Code
ON *:TEXT:whatever:#channel: {
  IF(1==1) {Command1 | Command2 }        ; | TestCommand3 }
  AlwaysCommand
}
You have multiple issues in your example.

1. The "IF" cannot touch the "(".
2. The "==" cannot touch the numbers.
3. The "{" cannot touch the "Command1".

Fixed example:
Code
ON *:TEXT:whatever:#channel: {
  IF (1 == 1) { Command1 | Command2 }        ; | TestCommand3 }
  AlwaysCommand
}