From 8c10ceabf861158cbb956bf5c176eaf6c58549fa Mon Sep 17 00:00:00 2001
From: Russell Martin <russell@rjm.li>
Date: Sat, 9 Mar 2024 11:47:38 -0500
Subject: [PATCH] Only produce coverage with tox when necessary

---
 .github/workflows/ci.yml |  2 +-
 changes/1690.misc.rst    |  1 +
 tox.ini                  | 27 ++++++++++++++-------------
 3 files changed, 16 insertions(+), 14 deletions(-)
 create mode 100644 changes/1690.misc.rst

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c99859160..82109fbbe 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -95,7 +95,7 @@ jobs:
         RUNNER_OS=$(cut -d- -f1 <<< ${{ matrix.platform }})
         RUNNER_VERSION=$(cut -d- -f2 <<< ${{ matrix.platform }})
         COVERAGE_FILE=".coverage.${RUNNER_OS}.${RUNNER_VERSION}.${{ matrix.python-version }}" \
-          tox -e py --installpkg dist/briefcase-*.whl
+          tox -e py-cov --installpkg dist/briefcase-*.whl
 
     - name: Store Coverage Data
       if: always() && contains('success,failure', steps.test.outcome)
diff --git a/changes/1690.misc.rst b/changes/1690.misc.rst
new file mode 100644
index 000000000..50c54d970
--- /dev/null
+++ b/changes/1690.misc.rst
@@ -0,0 +1 @@
+The tox environments for running the test suite were updated to only produce coverage databases when necessary.
diff --git a/tox.ini b/tox.ini
index 6daaafbb8..665f0d030 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,18 +16,18 @@ extend-ignore =
     E203,
 
 [tox]
-envlist = towncrier-check,docs-lint,pre-commit,py{38,39,310,311,312,313},coverage
+envlist = towncrier-check,docs-lint,pre-commit,py{38,39,310,311,312,313}-cov,coverage
 labels =
-    test = py{38,39,310,311,312,313},coverage
-    test38 = py38,coverage38
-    test39 = py39,coverage39
-    test310 = py310,coverage310
-    test311 = py311,coverage311
-    test312 = py312,coverage312
-    test313 = py313,coverage313
+    test = py{38,39,310,311,312,313}-cov,coverage
+    test38 = py38-cov,coverage38
+    test39 = py39-cov,coverage39
+    test310 = py310-cov,coverage310
+    test311 = py311-cov,coverage311
+    test312 = py312-cov,coverage312
+    test313 = py313-cov,coverage313
     test-fast = py{38,39,310,311,312,313}-fast
-    test-platform = py{38,39,310,311,312,313},coverage-platform
-    ci = towncrier-check,docs-lint,pre-commit,py{38,39,310,311,312,313},coverage-platform
+    test-platform = py{38,39,310,311,312,313}-cov,coverage-platform
+    ci = towncrier-check,docs-lint,pre-commit,py{38,39,310,311,312,313}-cov,coverage-platform
 skip_missing_interpreters = True
 
 [testenv:pre-commit]
@@ -39,7 +39,7 @@ deps =
 commands_pre = python -m install_requirement pre-commit --extra dev --project-root "{tox_root}"
 commands = pre-commit run --all-files --show-diff-on-failure --color=always
 
-[testenv:py{,38,39,310,311,312,313}{,-fast}]
+[testenv:py{,38,39,310,311,312,313}{,-fast,-cov}]
 package = wheel
 wheel_build_env = .pkg
 depends: pre-commit
@@ -49,11 +49,12 @@ passenv = LOCALAPPDATA
 setenv = COVERAGE_FILE = {env:COVERAGE_FILE:.coverage}
 extras = dev
 commands =
-    !fast : python -X warn_default_encoding -m coverage run -m pytest {posargs:-vv --color yes}
+    !fast-!cov : python -X warn_default_encoding -m pytest {posargs:-vv --color yes}
+    cov  : python -X warn_default_encoding -m coverage run -m pytest {posargs:-vv --color yes}
     fast : python -m pytest {posargs:-vv --color yes -n auto}
 
 [testenv:coverage{,38,39,310,311,312,313}{,-ci}{,-platform,-platform-linux,-platform-macos,-platform-windows,-project}{,-keep}{,-html}]
-depends = py{,38,39,310,311,312,313}
+depends = pre-commit,py{,38,39,310,311,312,313}{,-cov}
 skip_install = True
 # by default, coverage should run on oldest supported Python for testing platform coverage.
 # however, coverage for a particular Python version should match the version used for pytest.