Cosmos Pre Commit Validation Agent Skill

Cosmos SDK Pre-Commit Checks

When to use this skill

Use this skill when:

• Reviewing or validating changes in the Cosmos SDK
• Running pre-commit checks locally before pushing
• Performing focused code review on sdk/cosmos/**

Behavior

Follow these steps strictly:

• Determine the target path:
• If the scope argument is specified and is not equal (case-insensitive) to all or *, set the target path to sdk/cosmos/<scope> (for example, if scope is azure_data_cosmos, use sdk/cosmos/azure_data_cosmos as the target path).
• Otherwise, set the target path to sdk/cosmos.

• Determine file scope:
• If changed-only is true (the default), restrict scanning to .rs files that differ between the current local branch and main. Use git diff --name-only main -- <target path> (and include per-crate tests/ directories) to obtain the list. Only .rs files in the result set are scanned; all other files are skipped.
• If changed-only is false, scan all .rs files under the target path(s).
• In both modes, skip files in generated/ subdirectories — these are produced by external tools and must never be modified.

• Validate using the Pre-Completion Validation Checklist in sdk/cosmos/AGENTS.md:
• Formatting checks
• Build succeeds for affected crates
• Clippy lints pass for affected crates, with warnings treated as errors (-D warnings) to match CI behavior.

Run clippy with RUSTFLAGS=-D warnings set:

• Bash: RUSTFLAGS='-D warnings' cargo clippy -p <crate> --all-features --all-targets
• PowerShell: $env:RUSTFLAGS='-D warnings'; cargo clippy -p <crate> --all-features --all-targets; $env:RUSTFLAGS=$null
• Re-run formatting after any auto-fix: if auto-fix is true and clippy or other tools modified files,

re-run cargo fmt to ensure the auto-fixed code is properly formatted (e.g., cargo clippy --fix can

leave trailing blank lines when removing unused imports).

• Documentation builds successfully where applicable
• Spell check (cspell): CI runs cspell on all changed files using the config at .vscode/cspell.json

with the Cosmos-specific dictionary at sdk/cosmos/.dict.txt. Run locally with:

npx cspell lint --config .vscode/cspell.json --no-must-find-files <target path>/**

If auto-fix is true and unknown words are legitimate (e.g., API type names, technical terms),

add them to sdk/cosmos/.dict.txt.

• Unit and emulator tests relevant to the touched modules and crates
• CI-gated tests: Tests gated by test_category (e.g., emulator, multi-write) are always compiled but are ignored at runtime unless the corresponding cfg is set via RUSTFLAGS.

This means cargo check --tests and cargo test will compile these tests without any special flags, so build errors are caught locally.

RUSTFLAGS is only needed when you want to actually run the tests:

• RUSTFLAGS='--cfg test_category="emulator"' cargo test -p azure_data_cosmos --features fault_injection,key_auth --tests
• RUSTFLAGS='--cfg test_category="multi_write"' cargo test -p azure_data_cosmos --features fault_injection,key_auth --tests

On Windows (PowerShell), set the env var first: $env:RUSTFLAGS='--cfg test_category="emulator"' then run the cargo test command, and clear it afterwards with $env:RUSTFLAGS=$null.

These tests require a live Cosmos DB emulator or multi-region account to run.

If scope targets a specific crate other than azure_data_cosmos, skip these checks.

• Report results:
• Summarize failures concisely
• Include exact file paths and commands to reproduce
• Do NOT auto-fix unless auto-fix argument is true

Notes

• Never run repo-wide checks outside sdk/cosmos
• Avoid long-running integration tests unless explicitly requested