GODRIVER-3891 Remove the operation.Command type.

[matthewdale]

GODRIVER-3891

Summary

• Completely remove the operation.Command type.
• Use the driver.Operation type directly in processRunCommand in the mongo package.
• Create a runCommand function specific to the x/mongo/driver/auth package.
• Create an executeCommand function specific to the x/mongo/driver/integration package.

Background & Motivation

Part of a larger effort to reduce unnecessary code by removing the x/mongo/driver/operation package.

Unlike other types in the x/mongo/driver/operation package, the operation.Command type does not provide any command logic, but is a thin wrapper around driver.Operation, only adding cursor response parsing for a single caller (mongo.RunCommandCursor). This PR completely removes the operation.Command type, replacing it with direct use of driver.Operation.

[mongodb-drivers-pr-bot]

API Change Report

./v2/x/mongo/driver/operation

incompatible changes

Command: removed
NewCommand: removed
NewCursorCommand: removed

[mongodb-drivers-pr-bot]

🧪 Performance Results

Commit SHA: e2235f4

The following benchmark tests for version 6a55a8c98243090007aba576 had statistically significant changes (i.e., |z-score| > 1.96):

Benchmark	Measurement	% Change	Patch Value	Stable Region	H-Score	Z-Score
BenchmarkSingleRunCommand	allocated_bytes_per_op	-0.2017	12208.0000	Avg: 12232.6744 Med: 12234.0000 Stdev: 6.6835	0.8650	-3.6918

For a comprehensive view of all microbenchmark results for this PR's commit, please check out the Evergreen perf task for this patch.

[Copilot]

Pull request overview

This PR removes the operation.Command wrapper type from x/mongo/driver/operation and replaces its usage with direct driver.Operation construction. The goal is to reduce indirection in the ongoing effort to remove the x/mongo/driver/operation package where it provides minimal value.

Changes:

• Deleted x/mongo/driver/operation/command.go and replaced call sites with direct driver.Operation usage.
• Refactored mongo.Database’s RunCommand paths to build/return a *driver.Operation and attach response processing in RunCommand / RunCommandCursor.
• Added package-local command helpers for auth (runCommand) and integration tests (executeCommand, dropDatabase) to replace the removed wrapper.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
x/mongo/driver/operation/command.go	Removes the operation.Command type entirely.
x/mongo/driver/integration/main_test.go	Adds executeCommand helper and updates integration test helpers to use driver.Operation directly.
x/mongo/driver/integration/compressor_test.go	Switches serverStatus execution to executeCommand (removes operation.Command usage).
x/mongo/driver/auth/x509.go	Routes X509 auth command execution through the new auth-local runCommand helper.
x/mongo/driver/auth/sasl.go	Introduces auth-local runCommand helper and replaces operation.Command usage in SASL flows.
mongo/database.go	Refactors RunCommand/RunCommandCursor to construct and execute driver.Operation directly and handle cursor parsing via ProcessResponseFn.
internal/integtest/integtest.go	Adds dropDatabase helper implemented with driver.Operation and updates topology setup to use it.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.