Change: ./check to run yarn only if yarnutils is installed

On the version of cmdtest (in which yarn is) there is no yarnutils.
Since yarn is on its way to the dung heap of my obsolete projects,
there's no point in doing a backport of cmdtest. Better put that
energy into improving Subplot.

1 files changed, 10 insertions, 11 deletions

diff --git a/check b/check
index e9cdfac..43f671a 100755
--- a/check
+++ b/check
@@ -14,19 +14,19 @@ then
     echo
 fi
 
-if false; then
 echo Running yarn tests ========================================
-yarn \
-    --shell=python3 \
-    --shell-arg '' \
-    --shell-library yarns/lib.py \
-    --env "PYTHONPATH=$(pwd)/yarns" \
-    --cd-datadir \
-    yarns/*.yarn "$@"
-echo
+if python3 -c 'import yarnutils' 2>/dev/null
+then
+    yarn \
+        --shell=python3 \
+        --shell-arg '' \
+        --shell-library yarns/lib.py \
+        --env "PYTHONPATH=$(pwd)/yarns" \
+        --cd-datadir \
+        yarns/*.yarn "$@"
+    echo
 fi
 
-if false; then
 echo Formatting docs ========================================
 ./format.sh
 
@@ -54,4 +54,3 @@ if ! diff -u <(steps) <(steps | sort)
 then
     panic "Steps are not in sorted order"
 fi
-fi