add some macro tests

spec/ysh-macros.test.sh

@@ -0,0 +1,58 @@
+## our_shell: ysh
+## oils_failures_allowed: 10000
+
+#### Unless syntax sugar
+macro unless (; cond ;; block) {
+  return (quote {
+    if (not (unquote cond)) {
+      (unquote block)
+    }
+  })
+}
+
+unless (1 > 2) {
+  echo rocks
+}
+## status: 0
+## STDOUT:
+rocks
+## END
+
+#### withMutex syntax sugar
+proc mutexCreate() {
+  var mutexPath = $(mktemp)
+}
+macro withMutex (; ...mutexesWithBlk) {
+  if (len(mutexesWithBlk) == 1) {
+    return (mutexesWithBlk[0])
+  } else {
+    var mutexesRest = mutexesWithBlk[1:]
+    var mutexCurrent = mutexesWithBlk[0]
+    return (
+      quote {
+        {
+          if flock $fd {
+            unquote (withMutex (...mutexesRest))
+          } else {
+            echo "Failed to grab the lock `$mutexCurrent`"
+            exit 1
+          }
+        } {fd}<$mutexCurrent
+      }
+    )
+  }
+}
+
+var lock1 = mutexCreate
+var lock2 = mutexCreate
+var lock3 = mutexCreate
+withMutex (lock1, lock2, lock3) {
+  echo rocks
+}
+## status: 0
+## STDOUT:
+rocks
+## END
+
+
+