chore(docs): Add DEVELOPER.md

DEVELOPER.md

@@ -0,0 +1,162 @@
+# DEVELOPER.md
+
+## Versioning
+
+This library follows [Semantic Versioning](http://semver.org/).
+
+## Processes
+
+### Conventional Commit messages
+
+This repository uses tool [Release Please](https://github.com/googleapis/release-please) to create GitHub and PyPi releases. It does so by parsing your
+git history, looking for [Conventional Commit messages](https://www.conventionalcommits.org/),
+and creating release PRs.
+
+Learn more by reading [How should I write my commits?](https://github.com/googleapis/release-please?tab=readme-ov-file#how-should-i-write-my-commits)
+
+### Modifying existing classes
+When modifying any existing classes, ensure the required libraries are installed in "editable mode" using the command `pip install -e .` from your project's root directory.
+
+This allows your code to dynamically reflect any changes you make to the library, enabling efficient local testing of your new methods.
+
+## Dependencies
+
+The core dependencies needed for the working of this library are mentioned in `requirements.txt`, but it's version ranges along with the testing dependencies are set in `pyproject.toml`.
+
+## Testing
+
+### Formatting
+
+This repo has a lint checker test which is run on every PR  as set up in `.github/workflows/lint.yml`.
+You can run the formatter locally by following these steps.
+
+1.  Download all test dependencies
+    ```bash
+    pip install .[test]
+    ```
+
+2.  Run the black code formatter
+    ```bash
+    black .
+    ```
+
+3.  Run isort to sort all imports
+    ```bash
+    isort .
+    ```
+
+4.  Run mypy type checker
+    ```bash
+    mypy .
+    ```
+
+### Run tests locally
+
+1. Set environment variables for `INSTANCE_ID`, `DATABASE_ID`, `REGION`, `DB_USER`, `DB_PASSWORD`, `IAM_ACCOUNT`.
+
+2. Run pytest to automatically run all tests:
+
+    ```bash
+    pytest
+    ```
+
+Notes:
+
+* Tests use both IAM and built-in authentication.
+  * Learn how to set up a built-in databases user at [Cloud SQL built-in database authentication](https://cloud.google.com/sql/docs/postgres/built-in-authentication).
+  * Local tests will run against your `gcloud` credentials. Use `gcloud` to login with your personal account or a service account. This account will be used to run IAM tests. Learn how to set up access to the database at [Manage users with IAM database authentication](https://cloud.google.com/sql/docs/postgres/add-manage-iam-users). The "IAM_ACCOUNT" environment variable is also used to test authentication to override the local account. A personal account or a service account can be used for this test.
+  * You may need to grant access to the public schema for your new database user: `GRANT ALL ON SCHEMA public TO [email protected];`
+
+
+### CI Platform Setup
+
+Cloud Build is used to run tests against Google Cloud resources in test project: llama-index-cloud-sql-testing.
+Each test has a corresponding Cloud Build trigger, see [all triggers][triggers].
+These tests are registered as required tests in `.github/sync-repo-settings.yaml`.
+
+#### Trigger Setup
+
+Cloud Build triggers (for Python versions 3.9 to 3.11) were created with the following specs:
+
+```YAML
+name: pg-integration-test-pr-py39
+description: Run integration tests on PR for Python 3.9
+filename: integration.cloudbuild.yaml
+github:
+  name: llamaindex-cloud-sql-pg-python
+  owner: googleapis
+  pullRequest:
+    branch: .*
+    commentControl: COMMENTS_ENABLED_FOR_EXTERNAL_CONTRIBUTORS_ONLY
+ignoredFiles:
+  - docs/**
+  - .kokoro/**
+  - .github/**
+  - "*.md"
+substitutions:
+  _DATABASE_ID: <ADD_VALUE>
+  _INSTANCE_ID: <ADD_VALUE>
+  _REGION: us-central1
+  _VERSION: "3.9"
+```
+
+Use `gcloud builds triggers import --source=trigger.yaml` to create triggers via the command line
+
+#### Project Setup
+
+1. Create an Cloud SQL for PostgreSQL instance and database
+1. Setup Cloud Build triggers (above)
+
+#### Run tests with Cloud Build
+
+* Run integration test:
+
+    ```bash
+    gcloud builds submit --config integration.cloudbuild.yaml --region us-central1 --substitutions=_INSTANCE_ID=$INSTANCE_ID,_DATABASE_ID=$DATABASE_ID,_REGION=$REGION
+    ```
+
+#### Trigger
+
+To run Cloud Build tests on GitHub from external contributors, ie RenovateBot, comment: `/gcbrun`.
+
+#### Code Coverage
+Please make sure your code is fully tested. The Cloud Build integration tests are run with the `pytest-cov` code coverage plugin. They fail for PRs with a code coverage less than the threshold specified in `.coveragerc`.  If your file is inside the main module and should be ignored by code coverage check, add it to the `omit` section of `.coveragerc`.
+
+Check for code coverage report in any Cloud Build integration test log.
+Here is a breakdown of the report:
+- `Stmts`:  lines of executable code (statements).
+- `Miss`: number of lines not covered by tests.
+- `Branch`: branches of executable code (e.g an if-else clause may count as 1 statement but 2 branches; test for both conditions to have both branches covered).
+- `BrPart`: number of branches not covered by tests.
+- `Cover`: average coverage of files.
+- `Missing`: lines that are not covered by tests.
+
+## Documentation
+
+### LlamaIndex Integration Docs
+
+Google hosts documentation on LlamaIndex's site for individual integration pages:
+[Vector Stores][vs], [Document Store][docstore], [Index Store][indexstore], [Reader][reader], and [Chat Store][chatstore].
+
+Currently, manual PRs are made to the [LlamaIndex GitHub repo](https://github.com/run-llama/llama_index).
+
+### API Reference
+
+#### Build the documentation
+API docs are templated in the `docs/` directory.
+
+To test locally, run: `nox -s docs`
+
+The nox session, `docs`, is used to create HTML to publish to googleapis.dev
+The nox session, `docfx`, is used to create YAML to publish to CGC.
+
+#### Publish the documentation
+
+The kokoro docs pipeline runs when a new release is created. See `.kokoro/` for the release pipeline.
+
+[vs]: https://docs.llamaindex.ai/en/latest/examples/vector_stores/CloudSQLPgVectorStoreDemo/
+[chatstore]: https://docs.llamaindex.ai/en/latest/module_guides/storing/chat_stores/#google-cloud-sql-for-postgresql-chatstore
+[reader]: https://docs.llamaindex.ai/en/latest/examples/data_connectors/CloudSQLPgReaderDemo/
+[docstore]: https://docs.llamaindex.ai/en/latest/examples/docstore/CloudSQLPgDocstoreDemo/
+[indexstore]: https://docs.llamaindex.ai/en/latest/examples/docstore/CloudSQLPgDocstoreDemo/
+[triggers]: https://pantheon.corp.google.com/cloud-build/triggers?e=13802955&project=llamaindex-cloud-sql-testing