Make STS2 SQLite driver opt-in

[Karl Burtram (kburtram)]

Why

STS2's SQLite driver is a non-production local/test component (Production=false), but the product Bootstrap project referenced it unconditionally. A portable (RID-less) publish therefore pulled Microsoft.Data.Sqlite, SQLitePCLRaw, and native e_sqlite3 assets for every supported runtime into the production bundle. RID-specific publishes select one native asset, which is why their size stayed roughly flat while the portable archive jumped sharply.

What changed

• Make IncludeSts2SqliteDriver default to false at the product composition root.
• Compile and register the SQLite driver only when that property is explicitly true.
• Keep SQLite unit/contract coverage through the test project's direct driver reference.
• Build the SQLite E2E subject into isolated bin/obj paths so it cannot overwrite or contaminate the default product subject.
• Add an architecture guard and document the production/default versus local/test dependency boundary.

This leaves the production sqlclient driver and STS2 activation behavior unchanged. Local experiments can opt in explicitly:

dotnet publish src/Microsoft.SqlTools.ServiceLayer/Microsoft.SqlTools.ServiceLayer.csproj `
  -p:IncludeSts2SqliteDriver=true

Measured package impact

Release-mode publishes from this branch:

Output	Default graph	SQLite opt-in graph	Default reduction
Portable ZIP	67,905,810 bytes	101,894,220 bytes	33,988,410 bytes (32.4 MiB, 33.4%)
win-x64 self-contained, uncompressed	285,030,656 bytes	287,276,602 bytes	2,245,946 bytes (2.1 MiB)

The default outputs contain zero SQLite files or .deps.json entries. The opt-in portable output contains 36 SQLite-related files, including 29 native assets spanning Android, browser, iOS, Linux, macOS, and Windows; the opt-in win-x64 output contains only the matching e_sqlite3.dll plus the managed driver files.

Validation

• STS2 unit/contract/architecture suite with a required live SQL Server: 507 passed.
• STS2 process E2E matrix (default product subject plus isolated SQLite opt-in subject): 7 passed.
• Legacy ServiceLayer unit suite: 1,945 passed.
• Legacy ServiceLayer live SQL integration suite: 446 passed / 22 skipped / 0 failed (468 total).
• vscode-mssql dev/refactor: build passed; lint passed after normalizing three pre-existing CRLF-only files in the disposable validation clone; VS Code unit suite 5,785 passed / 13 skipped; online VSIX packaging passed.
• kburtram/perftest: build and typecheck passed; 323 tests passed / 15 optional central-store tests skipped because that endpoint was unavailable.
• Cross-repository live STS2 backend-shape validation against vscode-mssql dev/refactor: 10/10 passed with the default graph and the identical 10/10 passed with the SQLite-opt-in graph. The matrix covered 100k narrow rows, 300-column rows, large cells, blob/XML, forced spill/copy, 100 result sets, spatial, vector, cancellation, and disposal.

All cross-repository checks used isolated clones; the active refactor worktrees were not modified.

[Copilot]

Pull request overview

This PR makes the STS2 SQLite driver truly opt-in at the Bootstrap (composition root) level to prevent non-production SQLite dependencies and native assets from inflating the default/portable ServiceLayer publish outputs. It also updates tests and documentation to enforce and explain the new production-default vs local/test boundary, including building a separate SQLite-enabled E2E “subject” into isolated output paths.

Changes:

• Make IncludeSts2SqliteDriver default to false and conditionally reference/compile the SQLite driver only when explicitly enabled.
• Update STS2 E2E harness to support spawning an isolated SQLite-enabled ServiceLayer build, and add assertions that default subjects contain no SQLite assets.
• Update generated/component docs to reflect conditional references and clarify the SQLite driver’s non-production role.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
test/sts2/Microsoft.SqlTools.Sts2.UnitTests/Architecture/DependencyMatrixTests.cs	Adds an architecture guard test verifying SQLite is opt-in at the Bootstrap csproj level.
test/sts2/Microsoft.SqlTools.Sts2.E2ETests/StdioE2ETests.cs	Adds a test asserting default subject outputs contain no SQLite assets; updates SQLite E2E test to spawn a SQLite-enabled subject.
test/sts2/Microsoft.SqlTools.Sts2.E2ETests/ServiceProcessClient.cs	Adds includeSqlite support to locate/spawn either default or isolated SQLite-enabled subject output.
test/sts2/Microsoft.SqlTools.Sts2.E2ETests/Microsoft.SqlTools.Sts2.E2ETests.csproj	Adds an MSBuild target to build an isolated SQLite-enabled ServiceLayer subject into separate bin/obj paths.
src/sts2/Microsoft.SqlTools.Sts2.Testing/GeneratedDocs.cs	Enhances generated component docs to include MSBuild Condition for conditional project references.
src/sts2/Microsoft.SqlTools.Sts2.Drivers.Sqlite/Microsoft.SqlTools.Sts2.Drivers.Sqlite.csproj	Clarifies non-production/test positioning in project description and comments about dependency propagation.
src/sts2/Microsoft.SqlTools.Sts2.Drivers.Sqlite/COMPONENT.md	Updates role description and documents opt-in entry into the ServiceLayer graph.
src/sts2/Microsoft.SqlTools.Sts2.Bootstrap/Sts2Bootstrap.cs	Wraps SQLite driver registration behind STS2_INCLUDE_SQLITE_DRIVER and centralizes driver construction.
src/sts2/Microsoft.SqlTools.Sts2.Bootstrap/Microsoft.SqlTools.Sts2.Bootstrap.csproj	Introduces IncludeSts2SqliteDriver defaulting to false, adds conditional define, and conditions the SQLite ProjectReference.
src/sts2/Microsoft.SqlTools.Sts2.Bootstrap/COMPONENT.md	Documents conditional dependency on Drivers.Sqlite and opt-in guidance.
docs/sts2/COMPONENTS.md	Updates generated output to include conditional project-reference conditions and updated SQLite role text.
docs/sts2/CLIENT.md	Documents that the sample uses the SQLite test driver and how to opt in for local builds.
Directory.Build.props	Adds isolated output/intermediate paths for the SQLite-enabled E2E subject to avoid contaminating default outputs.

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[Karl Burtram (kburtram)]

CI follow-up: I reproduced the NU1510 failure locally; it was deterministic, not transient. The E2E project's nested MSBuild calls inherited the outer TargetFramework=net10.0 global property from Cake, which forced transitive projects (including the normally net8.0 SqlCore project) to net10.0 and made their framework-provided PackageReferences appear redundant. Commit 8a2b6bb removes TargetFramework from those nested calls so each project keeps its declared target framework. Validation: the exact failing dotnet build now completes with 0 warnings/errors, the STS2 E2E suite passes 7/7, and Cake BuildTest succeeds end to end.

[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated no new comments.

Suppressed comments (3)

Previously missed (1) — in code that hasn't changed since the last review.

test/sts2/Microsoft.SqlTools.Sts2.UnitTests/Architecture/DependencyMatrixTests.cs:112

• Assert.Contains(..., includeProperty.Attribute("Condition")?.Value) will throw if the Condition attribute is missing (null) rather than producing a clear assertion failure. Capture and assert the attribute is present first so failures are easier to diagnose.

This issue also appears on line 120 of the same file.

            XElement includeProperty = Assert.Single(
                bootstrapProject.Descendants("IncludeSts2SqliteDriver"));
            Assert.Equal("false", includeProperty.Value);
            Assert.Contains("IncludeSts2SqliteDriver", includeProperty.Attribute("Condition")?.Value);

test/sts2/Microsoft.SqlTools.Sts2.E2ETests/StdioE2ETests.cs:63

• The file glob pattern "sqlite" is case-sensitive on some platforms (e.g., Linux). This test could miss SQLite-related assets such as "SQLitePCLRaw.*" and pass even when SQLite files are present. Prefer enumerating all files and doing a case-insensitive substring check.

        public void DefaultSubjectExcludesSqliteAssets()
        {
            string serviceDirectory = Path.GetDirectoryName(ServiceProcessClient.LocateServiceDll())!;
            Assert.Empty(Directory.EnumerateFiles(serviceDirectory, "*sqlite*", SearchOption.AllDirectories));

test/sts2/Microsoft.SqlTools.Sts2.UnitTests/Architecture/DependencyMatrixTests.cs:122

• Similarly, Assert.Contains(..., condition) will throw if the ProjectReference Condition attribute is missing. Asserting the attribute exists first provides a clearer test failure and avoids an unexpected exception path.

            string? condition = sqliteReference.Attribute("Condition")?.Value;
            Assert.Contains("IncludeSts2SqliteDriver", condition);
            Assert.Contains("true", condition);