feat: AI schedule JSON parser

src/__tests__/ai/parser.test.ts

@@ -0,0 +1,28 @@
+import { parseScheduleJson } from '../../ai/parser';
+
+describe('parseScheduleJson', () => {
+  it('parses a valid JSON array', () => {
+    const input = JSON.stringify([
+      { date: '2026-05-22', planned_min: 60, rationale: 'Continue level' },
+      { date: '2026-05-24', planned_min: 75, rationale: 'Step up' },
+    ]);
+    const result = parseScheduleJson(input);
+    expect(result).toHaveLength(2);
+    expect(result[0]).toEqual({ date: '2026-05-22', planned_min: 60, rationale: 'Continue level' });
+  });
+
+  it('parses JSON wrapped in a markdown code block', () => {
+    const input = '```json\n[{"date":"2026-05-22","planned_min":60,"rationale":"test"}]\n```';
+    const result = parseScheduleJson(input);
+    expect(result).toHaveLength(1);
+    expect(result[0]!.date).toBe('2026-05-22');
+  });
+
+  it('throws on invalid JSON', () => {
+    expect(() => parseScheduleJson('not json')).toThrow();
+  });
+
+  it('throws if entries are missing required fields', () => {
+    expect(() => parseScheduleJson(JSON.stringify([{ date: '2026-05-22' }]))).toThrow();
+  });
+});

src/ai/parser.ts

@@ -0,0 +1,21 @@
+export interface ScheduleProposal {
+  date: string;
+  planned_min: number;
+  rationale: string;
+}
+
+export function parseScheduleJson(raw: string): ScheduleProposal[] {
+  const cleaned = raw.replace(/^```(?:json)?\n?/, '').replace(/\n?```$/, '').trim();
+  const parsed = JSON.parse(cleaned);
+
+  if (!Array.isArray(parsed)) throw new Error('Expected a JSON array');
+
+  return parsed.map((entry: unknown, i: number) => {
+    if (typeof entry !== 'object' || entry === null) throw new Error(`Entry ${i} is not an object`);
+    const e = entry as Record<string, unknown>;
+    if (typeof e['date'] !== 'string') throw new Error(`Entry ${i} missing "date"`);
+    if (typeof e['planned_min'] !== 'number') throw new Error(`Entry ${i} missing "planned_min"`);
+    if (typeof e['rationale'] !== 'string') throw new Error(`Entry ${i} missing "rationale"`);
+    return { date: e['date'], planned_min: e['planned_min'], rationale: e['rationale'] };
+  });
+}