stream

ngron.mjs

@@ -28,7 +28,7 @@ const iter = (obj, key, lines) => {
 export const gronify = (obj) => {
   const lines = []
 
-  iter(obj, ["json"], lines)
+  iter(obj, "json", lines)
 
   return lines.join('\n');
 

ngronstream.mjs

@@ -0,0 +1,39 @@
+import { Readable } from "node:stream";
+
+const objType = (obj) => {
+  if (obj === null) {
+    return 'null'
+  }
+  if (Array.isArray(obj)) {
+    return 'array'
+  }
+
+  return typeof obj
+}
+
+function* gronGenerator(obj, root = `json`) {
+  switch (objType(obj)) {
+    case 'object':
+      yield `${root}={};\n`;
+      for (const key in obj) {
+        yield* gronGenerator(obj[key], `${root}.${key}`);
+      }
+      break;
+    case 'array':
+      yield `${root}=[];\n`;
+      for (let i = 0; i < obj.length; i++) {
+        yield* gronGenerator(obj[i], `${root}[${i}]`);
+      }
+      break;
+
+    default:
+      yield `${root}=${JSON.stringify(obj)};\n`;
+
+  }
+}
+
+export const gronReadStream = (obj) => {
+
+  return Readable.from(gronGenerator(obj));
+
+}

ngronstream.test.mjs

@@ -0,0 +1,91 @@
+import test from "node:test"
+import assert from "node:assert"
+import { gronReadStream } from "./ngronstream.mjs";
+
+const asString = async (stream) => {
+  const chunks = [];
+  for await (const chunk of stream) {
+    chunks.push(Buffer.from(chunk))
+  }
+  return Buffer.concat(chunks).toString('utf8');
+}
+
+test("number", async () => {
+  const rs = gronReadStream(3);
+  const result = await asString(rs);
+
+  assert.strictEqual(result, `json=3;\n`)
+});
+
+test("string", async () => {
+  const rs = gronReadStream("hello")
+  const result = await asString(rs);
+
+  assert.strictEqual(result, `json="hello";\n`)
+});
+
+test("null", async () => {
+  const rs = gronReadStream(null)
+  const result = await asString(rs);
+
+  assert.strictEqual(result, `json=null;\n`)
+});
+
+test("empty obj", async () => {
+  const rs = gronReadStream({})
+  const result = await asString(rs);
+
+  assert.strictEqual(result, `json={};\n`)
+});
+
+test("empty array", async () => {
+  const rs = gronReadStream([])
+  const result = await asString(rs);
+
+  assert.strictEqual(result, `json=[];\n`)
+});
+
+test("nested obj", async () => {
+  const rs = gronReadStream({ one: 1 })
+  const result = await asString(rs);
+
+  assert.strictEqual(result, `
+json={};
+json.one=1;
+`.trimStart())
+});
+
+test("nested array", async () => {
+  const rs = gronReadStream(["hello", "world"])
+  const result = await asString(rs);
+
+  assert.strictEqual(result, `
+json=[];
+json[0]="hello";
+json[1]="world";
+`.trimStart())
+});
+
+test("complex", async () => {
+  const rs = gronReadStream([
+    { name: "Alice", startYear: 2001 },
+    { name: "Ralph", startYear: 2010 },
+    { name: "Jesse", startYear: 2007, tired: true },
+  ]);
+  const result = await asString(rs);
+
+  assert.strictEqual(result, `
+json=[];
+json[0]={};
+json[0].name="Alice";
+json[0].startYear=2001;
+json[1]={};
+json[1].name="Ralph";
+json[1].startYear=2010;
+json[2]={};
+json[2].name="Jesse";
+json[2].startYear=2007;
+json[2].tired=true;
+`.trimStart());
+
+});