bun.sh/test/js/valkey/reliability/connection-failures.test.ts

import { RedisClient } from "bun";
import { describe, expect, mock, test } from "bun:test";
import { DEFAULT_REDIS_OPTIONS, DEFAULT_REDIS_URL, delay, isEnabled } from "../test-utils";

/**
 * Test suite for connection failures, reconnection, and error handling
 * - Connection failures
 * - Reconnection behavior
 * - Timeout handling
 * - Error propagation
 */
describe.skipIf(!isEnabled)("Valkey: Connection Failures", () => {
  // Use invalid port to force connection failure
  const BAD_CONNECTION_URL = "redis://localhost:12345";

  describe("Connection Failure Handling", () => {
    test("should handle initial connection failure gracefully", async () => {
      // Create client with invalid port to force connection failure
      const client = new RedisClient(BAD_CONNECTION_URL, {
        connectionTimeout: 500, // Short timeout
        autoReconnect: false, // Disable auto reconnect to simplify the test
      });

      try {
        // Attempt to send command - should fail with connection error
        await client.set("key", "value");
        expect(false).toBe(true); // Should not reach here
      } catch (error) {
        // Expect an error with connection closed message
        expect(error.message).toMatch(/connection closed|socket closed|failed to connect/i);
      } finally {
        // Cleanup
        await client.close();
      }
    });

    test("should reject commands with appropriate errors when disconnected", async () => {
      // Create client with invalid connection
      const client = new RedisClient(BAD_CONNECTION_URL, {
        connectionTimeout: 500,
        autoReconnect: false,
        enableOfflineQueue: false, // Disable offline queue to test immediate rejection
      });

      // Verify the client is not connected
      expect(client.connected).toBe(false);

      // Try commands individually to make sure they fail properly
      try {
        await client.get("any-key");
        expect(false).toBe(true); // Should not reach here
      } catch (error) {
        // Should fail with connection error
        expect(error.message).toMatch(/connection closed|socket closed|failed to connect|offline queue is disabled/i);
      }

      try {
        await client.set("any-key", "value");
        expect(false).toBe(true); // Should not reach here
      } catch (error) {
        // Should fail with connection error
        expect(error.message).toMatch(/connection closed|socket closed|failed to connect|offline queue is disabled/i);
      }

      try {
        await client.del("any-key");
        expect(false).toBe(true); // Should not reach here
      } catch (error) {
        // Should fail with connection error
        expect(error.message).toMatch(/connection closed|socket closed|failed to connect|offline queue is disabled/i);
      }

      try {
        await client.incr("counter");
        expect(false).toBe(true); // Should not reach here
      } catch (error) {
        // Should fail with connection error
        expect(error.message).toMatch(/connection closed|socket closed|failed to connect|offline queue is disabled/i);
      }
    });

    test("should handle connection timeout", async () => {
      // Use a non-routable IP address with a very short timeout
      const client = new RedisClient("redis://192.0.2.1:6379", {
        connectionTimeout: 2, // 2ms second timeout
        autoReconnect: false,
      });
      expect(async () => {
        await client.get("any-key");
      }).toThrowErrorMatchingInlineSnapshot(`"Connection timeout reached after 2ms"`);
    });

    test("should report correct connected status", async () => {
      // Create client with invalid connection
      const client = new RedisClient(BAD_CONNECTION_URL, {
        connectionTimeout: 500,
        autoReconnect: false,
      });

      // Should report disconnected state
      expect(client.connected).toBe(false);

      try {
        // Try to send command to ensure connection attempt
        await client.get("key");
      } catch (error) {
        // Expected error
      }

      // Should still report disconnected
      expect(client.connected).toBe(false);

      await client.close();
    });
  });

  describe("Reconnection Behavior", () => {
    // Use a shorter timeout to avoid test hanging
    test("should reject commands when offline queue is enabled", async () => {
      // Create client with invalid connection but with offline queue enabled
      const client = new RedisClient(BAD_CONNECTION_URL, {
        connectionTimeout: 100, // Very short timeout
        autoReconnect: false, // Disable auto-reconnect to avoid waiting for retries
        enableOfflineQueue: true,
      });

      // Try to send a command - it should be queued but eventually fail
      // when the connection timeout is reached
      const commandPromise = client.set("key1", "value1");

      try {
        await commandPromise;
        expect(false).toBe(true); // Should not reach here
      } catch (error) {
        // Should fail with a connection error
        expect(error.message).toMatch(/connection closed|socket closed|failed to connect/i);
      }

      await client.close();
    });

    test("should reject commands when offline queue is disabled", async () => {
      // Create client with invalid connection and offline queue disabled
      const client = new RedisClient(BAD_CONNECTION_URL, {
        connectionTimeout: 500,
        autoReconnect: true,
        enableOfflineQueue: false,
      });

      try {
        // Try to send command - should reject immediately
        await client.set("key", "value");
        expect(false).toBe(true); // Should not reach here
      } catch (error) {
        expect(error.message).toMatch(/connection closed|offline queue is disabled/i);
      }

      await client.close();
    });

    // Skip this test since it's hard to reliably wait for max retries in a test environment
    test.skip("should stop reconnection attempts after max retries", async () => {
      // This test is unreliable in a test environment, as it would need to wait
      // for all retry attempts which could cause timeouts
    });
  });

  describe("Connection Event Callbacks", () => {
    // Only test this if Redis is available
    test("onconnect and onclose handlers", async () => {
      // Try connecting to the default Redis URL
      const client = new RedisClient(DEFAULT_REDIS_URL, DEFAULT_REDIS_OPTIONS);

      // Set up event handlers
      const onconnect = mock(() => {});
      const onclose = mock(() => {});
      client.onconnect = onconnect;
      client.onclose = onclose;
      await client.set("__test_key", "test-value");

      // If we get here, connection succeeded, so we should check connect callback
      expect(client.connected).toBe(true);
      expect(onconnect).toHaveBeenCalled();

      // Explicitly disconnect to trigger onclose
      client.close();

      // Wait briefly for disconnect callbacks to execute
      await delay(10);

      // onclose should be called regardless of whether the connection succeeded
      expect(client.connected).toBe(false);
      expect(onclose).toHaveBeenCalled();

      expect(onconnect).toHaveBeenCalledTimes(1);
      expect(onclose).toHaveBeenCalledTimes(1);
    });
    test("should support changing onconnect and onclose handlers", async () => {
      const client = new RedisClient(DEFAULT_REDIS_URL, DEFAULT_REDIS_OPTIONS);

      // Create mock handlers
      const onconnect1 = mock(() => {});
      const onclose1 = mock(() => {});
      const onconnect2 = mock(() => {});
      const onclose2 = mock(() => {});

      // Set initial handlers
      client.onconnect = onconnect1;
      client.onclose = onclose1;

      // Change handlers
      client.onconnect = onconnect2;
      client.onclose = onclose2;

      try {
        // Try to initialize connection
        await client.set("__test_key", "test-value");
      } catch (error) {
        // Connection failed, but we can still test onclose
      }

      // Disconnect to trigger close handler
      await client.close();

      // Wait briefly for the callbacks to execute
      await delay(10);

      // First handlers should not have been called because they were replaced
      expect(onconnect1).not.toHaveBeenCalled();
      expect(onclose1).not.toHaveBeenCalled();

      // Second handlers should have been called
      expect(onclose2).toHaveBeenCalled();

      // If connection succeeded, the connect handler should have been called
      if (client.connected) {
        expect(onconnect2).toHaveBeenCalled();
      }
    });
  });

  describe("Handling Manually Closed Connections", () => {
    test("should not auto-reconnect when manually closed", async () => {
      // Set up a client
      const client = new RedisClient(DEFAULT_REDIS_URL, {
        ...DEFAULT_REDIS_OPTIONS,
        autoReconnect: true,
      });

      // Try to initialize connection
      await client.set("__test_key", "test-value");

      // Manually disconnect
      client.close();

      // Try to send a command
      expect(client.connected).toBe(false);
      expect(async () => {
        await client.get("__test_key");
      }).toThrowErrorMatchingInlineSnapshot(`"Connection has failed"`);
      // Wait some time to see if auto-reconnect happens
      await delay(50);

      // Should still be disconnected
      expect(client.connected).toBe(false);
    });

    test("should clean up resources when disconnected", async () => {
      // Create a client with no auto reconnect to simplify test
      const client = new RedisClient(BAD_CONNECTION_URL, {
        autoReconnect: false,
        connectionTimeout: 100,
      });

      // Disconnect immediately
      await client.close();

      expect(client.connected).toBe(false);
      expect(async () => {
        await client.get("any-key");
      }).toThrowErrorMatchingInlineSnapshot(`"Connection closed"`);
      // Multiple disconnects should not cause issues
      await client.close();
      await client.close();
    });
  });

  describe("Multiple Connection Attempts", () => {
    test("should handle rapid connection/disconnection", async () => {
      // Create and immediately disconnect many clients
      const promises = [];

      for (let i = 0; i < 10; i++) {
        const client = new RedisClient(DEFAULT_REDIS_URL, {
          ...DEFAULT_REDIS_OPTIONS,
          connectionTimeout: 500,
        });

        // Immediately disconnect
        promises.push(client.close());
      }

      // All should resolve without errors
      await Promise.all(promises);
    });

    test("should not crash when connections fail", async () => {
      // Create multiple clients with invalid connections in parallel
      const clients = [];

      for (let i = 0; i < 5; i++) {
        clients.push(
          new RedisClient(BAD_CONNECTION_URL, {
            connectionTimeout: 200,
            autoReconnect: false,
          }),
        );
      }

      // Try sending commands to all clients
      const promises = clients.map(client =>
        client.get("key").catch(err => {
          // We expect errors, but want to make sure they're the right kind
          expect(err.message).toMatch(/connection closed|socket closed|failed to connect/i);
        }),
      );

      // All should reject without crashing
      await Promise.all(promises);

      // Clean up
      for (const client of clients) {
        await client.close();
      }
    });
  });
});