feat: add Drone CI pipelines, Jest unit tests, and Prettier check

Add Drone CI with server build/test and format check pipelines.
Add unit tests for password utils and recurrenceExpander.
Add check_format script, fix Jest config to ignore dist/,
remove dead CaldavService.test.ts, apply Prettier formatting.

.drone.yml

@@ -0,0 +1,31 @@
+---
+
+kind: pipeline
+name: server_build_and_test
+
+steps:
+  - name: build_server
+    image: node
+    commands:
+      - npm ci -w @calchat/shared
+      - npm ci -w @calchat/server
+      - npm run build -w @calchat/server
+
+  - name: jest_server
+    image: node
+    commands:
+      - npm run test -w @calchat/server
+
+---
+
+kind: pipeline
+name: check_for_formatting
+
+steps:
+  - name: format_check
+    image: node
+    commands:
+      - npm ci
+      - npm run check_format
+
+---

CLAUDE.md

@@ -14,6 +14,7 @@ This is a fullstack TypeScript monorepo with npm workspaces.
 ```bash
 npm install          # Install all dependencies for all workspaces
 npm run format       # Format all TypeScript files with Prettier
+npm run check_format # Check formatting without modifying files (used in CI)
 ```
 
 ### Client (apps/client) - Expo React Native app
@@ -36,6 +37,7 @@ npm run build -w @calchat/shared        # Compile shared types to dist/
 npm run dev -w @calchat/server          # Build shared + start dev server with hot reload (tsx watch)
 npm run build -w @calchat/server        # Build shared + compile TypeScript
 npm run start -w @calchat/server        # Run compiled server (port 3000)
+npm run test -w @calchat/server         # Run Jest unit tests
 ```
 
 ## Technology Stack
@@ -58,7 +60,9 @@ npm run start -w @calchat/server        # Run compiled server (port 3000)
 | | react-native-logs | Client-side logging |
 | | tsdav | CalDAV client library |
 | | ical.js | iCalendar parsing/generation |
+| Testing | Jest / ts-jest | Server unit tests |
 | Deployment | Docker | Server containerization (multi-stage build) |
+| | Drone CI | CI/CD pipelines (build, test, format check) |
 | Planned | iCalendar | Event export/import |
 
 ## Architecture
@@ -694,6 +698,21 @@ This uses the `preview` profile from `eas.json` which builds an APK with:
 - Package name: `com.gilmour109.calchat`
 - EAS Project ID: `b722dde6-7d89-48ff-9095-e007e7c7da87`
 
+## CI/CD (Drone)
+
+The project uses Drone CI (`.drone.yml`) with two pipelines:
+
+1. **`server_build_and_test`**: Builds the server (`npm ci` + `npm run build`) and runs Jest tests (`npm run test`)
+2. **`check_for_formatting`**: Checks Prettier formatting across all workspaces (`npm run check_format`)
+
+## Testing
+
+Server uses Jest with ts-jest for unit testing. Config in `apps/server/jest.config.js` ignores `/node_modules/` and `/dist/`.
+
+**Existing tests:**
+- `src/utils/password.test.ts` - Tests for bcrypt hash() and compare()
+- `src/utils/recurrenceExpander.test.ts` - Tests for expandRecurringEvents() (non-recurring, weekly/daily/UNTIL recurrence, EXDATE filtering, RRULE: prefix stripping, invalid RRULE fallback, multi-day events, sorting)
+
 ## Documentation
 
 Detailed architecture diagrams are in `docs/`:

apps/client/src/app/(tabs)/calendar.tsx

@@ -623,7 +623,7 @@ const CalendarToolbar = ({ loadEvents }: CalendarToolbarProps) => {
     elevation: 4,
   };
 
-  const className = "flex flex-row items-center gap-2 px-3 py-1 rounded-lg"
+  const className = "flex flex-row items-center gap-2 px-3 py-1 rounded-lg";
 
   return (
     <View

apps/client/src/app/(tabs)/settings.tsx

@@ -45,7 +45,9 @@ const CaldavTextInput = ({
   const { theme } = useThemeStore();
   return (
     <View className="flex flex-row items-center py-1">
-      <Text className="ml-4 w-24" style={{ color: theme.textPrimary }}>{title}:</Text>
+      <Text className="ml-4 w-24" style={{ color: theme.textPrimary }}>
+        {title}:
+      </Text>
       <CustomTextInput
         className="flex-1 mr-4 px-3 py-2"
         text={value}
@@ -111,7 +113,13 @@ const CaldavSettings = () => {
   );
 
   const saveConfig = async () => {
-    showFeedback(setSaveFeedback, saveTimer, "Speichere Konfiguration...", false, true);
+    showFeedback(
+      setSaveFeedback,
+      saveTimer,
+      "Speichere Konfiguration...",
+      false,
+      true,
+    );
     try {
       const saved = await CaldavConfigService.saveConfig(
         serverUrl,
@@ -119,9 +127,19 @@ const CaldavSettings = () => {
         password,
       );
       setConfig(saved);
-      showFeedback(setSaveFeedback, saveTimer, "Konfiguration wurde gespeichert", false);
+      showFeedback(
+        setSaveFeedback,
+        saveTimer,
+        "Konfiguration wurde gespeichert",
+        false,
+      );
     } catch {
-      showFeedback(setSaveFeedback, saveTimer, "Fehler beim Speichern der Konfiguration", true);
+      showFeedback(
+        setSaveFeedback,
+        saveTimer,
+        "Fehler beim Speichern der Konfiguration",
+        true,
+      );
     }
   };
 
@@ -129,9 +147,19 @@ const CaldavSettings = () => {
     showFeedback(setSyncFeedback, syncTimer, "Synchronisiere...", false, true);
     try {
       await CaldavConfigService.sync();
-      showFeedback(setSyncFeedback, syncTimer, "Synchronisierung erfolgreich", false);
+      showFeedback(
+        setSyncFeedback,
+        syncTimer,
+        "Synchronisierung erfolgreich",
+        false,
+      );
     } catch {
-      showFeedback(setSyncFeedback, syncTimer, "Fehler beim Synchronisieren", true);
+      showFeedback(
+        setSyncFeedback,
+        syncTimer,
+        "Fehler beim Synchronisieren",
+        true,
+      );
     }
   };
 

apps/server/jest.config.js

@@ -1,4 +1,5 @@
 module.exports = {
   preset: "ts-jest",
   testEnvironment: "node",
+  testPathIgnorePatterns: ["/node_modules/", "/dist/"],
 };

apps/server/src/controllers/AuthController.ts

@@ -21,5 +21,4 @@ export class AuthController {
       res.status(400).json({ error: (error as Error).message });
     }
   }
-
 }

apps/server/src/controllers/CaldavController.ts

@@ -15,7 +15,10 @@ export class CaldavController {
       const response = await this.caldavService.saveConfig(config);
       res.json(response);
     } catch (error) {
-      log.error({ err: error, userId: req.user?.userId }, "Error saving config");
+      log.error(
+        { err: error, userId: req.user?.userId },
+        "Error saving config",
+      );
       res.status(500).json({ error: "Failed to save config" });
     }
   }
@@ -30,7 +33,10 @@ export class CaldavController {
       // Don't expose the password to the client
       res.json(config);
     } catch (error) {
-      log.error({ err: error, userId: req.user?.userId }, "Error loading config");
+      log.error(
+        { err: error, userId: req.user?.userId },
+        "Error loading config",
+      );
       res.status(500).json({ error: "Failed to load config" });
     }
   }
@@ -40,7 +46,10 @@ export class CaldavController {
       await this.caldavService.deleteConfig(req.user!.userId);
       res.status(204).send();
     } catch (error) {
-      log.error({ err: error, userId: req.user?.userId }, "Error deleting config");
+      log.error(
+        { err: error, userId: req.user?.userId },
+        "Error deleting config",
+      );
       res.status(500).json({ error: "Failed to delete config" });
     }
   }
@@ -50,7 +59,10 @@ export class CaldavController {
       const events = await this.caldavService.pullEvents(req.user!.userId);
       res.json(events);
     } catch (error) {
-      log.error({ err: error, userId: req.user?.userId }, "Error pulling events");
+      log.error(
+        { err: error, userId: req.user?.userId },
+        "Error pulling events",
+      );
       res.status(500).json({ error: "Failed to pull events" });
     }
   }
@@ -60,7 +72,10 @@ export class CaldavController {
       await this.caldavService.pushAll(req.user!.userId);
       res.status(204).send();
     } catch (error) {
-      log.error({ err: error, userId: req.user?.userId }, "Error pushing events");
+      log.error(
+        { err: error, userId: req.user?.userId },
+        "Error pushing events",
+      );
       res.status(500).json({ error: "Failed to push events" });
     }
   }
@@ -78,7 +93,10 @@ export class CaldavController {
       await this.caldavService.pushEvent(req.user!.userId, event);
       res.status(204).send();
     } catch (error) {
-      log.error({ err: error, userId: req.user?.userId }, "Error pushing event");
+      log.error(
+        { err: error, userId: req.user?.userId },
+        "Error pushing event",
+      );
       res.status(500).json({ error: "Failed to push event" });
     }
   }

apps/server/src/controllers/EventController.ts

@@ -40,7 +40,10 @@ export class EventController {
       await this.pushToCaldav(userId, event);
       res.status(201).json(event);
     } catch (error) {
-      log.error({ err: error, userId: req.user?.userId }, "Error creating event");
+      log.error(
+        { err: error, userId: req.user?.userId },
+        "Error creating event",
+      );
       res.status(500).json({ error: "Failed to create event" });
     }
   }
@@ -67,7 +70,10 @@ export class EventController {
       const events = await this.eventService.getAll(req.user!.userId);
       res.json(events);
     } catch (error) {
-      log.error({ err: error, userId: req.user?.userId }, "Error getting events");
+      log.error(
+        { err: error, userId: req.user?.userId },
+        "Error getting events",
+      );
       res.status(500).json({ error: "Failed to get events" });
     }
   }

apps/server/src/services/AuthService.ts

@@ -44,5 +44,4 @@ export class AuthService {
 
     return { user, accessToken: "" };
   }
-
 }

apps/server/src/services/CaldavService.test.ts

@@ -1,11 +0,0 @@
-// import { createLogger } from "../logging";
-// import { CaldavService } from "./CaldavService";
-//
-// const logger = createLogger("CaldavService-Test");
-//
-// const cdService = new CaldavService();
-//
-// test("print events", async () => {
-//   const client = await cdService.login();
-//   await cdService.pullEvents(client);
-// });

apps/server/src/utils/password.test.ts

@@ -0,0 +1,37 @@
+import { hash, compare } from "./password";
+
+describe("password", () => {
+  describe("hash()", () => {
+    it("returns a valid bcrypt hash", async () => {
+      const result = await hash("testpassword");
+      expect(result).toMatch(/^\$2b\$/);
+    });
+
+    it("produces different hashes for the same password (salt)", async () => {
+      const hash1 = await hash("samepassword");
+      const hash2 = await hash("samepassword");
+      expect(hash1).not.toBe(hash2);
+    });
+  });
+
+  describe("compare()", () => {
+    it("returns true for the correct password", async () => {
+      const hashed = await hash("correct");
+      const result = await compare("correct", hashed);
+      expect(result).toBe(true);
+    });
+
+    it("returns false for a wrong password", async () => {
+      const hashed = await hash("correct");
+      const result = await compare("wrong", hashed);
+      expect(result).toBe(false);
+    });
+
+    it("handles special characters and unicode", async () => {
+      const password = "p@$$w0rd!#%& äöü 🔑";
+      const hashed = await hash(password);
+      expect(await compare(password, hashed)).toBe(true);
+      expect(await compare("other", hashed)).toBe(false);
+    });
+  });
+});

apps/server/src/utils/recurrenceExpander.test.ts

@@ -0,0 +1,210 @@
+import { CalendarEvent } from "@calchat/shared";
+import { expandRecurringEvents } from "./recurrenceExpander";
+
+// Helper: create a CalendarEvent with sensible defaults
+function makeEvent(
+  overrides: Partial<CalendarEvent> & { startTime: Date; endTime: Date },
+): CalendarEvent {
+  return {
+    id: "evt-1",
+    userId: "user-1",
+    title: "Test Event",
+    ...overrides,
+  };
+}
+
+// Helper: create a date from "YYYY-MM-DD HH:mm" (local time)
+function d(dateStr: string): Date {
+  const [datePart, timePart] = dateStr.split(" ");
+  const [y, m, day] = datePart.split("-").map(Number);
+  if (timePart) {
+    const [h, min] = timePart.split(":").map(Number);
+    return new Date(y, m - 1, day, h, min);
+  }
+  return new Date(y, m - 1, day);
+}
+
+describe("expandRecurringEvents", () => {
+  // Range: 2025-06-01 to 2025-06-30
+  const rangeStart = d("2025-06-01 00:00");
+  const rangeEnd = d("2025-06-30 23:59");
+
+  describe("non-recurring events", () => {
+    it("returns event within the range", () => {
+      const event = makeEvent({
+        startTime: d("2025-06-10 09:00"),
+        endTime: d("2025-06-10 10:00"),
+      });
+
+      const result = expandRecurringEvents([event], rangeStart, rangeEnd);
+
+      expect(result).toHaveLength(1);
+      expect(result[0].occurrenceStart).toEqual(d("2025-06-10 09:00"));
+      expect(result[0].occurrenceEnd).toEqual(d("2025-06-10 10:00"));
+    });
+
+    it("excludes event outside the range", () => {
+      const event = makeEvent({
+        startTime: d("2025-07-05 09:00"),
+        endTime: d("2025-07-05 10:00"),
+      });
+
+      const result = expandRecurringEvents([event], rangeStart, rangeEnd);
+
+      expect(result).toHaveLength(0);
+    });
+
+    it("includes event that starts before range and ends within", () => {
+      const event = makeEvent({
+        startTime: d("2025-05-31 22:00"),
+        endTime: d("2025-06-01 02:00"),
+      });
+
+      const result = expandRecurringEvents([event], rangeStart, rangeEnd);
+
+      expect(result).toHaveLength(1);
+    });
+
+    it("includes event that spans the entire range", () => {
+      const event = makeEvent({
+        startTime: d("2025-05-01 00:00"),
+        endTime: d("2025-07-31 23:59"),
+      });
+
+      const result = expandRecurringEvents([event], rangeStart, rangeEnd);
+
+      expect(result).toHaveLength(1);
+    });
+
+    it("returns empty array for empty input", () => {
+      const result = expandRecurringEvents([], rangeStart, rangeEnd);
+
+      expect(result).toEqual([]);
+    });
+  });
+
+  describe("recurring events", () => {
+    it("expands weekly event to all occurrences in range", () => {
+      // Weekly on Mondays, starting 2025-06-02 (a Monday)
+      const event = makeEvent({
+        startTime: d("2025-06-02 10:00"),
+        endTime: d("2025-06-02 11:00"),
+        recurrenceRule: "FREQ=WEEKLY;BYDAY=MO",
+      });
+
+      const result = expandRecurringEvents([event], rangeStart, rangeEnd);
+
+      // Mondays in June 2025: 2, 9, 16, 23, 30
+      expect(result).toHaveLength(5);
+      expect(result[0].occurrenceStart).toEqual(d("2025-06-02 10:00"));
+      expect(result[1].occurrenceStart).toEqual(d("2025-06-09 10:00"));
+      expect(result[2].occurrenceStart).toEqual(d("2025-06-16 10:00"));
+      expect(result[3].occurrenceStart).toEqual(d("2025-06-23 10:00"));
+      expect(result[4].occurrenceStart).toEqual(d("2025-06-30 10:00"));
+    });
+
+    it("daily event with UNTIL stops at the right date", () => {
+      const event = makeEvent({
+        startTime: d("2025-06-01 08:00"),
+        endTime: d("2025-06-01 09:00"),
+        recurrenceRule: "FREQ=DAILY;UNTIL=20250605T235959",
+      });
+
+      const result = expandRecurringEvents([event], rangeStart, rangeEnd);
+
+      // June 1, 2, 3, 4, 5
+      expect(result).toHaveLength(5);
+      expect(result[4].occurrenceStart).toEqual(d("2025-06-05 08:00"));
+    });
+
+    it("skips occurrences on exception dates (EXDATE)", () => {
+      const event = makeEvent({
+        startTime: d("2025-06-02 10:00"),
+        endTime: d("2025-06-02 11:00"),
+        recurrenceRule: "FREQ=WEEKLY;BYDAY=MO",
+        exceptionDates: ["2025-06-09", "2025-06-23"],
+      });
+
+      const result = expandRecurringEvents([event], rangeStart, rangeEnd);
+
+      // 5 Mondays minus 2 exceptions = 3
+      expect(result).toHaveLength(3);
+      const dates = result.map((r) => r.occurrenceStart.getDate());
+      expect(dates).toEqual([2, 16, 30]);
+    });
+
+    it("handles RRULE: prefix (strips it)", () => {
+      const event = makeEvent({
+        startTime: d("2025-06-01 08:00"),
+        endTime: d("2025-06-01 09:00"),
+        recurrenceRule: "RRULE:FREQ=DAILY;COUNT=3",
+      });
+
+      const result = expandRecurringEvents([event], rangeStart, rangeEnd);
+
+      expect(result).toHaveLength(3);
+    });
+
+    it("falls back to single occurrence on invalid RRULE", () => {
+      const consoleSpy = jest.spyOn(console, "error").mockImplementation();
+
+      const event = makeEvent({
+        startTime: d("2025-06-10 09:00"),
+        endTime: d("2025-06-10 10:00"),
+        recurrenceRule: "COMPLETELY_INVALID_RULE",
+      });
+
+      const result = expandRecurringEvents([event], rangeStart, rangeEnd);
+
+      expect(result).toHaveLength(1);
+      expect(result[0].occurrenceStart).toEqual(d("2025-06-10 09:00"));
+      expect(consoleSpy).toHaveBeenCalled();
+
+      consoleSpy.mockRestore();
+    });
+  });
+
+  describe("multi-day events", () => {
+    it("finds event starting before range that ends within range", () => {
+      // 3-day recurring event starting May 15, weekly
+      const event = makeEvent({
+        startTime: d("2025-05-15 08:00"),
+        endTime: d("2025-05-18 08:00"),
+        recurrenceRule: "FREQ=WEEKLY",
+      });
+
+      // The occurrence starting May 29 ends June 1 → overlaps with range
+      const result = expandRecurringEvents([event], rangeStart, rangeEnd);
+
+      const starts = result.map((r) => r.occurrenceStart.getDate());
+      // May 29 (ends June 1), June 5, 12, 19, 26
+      expect(starts).toContain(29); // May 29
+    });
+  });
+
+  describe("sorting", () => {
+    it("returns events sorted by occurrenceStart", () => {
+      const laterEvent = makeEvent({
+        id: "evt-later",
+        startTime: d("2025-06-20 14:00"),
+        endTime: d("2025-06-20 15:00"),
+      });
+      const earlierEvent = makeEvent({
+        id: "evt-earlier",
+        startTime: d("2025-06-05 09:00"),
+        endTime: d("2025-06-05 10:00"),
+      });
+
+      // Pass in reverse order
+      const result = expandRecurringEvents(
+        [laterEvent, earlierEvent],
+        rangeStart,
+        rangeEnd,
+      );
+
+      expect(result).toHaveLength(2);
+      expect(result[0].id).toBe("evt-earlier");
+      expect(result[1].id).toBe("evt-later");
+    });
+  });
+});

package.json

@@ -7,7 +7,8 @@
     "packages/*"
   ],
   "scripts": {
-    "format": "prettier --write \"apps/*/src/**/*.{ts,tsx}\" \"packages/*/src/**/*.ts\""
+    "format": "prettier --write \"apps/*/src/**/*.{ts,tsx}\" \"packages/*/src/**/*.ts\"",
+    "check_format": "prettier --check \"apps/*/src/**/*.{ts,tsx}\" \"packages/*/src/**/*.ts\""
   },
   "devDependencies": {
     "eslint": "^9.25.0",