ci: add a check for tabs

Surprisingly, none of the standard tools complain about tabs in the
code, at least in some locations. I expected that python3 would always
complain, or at least tabnanny, or pyflakes… Let's roll a simple custom
check.

Use '-P' to request perl-compatible regular expressions even the user
has a different default configures so that '\t' works as expected.

diff --git a/.github/workflows/ci-unit-test.yml b/.github/workflows/ci-unit-test.yml
index 798d3e600d8b703acc72e302e51165cec4e43dc8..5eaa72713f8972cecf35df5dbf541869b081d584 100644 (file)
--- a/.github/workflows/ci-unit-test.yml
+++ b/.github/workflows/ci-unit-test.yml
@@ -25,6 +25,9 @@ jobs:
     - name: Run pyflakes
       run: python3 -m pyflakes mkosi/ tests/
 
+    - name: Check that tabs are not used in code
+      run: sh -c '! git grep -P "\\t" "*.py"'
+
     - name: Type Checking (mypy)
       run: python3 -m mypy --python-version 3.7 mkosi