custom

p := NewJavascriptProcessor(log.Nop())

exampleutil.RunExample(p, exampleutil.Example{
	Summary: "Modify a record's metadata and payload using JavaScript",
	Description: "In this example we use the `custom.javascript` processor to add a metadata key " +
		"to the input record. It also prepends \"hello, \" to `.Payload.After`.",
	Config: config.Config{
		"script": `function process(rec) {
  rec.Metadata["processed"] = "true";
  let existing = String.fromCharCode.apply(String, rec.Payload.After);
  rec.Payload.After = RawData("hello, " + existing);
  return rec;
}`,
	},
	Have: opencdc.Record{
		Metadata: map[string]string{
			"existing-key": "existing-value",
		},
		Payload: opencdc.Change{
			After: opencdc.RawData("world"),
		},
	},
	Want: sdk.SingleRecord{
		Metadata: map[string]string{
			"existing-key": "existing-value",
			"processed":    "true",
		},
		Payload: opencdc.Change{
			After: opencdc.RawData("hello, world"),
		},
	},
})

Output:

processor transformed record:
--- before
+++ after
@@ -1,12 +1,13 @@
 {
   "position": null,
   "operation": "Operation(0)",
   "metadata": {
-    "existing-key": "existing-value"
+    "existing-key": "existing-value",
+    "processed": "true"
   },
   "key": null,
   "payload": {
     "before": null,
-    "after": "world"
+    "after": "hello, world"
   }
 }