Fix (#27)

Author: uaArsen

CHANGELOG.md

@@ -1,3 +1,11 @@
+## 1.1.2 (March 24, 2020)
+
+### Bug fixes
+
+* Fix subsequent calls to Jsonata Transform error
+## Note
+* `JsontaTransform.jsonataTransform` now will not change body of input message
+
 ## 1.1.1 (March 24, 2020)
 
 ### General Changes

lib/jsonataTransform/jsonataTransform.ts

@@ -8,17 +8,18 @@ const PASSTHROUGH_BODY_PROPERTY = 'elasticio';
  * @param msg incoming message object that contains ``body`` with payload
  * @param cfg configuration that is account information and configuration field values
  * @param context this of action or trigger, optional
+
  */
 export function jsonataTransform(msg, cfg, context) {
   const expression = cfg.expression;
   const compiledExpression = jsonata(expression);
   if (context && context.getFlowVariables) {
     compiledExpression.assign('getFlowVariables', () => context.getFlowVariables());
   }
-  handlePassthrough(msg);
-  const passthrough = msg.body[PASSTHROUGH_BODY_PROPERTY];
+  const handledMessage = handlePassthrough(msg);
+  const passthrough = handledMessage.body[PASSTHROUGH_BODY_PROPERTY];
   compiledExpression.assign('getPassthrough', () => passthrough);
-  return compiledExpression.evaluate(msg.body);
+  return compiledExpression.evaluate(handledMessage.body);
 }
 
 function handlePassthrough(message) {
@@ -27,9 +28,10 @@ function handlePassthrough(message) {
       throw new Error(`${PASSTHROUGH_BODY_PROPERTY} property is reserved \
             if you are using passthrough functionality`);
     }
-
-    message.body.elasticio = {};
-    Object.assign(message.body.elasticio, message.passthrough);
+    const result = JSON.parse(JSON.stringify(message)); // Otherwise subsequent calls to Jsonata transform with same message would fail
+    result.body.elasticio = {};
+    Object.assign(result.body.elasticio, result.passthrough);
+    return result;
   }
   return message;
 }

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "@elastic.io/component-commons-library",
-  "version": "1.1.1",
+  "version": "1.1.2",
   "description": "Library for most common component development cases",
   "author": {
     "name": "elastic.io GmbH",

package.json

@@ -69,7 +69,31 @@ describe('Transformation test', () => {
     };
     const result = JsonataTransform.jsonataTransform(msg, {
       expression: '$getFlowVariables()',
-    },                                               { getFlowVariables: () => flowVariables});
+    },                                               { getFlowVariables: () => flowVariables });
     expect(result).to.deep.equal(flowVariables);
   });
+  it('should handle 2 expressions on same message if dontThrowError=true', () => {
+    const msg = eioUtils.newMessageWithBody({
+      first: 'Renat',
+      last: 'Zubairov',
+    });
+    msg.passthrough = {
+      ps: 'psworks',
+    };
+    const first = JsonataTransform.jsonataTransform(msg, {
+      expression: '$getPassthrough()',
+    },                                              null);
+    msg.passthrough = { test: 'test' };
+    const second = JsonataTransform.jsonataTransform(msg, {
+      expression: '$getPassthrough()',
+    },                                               null);
+
+    expect(first).to.deep.equal({
+      ps: 'psworks',
+    });
+    expect(second).to.deep.equal({
+      test: 'test',
+    });
+    expect(msg.body.elasticio).to.be.undefined;
+  });
 });