Added migrations module for target format converting.

src/datasource-zabbix/migrations.js

@@ -0,0 +1,53 @@
+/**
+ * Query format migration.
+ * This module can detect query format version and make migration.
+ */
+
+import * as utils from './utils';
+
+export function isGrafana2target(target) {
+  if ((target.hostFilter || target.itemFilter || target.downsampleFunction ||  target.host.host) &&
+      (!target.functions && !target.host.filter)) {
+    return true;
+  } else {
+    return false;
+  }
+}
+
+export function migrateFrom2To3version(target) {
+  utils.isRegex(target.host.name);
+  var newTarget = {
+    group: {
+      filter: target.group.name === "*" ? "/.*/" : target.group.name,
+      isRegex: target.group.name === "*"
+    },
+    host: {
+      filter: target.host.name === "*" ? convertToRegex(target.hostFilter) : target.host.name,
+      isRegex: target.host.name === "*"
+    },
+    application: {
+      filter: target.application.name === "*" ? "" : target.application.name,
+      isRegex: target.application.name === "*"
+    },
+    item: {
+      filter: target.item.name === "All" ? convertToRegex(target.itemFilter) : target.item.name,
+      isRegex: target.item.name === "All"
+    },
+    functions: [],
+    mode: target.mode,
+    hide: target.hide,
+  };
+  return newTarget;
+}
+
+export function migrate(target) {
+  if (isGrafana2target(target)) {
+    return migrateFrom2To3version(target);
+  } else {
+    return target;
+  }
+}
+
+function convertToRegex(str) {
+  return '/' + str + '/';
+}