Native VS Code Language Model Tools for Test Context (tctx) — incremental Python (pytest + ruff) and Rust (cargo test) AST dependency analysis, speculative background execution, and sub-millisecond cached test results for GitHub Copilot.
Publisher: dotnetpower (dotnetpower.test-context-native).
Across 8 independent daemon sessions (320 paired observations) on AKS Store Demo (src/ai-service):
Task
TCTX off (pytest)
TCTX on
Speedup [95% CI]
Warm suite (warm_suite)
1000.90 ms
0.56 ms (median 0.53 ms)
1796.00× [1710.88, 1867.12]
Post-edit background pre-run (bg_speculative)
994.27 ms
0.81 ms (median 0.51 ms)
1230.61× [817.21, 1915.37]
Reverted edit Merkle hit (merkle_revert)
988.26 ms
0.60 ms (median 0.55 ms)
1643.59× [1413.96, 1850.33]
Immediate 0ms-delay leaf edit (leaf_delta)
981.56 ms
78.14 ms (median 74.92 ms)
12.56× [12.00, 13.18]
Impact query + Ruff pre-check (affected_graph)
960.91 ms
0.47 ms (median 0.45 ms)
2049.69× [1957.13, 2155.51]
Fixed mixed suite (all, 320 pairs)
985.18 ms
16.11 ms (median 0.53 ms)
61.13× [57.39, 64.72]
Install
git clone https://github.com/dotnetpower/test-context.git && cd test-context
./scripts/install.sh
code --install-extension dotnetpower.test-context-native
For Windows Agents windows backed by WSL, run ./scripts/install-vscode-extension.sh from WSL to configure the wsl.exe --exec tctx native-bridge transport automatically.
Contributed Language Model Tools
#tctxNativeRun (test-context-native_testRun): Run pytest and cargo test incrementally with instant cache hits for tests already verified in the background, plus pre-flight Ruff diagnostics and optional ruff_fix: true auto-remediation.
#tctxNativeAffected (test-context-native_testAffected): Inspect which Python/Rust test files are affected by modified source files or git diff, along with their live background cache state and pre-checked Ruff errors.
#tctxNativeGraph (test-context-native_testGraph): Query direct imports, reverse importers, transitive dependencies, conftest.py / tests/common chains, referenced env vars, and Merkle dep_hash for any Python or Rust file.
#tctxNativeStatus (test-context-native_testStatus): View daemon health, indexed Python/Rust counts, cached test counts, Ruff diagnostic counts, background worker queue, and total time saved.
#tctxNativeSync (test-context-native_testSync): Force AST graph synchronization and schedule background test execution.
#tctxNativeInvalidate (test-context-native_testInvalidate): Invalidate cached test results for specific files or the entire workspace.
#tctxNativeWorkspaces (test-context-native_testWorkspaces): List registered tctx workspaces.
