot mentioned this pull request Dec 11, 2025

mcp-toolbox 0.23.0 Homebrew/homebrew-core#258282

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github-actions Bot mentioned this pull request Feb 20, 2026

feat(tools/looker): Enable Get All Lookml Tests tool for Looker Anthrino/genai-toolbox#3

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fix: list tables tools null fix#2107

fix: list tables tools null fix#2107
averikitsch merged 9 commits into
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gRedHeadphone commented Dec 4, 2025

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