feat: behavior builders

packages/behavior/builders.js

@@ -0,0 +1,41 @@
+export function buildTraversal(path, value) {
+  const traversal = {
+    type: 'traversal',
+    steps: path.map((key) => {
+      return {
+        type: 'key',
+        key: key,
+      };
+    }),
+  };
+  if ('undefined' !== typeof value) {
+    if ('object' === typeof value && 'traversal' === value.type) {
+      traversal.value = value;
+    }
+    else {
+      traversal.value = {
+        type: 'literal',
+        value,
+      };
+    }
+  }
+  return traversal;
+}
+
+export const buildInvoke = (path, args) => {
+  const traversal = buildTraversal(path);
+  traversal.steps.push({
+    type: 'invoke',
+    args: args.map((arg) => {
+      if ('object' === typeof arg && 'traversal' === arg.type) {
+        return arg;
+      }
+      return {
+        type: 'literal',
+        value: arg,
+      };
+    }),
+  });
+  return traversal;
+}
+

packages/behavior/index.js

@@ -8,3 +8,4 @@ export {
   fromJSON as behaviorItemFromJSON,
   register as registerBehaviorItem
 } from './item/registry';
+export {buildInvoke, buildTraversal} from './builders';