Add customization for the Gemini Code Assist review bot (flutter#9774)

Author: kenzieschmoll

.gemini/config.yaml

@@ -0,0 +1,28 @@
+# Customize Gemini Code Assist behavior for DevTools.
+#
+# Schema: https://developers.google.com/gemini-code-assist/docs/customize-repo-review#config.yaml-schema
+# Based on Flutter config: https://github.com/flutter/flutter/blob/master/.gemini/config.yaml
+
+# Minimize verbosity.
+have_fun: false
+
+code_review:
+  # (DEFAULT) - Include field in the config for easy shut off if needed.
+  disable: false
+  # LOW, MEDIUM, HIGH or CRITICAL.
+  comment_severity_threshold: MEDIUM
+  # (DEFAULT) -1 is unlimited.
+  max_review_comments: -1
+  pull_request_opened:
+    # (DEFAULT) Explicitly set help to false in case the default changes in the
+    # future, as having a help message on every PR would be spammy.
+    help: false
+    # These tend to be verbose, and since we expect PR authors to clearly
+    # describe their PRs this would be at best duplicative.
+    summary: false
+    # Avoid comments on draft PRs.
+    include_drafts: false 
+
+ignore_patterns:
+  # Ignore third party files by default
+  - "**/third_party/**" 

.gemini/styleguide.md

@@ -0,0 +1,51 @@
+# DevTools Style Guide for Gemini Code Assist
+
+This style guide outlines the coding conventions for the DevTools repository to help Gemini Code Assist provide effective code reviews. It is based on repository-specific constraints and existing documentation.
+
+**Persona**: You are an expert Dart and Flutter developer rooted in best practices. Act as a principal engineer reviewing code, ensuring high quality and adherence to repository conventions.
+
+## 1. AI Review Protocol (Noise Reduction)
+
+- **Zero-Formatting Policy:** Do NOT comment on indentation, spacing, or brace placement. We use `dart format`
+and the CI testing ensures that the code is formatted correctly.
+- **Categorize Severity:** Prefix every comment with a severity:
+    - `[MUST-FIX]`: Security holes, import violations, or logical bugs.
+    - `[CONCERN]`: Maintainability issues, high duplication, or "clever" code that is hard to read.
+    - `[NIT]`: Idiomatic improvements or minor naming suggestions.
+- **Focus:** Prioritize logic, performance on the UI thread, and architectural consistency.
+- **No Empty Praise:** Do not leave "Looks good" or "Nice change" comments. If there are no issues, leave no comments.
+- **Copyright Headers:** Ensure all new files have a proper copyright header with the current year. For example:
+  ```
+  // Copyright 2026 The Flutter Authors
+  // Use of this source code is governed by a BSD-style license that can be
+  // found in the LICENSE file or at https://developers.google.com/open-source/licenses/bsd.
+  ```
+  Flag missing copyright headers as `[MUST-FIX]`.
+
+## 2. Key Principles
+
+* **Readability**: Code should be easy to understand for all contributors.
+* **Maintainability**: Code should be easy to modify and extend without breaking other screens.
+* **Consistency**: Adhering to consistent style across all DevTools packages improves collaboration and reduces errors.
+* **Code Reuse**: Use shared primitives and components rather than recreating them from scratch.
+* **Testing**: All changes should include automated tests to ensure correctness and prevent regressions.
+
+## 3. Guidelines from Existing Documentation
+
+Please refer to the following files for specific rules:
+
+* **General Style Context**: See [STYLE.md](STYLE.md) for rules on:
+  * Getter and setter order.
+  * Naming for typedefs and function variables.
+  * Overriding equality.
+  * Windows/POSIX path handling conventions.
+  * Default text styles.
+* **Repository Constraints**: See [AGENTS.md](AGENTS.md) for rules on:
+  * Constraints on `packages/devtools_shared` (no Flutter dependency).
+  * Import restrictions (no importing `devtools_app.dart` from `src/`).
+  * Published packages management (CHANGELOGs, versions, breaking changes).
+  * Code quality (DRY, Meaningful Naming).
+  * Strict avoidance of raw values in UI (use named constants).
+  * Usage of established themes and text styles.
+  * Usage of shared components and utilities.
+  * Widget structure (avoiding long build methods, widgets vs methods).

.gitignore

@@ -43,9 +43,6 @@ DEPENDENCIES.md
 **/logs/**
 *.stager_app.g.dart
 
-# Ignore Gemini logs
-**/.gemini/
-
 # Ignore VS code workspaces that may be configured per-user
 *.code-workspace
 

AGENTS.md

@@ -8,20 +8,33 @@ Follow these rules when working in this repository.
 -   **`packages/devtools_shared`**: Never introduce a Flutter dependency or a dependency on web-only Dart libraries.
 -   **Imports**: Never import `packages/devtools_app/lib/devtools_app.dart` in code under `packages/devtools_app/lib/src/`. It is acceptable in test code.
 
+### Published Packages (`packages/devtools_shared`, `packages/devtools_app_shared`, `packages/devtools_extensions`)
+- Document file changes in the respective `CHANGELOG.md` files.
+- Ensure version numbers in `pubspec.yaml` are updated accordingly for required changes.
+- Ensure no breaking changes are introduced. If introduced, they must be intentional and documented.
+- The published packages should not depend on unpublished packages like `packages/devtools_app` and `packages/devtools_test`.
+
 ### Code Style
 -   **Style Guide**: Follow the DevTools style guide in [STYLE.md](STYLE.md).
 -   **Formatting & Analysis**: Always ensure code is formatted properly and has no analysis errors or warnings before completing a task.
 
-## Running Tests
+### Code Quality & Maintainability
+-   **DRY (Don't Repeat Yourself)**: Identify blocks of code that are 90%+ identical to existing utility methods in this repo and flag them for duplication.
+-   **Meaningful Naming**: Variables should describe their intent (e.g., `timeoutInMs` instead of `t`).
+-   **Descriptive Pull Request**: Contributors should include the information recommended in the pull request template (in `.github/PULL_REQUEST_TEMPLATE.md`).
+
+## Documentation
+- All public members should have documentation.
+- **Answer your own questions**: If you have a question, find the answer, and then document it where you first looked.
+- **Documentation should be useful**: Explain the *why* and the *how*.
+- **Introduce terms**: Assume the reader does not know everything. Link to definitions.
+- Use `///` for public-quality documentation, even on private members.
 
+## Running Tests
 -   **Standard Packages**: Run unit and widget tests with `flutter test`.
 -   **`packages/devtools_shared`**: Run tests with `dart test`.
 -   **Integration Tests**: Refer to the [Integration Test README](packages/devtools_app/integration_test/README.md) for instructions on running integration tests.
 
-## Tooling Best Practices
-
--   **MCP Tools**: Prefer using MCP server tools over shell commands whenever possible.
-
 ## UI Development Guidelines
 
 ### Constants and Magic Values
@@ -34,3 +47,6 @@ Follow these rules when working in this repository.
 ### Code Reuse
 -   **Use Shared Components & Utils**: Prefer using reusable components from `shared/ui/` (such as `packages/devtools_app/lib/src/shared/ui/common_widgets.dart`), primitives from `shared/primitives/`, and utilities from `shared/utils/` rather than creating things from scratch.
 
+### Helper Widgets and Methods
+-   **Avoid Long Build Methods**: Use separate helper widgets instead of writing excessively long build methods to keep the structure clear.
+-   **Prefer Widgets Over Methods**: Create small, composable helper widgets rather than helper methods that return a widget at build time. This improves readability and allows Flutter to optimize tree updates better.

STYLE.md

@@ -6,14 +6,14 @@ found in the LICENSE file or at https://developers.google.com/open-source/licens
 # DevTools style guide
 
 We fully follow [Effective Dart](https://dart.dev/effective-dart)
-and some items of
-[Style guide for Flutter repo](https://github.com/flutter/flutter/blob/master/docs/contributing/Style-guide-for-Flutter-repo.md):
+and certain guidelines from the
+[Flutter repository style guide](https://github.com/flutter/flutter/blob/master/docs/contributing/Style-guide-for-Flutter-repo.md):
 
 ## Order of getters and setters
 
-When an object owns and exposes a (listenable) value,
-more complicated than just public field
-we declare the related class members always in the same order,
+When an object owns and exposes a (listenable) value
+that is more complex than a simple public field,
+we always declare the related class members in the same order,
 without new lines separating the members,
 in compliance with
 [Flutter repo style guide](https://github.com/flutter/flutter/blob/master/docs/contributing/Style-guide-for-Flutter-repo.md#order-other-class-members-in-a-way-that-makes-sense):
@@ -41,10 +41,10 @@ converted to paths when required to interact with the file system.
 
 Additionally:
 
-- `Uri.parse()` should not be used for converting file paths to URIs, instead
-  `Uri.file()` should be used
-- `Uri.path` should not be used for extracting a file path from a URI, instead
-  `uri.toFilePath()` should be used
+- `Uri.parse()` should not be used for converting file paths to URIs; instead,
+  `Uri.file()` should be used.
+- `Uri.path` should not be used for extracting a file path from a URI; instead,
+  `uri.toFilePath()` should be used.
 - In code compiled to run in the browser, `Uri.file()` and `uri.toFilePath()`
   will assume POSIX-style paths even on Windows, so care should be taken to
   handle these correctly (if possible, avoid converting between URIs and file