Refactoring

src/functions/parse.ts

@@ -0,0 +1,26 @@
+import { Transform } from "stream";
+import { StringDecoder } from "string_decoder";
+import { SerializationFormats } from "./baseDefinitions";
+/**
+ * Return a ReadWrite stream that parses the streamed chunks as JSON. Each streamed chunk
+ * must be a fully defined JSON string.
+ * @param format Format of serialized data, only utf8 supported.
+ */
+export function parse(
+    format: SerializationFormats = SerializationFormats.utf8,
+): Transform {
+    const decoder = new StringDecoder(format);
+    return new Transform({
+        readableObjectMode: true,
+        writableObjectMode: true,
+        async transform(chunk: Buffer, encoding, callback) {
+            try {
+                const asString = decoder.write(chunk);
+                // Using await causes parsing errors to be emitted
+                callback(undefined, await JSON.parse(asString));
+            } catch (err) {
+                callback(err);
+            }
+        },
+    });
+}