import { parseNdjsonChunk } from "../../src/lib/ndjson";
describe("parseNdjsonChunk", () => {
test("parses JSON lines and returns parsed msg", () => {
const { buffer, records } = parseNdjsonChunk("", '{"a":1}\n');
expect(buffer).toBe("");
expect(records).toHaveLength(1);
expect(records[0].line).toBe('{"a":1}');
expect(records[0].msg).toEqual({ a: 1 });
});
test("returns msg undefined for non-JSON line", () => {
const { buffer, records } = parseNdjsonChunk("", "hello\n");
expect(buffer).toBe("");
expect(records).toHaveLength(1);
expect(records[0].line).toBe("hello");
expect(records[0].msg).toBeUndefined();
});
test("handles blank lines (msg should be undefined)", () => {
const { buffer, records } = parseNdjsonChunk("", "\n");
expect(buffer).toBe("");
expect(records).toHaveLength(1);
expect(records[0].line).toBe("");
expect(records[0].msg).toBeUndefined();
});
test("keeps incomplete tail in buffer when chunk doesn't end with newline", () => {
const { buffer, records } = parseNdjsonChunk("", '{"a":1}\n{"b":2}');
// only the first complete line should be parsed
expect(records).toHaveLength(1);
expect(records[0].line).toBe('{"a":1}');
expect(records[0].msg).toEqual({ a: 1 });
// the second JSON is incomplete (no trailing newline) and should be preserved in buffer
expect(buffer).toBe('{"b":2}');
});
test("combines existing buffer with chunk to form a complete JSON line", () => {
// simulate a JSON object split across two chunks
const initial = '{"a":';
const { buffer, records } = parseNdjsonChunk(initial, "1}\n");
expect(records).toHaveLength(1);
expect(records[0].line).toBe('{"a":1}');
expect(records[0].msg).toEqual({ a: 1 });
expect(buffer).toBe("");
});
test("mixed lines: JSON, non-JSON, blank, and incomplete tail", () => {
const chunk = '{"x":10}\nnot-json\n\n{"y":20}\npartial-start';
const { buffer, records } = parseNdjsonChunk("", chunk);
// records should contain 4 entries (last 'partial-start' is kept in buffer)
expect(records).toHaveLength(4);
expect(records[0].msg).toEqual({ x: 10 });
expect(records[1].msg).toBeUndefined();
expect(records[1].line).toBe("not-json");
expect(records[2].line).toBe("");
expect(records[2].msg).toBeUndefined();
expect(records[3].msg).toEqual({ y: 20 });
expect(buffer).toBe("partial-start");
});
});
