Merge pull request #1515 from rbenv/help-usage

help: have `--usage` always print a usage line

libexec/rbenv-help

@@ -144,7 +144,11 @@ print_usage() {
   local command="$1"
   local summary usage help
   eval "$(documentation_for "$command")"
-  [ -z "$usage" ] || echo "$usage"
+  if [ -n "$usage" ]; then
+    echo "$usage"
+  else
+    echo "Usage: rbenv ${command}"
+  fi
 }
 
 unset usage

test/help.bats

@@ -71,6 +71,18 @@ SH
   assert_success "Usage: rbenv hello <world>"
 }
 
+@test "empty usage section" {
+  mkdir -p "${RBENV_TEST_DIR}/bin"
+  cat > "${RBENV_TEST_DIR}/bin/rbenv-hello" <<SH
+#!shebang
+# Summary: Says "hello" to you, from rbenv
+echo hello
+SH
+
+  run rbenv-help --usage hello
+  assert_success "Usage: rbenv hello"
+}
+
 @test "multiline usage section" {
   mkdir -p "${RBENV_TEST_DIR}/bin"
   cat > "${RBENV_TEST_DIR}/bin/rbenv-hello" <<SH