From fb0135febfec8f942923ed83ab1ebb85a2856fd3 Mon Sep 17 00:00:00 2001
From: Ben Russell <russellben@microsoft.com>
Date: Tue, 25 Aug 2026 13:59:46 -0500
Subject: [PATCH] Introduce config default pattern for perf tests

---
 .gitignore                                    |  3 +++
 BUILDGUIDE.md                                 | 20 ++++++++++---------
 ...oft.Data.SqlClient.PerformanceTests.csproj |  3 +++
 ...onfig.jsonc => runnerconfig.default.jsonc} |  2 +-
 4 files changed, 18 insertions(+), 10 deletions(-)
 rename src/Microsoft.Data.SqlClient/tests/PerformanceTests/{runnerconfig.jsonc => runnerconfig.default.jsonc} (99%)

diff --git a/.gitignore b/.gitignore
index 9289d0ab5f..674bef051d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -138,6 +138,9 @@ node_modules/
 **/config.json
 **/config.jsonc
 
+# Performance test runner config
+/src/Microsoft.Data.SqlClient/tests/PerformanceTests/runnerconfig.jsonc
+
 # Generated Milestone PR metadata files
 .milestone-prs/
 
diff --git a/BUILDGUIDE.md b/BUILDGUIDE.md
index 72daa88ea8..b42411806c 100644
--- a/BUILDGUIDE.md
+++ b/BUILDGUIDE.md
@@ -448,16 +448,19 @@ $ sqlcmd -S localhost -U sa -P password
 1> quit
 ```
 
-The default `runnerconfig.jsonc` expects a database named `sqlclient-perf-db`,
-but you may change the config to use any existing database.  The benchmarks
+The default `runnerconfig.default.jsonc` expects a database named
+`sqlclient-perf-db`, but you may change the generated `runnerconfig.jsonc`
+to use any existing database.  The benchmarks
 create and drop their own tables (typically prefixed with `perf_`) in this
 database; other existing tables are left untouched.
 
 ### Configure Runner
 
-Configure the benchmarks by editing the `runnerconfig.jsonc` file directly in the
+Configure the benchmarks by editing the `runnerconfig.jsonc` file in the
 `PerformanceTests` directory with an appropriate connection string and benchmark
-settings:
+settings. If the file does not exist, the build creates it from
+`runnerconfig.default.jsonc`; `runnerconfig.jsonc` is ignored by git so local
+connection strings and benchmark settings can stay local.
 
 ```json
 {
@@ -504,11 +507,10 @@ copy the file into the `artifacts` directory alongside the benchmark DLL.  By
 default, the benchmarks look for `runnerconfig.jsonc` in the same directory as
 the DLL.
 
-Optionally, to avoid polluting your git workspace and requiring a build after
-each config change, copy `runnerconfig.jsonc` to a new file, make your edits
-there, and then specify the new file with the RUNNER_CONFIG environment
-variable. The same approach works for `datatypes.json` via the
-`DATATYPES_CONFIG` environment variable.
+Optionally, to avoid requiring a build after each config change, copy
+`runnerconfig.jsonc` to a new file, make your edits there, and then specify the
+new file with the RUNNER_CONFIG environment variable. The same approach works
+for `datatypes.json` via the `DATATYPES_CONFIG` environment variable.
 
 PowerShell:
 
diff --git a/src/Microsoft.Data.SqlClient/tests/PerformanceTests/Microsoft.Data.SqlClient.PerformanceTests.csproj b/src/Microsoft.Data.SqlClient/tests/PerformanceTests/Microsoft.Data.SqlClient.PerformanceTests.csproj
index aced0f5bf0..4342e4c0fd 100644
--- a/src/Microsoft.Data.SqlClient/tests/PerformanceTests/Microsoft.Data.SqlClient.PerformanceTests.csproj
+++ b/src/Microsoft.Data.SqlClient/tests/PerformanceTests/Microsoft.Data.SqlClient.PerformanceTests.csproj
@@ -25,6 +25,9 @@
   </ItemGroup>
 
   <!-- Content files to copy to output directory -->
+  <Target Name="CopyRunnerConfig" BeforeTargets="Compile">
+    <Copy SourceFiles="runnerconfig.default.jsonc" DestinationFiles="runnerconfig.jsonc" Condition="!Exists('runnerconfig.jsonc')" />
+  </Target>
   <ItemGroup>
     <None Include="datatypes.json" CopyToOutputDirectory="PreserveNewest" />
     <None Include="runnerconfig.jsonc" CopyToOutputDirectory="PreserveNewest" />
diff --git a/src/Microsoft.Data.SqlClient/tests/PerformanceTests/runnerconfig.jsonc b/src/Microsoft.Data.SqlClient/tests/PerformanceTests/runnerconfig.default.jsonc
similarity index 99%
rename from src/Microsoft.Data.SqlClient/tests/PerformanceTests/runnerconfig.jsonc
rename to src/Microsoft.Data.SqlClient/tests/PerformanceTests/runnerconfig.default.jsonc
index 0ecc44e957..11a10d4666 100644
--- a/src/Microsoft.Data.SqlClient/tests/PerformanceTests/runnerconfig.jsonc
+++ b/src/Microsoft.Data.SqlClient/tests/PerformanceTests/runnerconfig.default.jsonc
@@ -1,4 +1,4 @@
-{
+{
     "ConnectionString": "Server=tcp:localhost; Integrated Security=true; Initial Catalog=sqlclient-perf-db;",
     // Enable this flag to enable managed SNI on Windows.
     "UseManagedSniOnWindows": false,