Split discovery of alternates test data into a testable function

test/test_unit_set_local_alt_values.py

@@ -0,0 +1,62 @@
+"""Unit tests: set_local_alt_values"""
+import pytest
+import utils
+
+
+@pytest.mark.parametrize(
+    'override', [
+        False,
+        'class',
+        'os',
+        'hostname',
+        'user',
+        ],
+    ids=[
+        'no-override',
+        'override-class',
+        'override-os',
+        'override-hostname',
+        'override-user',
+        ]
+    )
+@pytest.mark.usefixtures('ds1_copy')
+def test_set_local_alt_values(
+        runner, yadm, paths, tst_sys, tst_host, tst_user, override):
+    """Use issue_legacy_path_warning"""
+    script = f"""
+        YADM_TEST=1 source {yadm} &&
+        set_operating_system &&
+        YADM_DIR={paths.yadm} configure_paths &&
+        set_local_alt_values
+        echo "class='$local_class'"
+        echo "os='$local_system'"
+        echo "host='$local_host'"
+        echo "user='$local_user'"
+    """
+
+    if override:
+        utils.set_local(paths, override, 'override')
+
+    run = runner(command=['bash'], inp=script)
+    assert run.success
+    assert run.err == ''
+
+    if override == 'class':
+        assert "class='override'" in run.out
+    else:
+        assert "class=''" in run.out
+
+    if override == 'os':
+        assert "os='override'" in run.out
+    else:
+        assert f"os='{tst_sys}'" in run.out
+
+    if override == 'hostname':
+        assert f"host='override'" in run.out
+    else:
+        assert f"host='{tst_host}'" in run.out
+
+    if override == 'user':
+        assert f"user='override'" in run.out
+    else:
+        assert f"user='{tst_user}'" in run.out

yadm

@@ -135,34 +135,41 @@ function alt() {
   require_repo
   parse_encrypt
 
+  # gather values for processing alternates
   local local_class
+  local local_system
+  local local_host
+  local local_user
+  set_local_alt_values
+
+  if [ "$YADM_COMPATIBILITY" = "1" ]; then
+    alt_past
+  else
+    alt_future
+  fi
+
+}
+
+function set_local_alt_values() {
+
   local_class="$(config local.class)"
 
-  local local_system
   local_system="$(config local.os)"
   if [ -z "$local_system" ] ; then
     local_system="$OPERATING_SYSTEM"
   fi
 
-  local local_host
   local_host="$(config local.hostname)"
   if [ -z "$local_host" ] ; then
     local_host=$(hostname)
     local_host=${local_host%%.*} # trim any domain from hostname
   fi
 
-  local local_user
   local_user="$(config local.user)"
   if [ -z "$local_user" ] ; then
     local_user=$(id -u -n)
   fi
 
-  if [ "$YADM_COMPATIBILITY" = "1" ]; then
-    alt_past
-  else
-    alt_future
-  fi
-
 }
 
 function alt_future() {