Fix parsing of connectionTimeout setting

Connection timeout limits amount of time connection spends waiting for
the remote side to respond. It makes connect not hang forever if remote
side does not respond. Configured positive values define the actual
timeout. Zero and negative values mean infinite timeout.

Previously configured value was not correctly interpreted and thus it
was not possible to disable the timeout. Zero and negative values
resulted in a default value of 5 seconds to be used.

This commit fixes the problem so that zero and negative values mean
no timeout.

Author: lutovich

src/v1/index.js

@@ -144,9 +144,9 @@ const USER_AGENT = "neo4j-javascript/" + VERSION;
  *       // version.
  *       loadBalancingStrategy: "least_connected" | "round_robin",
  *
- *       // Specify socket connection timeout in milliseconds. Non-numeric, negative and zero values are treated as an
- *       // infinite timeout. Connection will be then bound by the timeout configured on the operating system level.
- *       // Timeout value should be numeric and greater or equal to zero. Default value is 5000 which is 5 seconds.
+ *       // Specify socket connection timeout in milliseconds. Numeric values are expected. Negative and zero values
+ *       // result in no timeout being applied. Connection establishment will be then bound by the timeout configured
+ *       // on the operating system level. Default value is 5000, which is 5 seconds.
  *       connectionTimeout: 5000, // 5 seconds
  *     }
  *

src/v1/internal/ch-config.js

@@ -68,8 +68,17 @@ function extractKnownHostsPath(driverConfig) {
 
 function extractConnectionTimeout(driverConfig) {
   const configuredTimeout = parseInt(driverConfig.connectionTimeout, 10);
-  if (!configuredTimeout || configuredTimeout < 0) {
+  if (configuredTimeout === 0) {
+    // timeout explicitly configured to 0
+    return null;
+  } else if (configuredTimeout && configuredTimeout < 0) {
+    // timeout explicitly configured to a negative value
+    return null;
+  } else if (!configuredTimeout) {
+    // timeout not configured, use default value
     return DEFAULT_CONNECTION_TIMEOUT_MILLIS;
+  } else {
+    // timeout configured, use the provided value
+    return configuredTimeout;
   }
-  return configuredTimeout;
 }

test/internal/ch-config.test.js

@@ -117,4 +117,16 @@ describe('ChannelConfig', () => {
     expect(config.connectionTimeout).toEqual(424242);
   });
 
+  it('should respect disabled connection timeout with value zero', () => {
+    const config = new ChannelConfig(null, {connectionTimeout: 0}, '');
+
+    expect(config.connectionTimeout).toBeNull();
+  });
+
+  it('should respect disabled connection timeout with negative value', () => {
+    const config = new ChannelConfig(null, {connectionTimeout: -42}, '');
+
+    expect(config.connectionTimeout).toBeNull();
+  });
+
 });