I can´t recall that IS has committed a terrorist attack on Israel. Why is that the case?
tl;dr: too much competition.
IS terrorist attacks usually have these goals:
- Retaliation for attacks on IS-controlled territory
- Provoking western societies to discriminate against Muslims, so the Muslims feel ostracized, can be radicalized and recruited as terrorists.
- Gaining media attention.
Israel is not attacking the IS so there is nothing to retaliate against.
Israel is already discriminating against Muslims (Palestinians) as much as they can and as a result many Palestinians are already radicalized by the Hamas and other Palestinian terrorist groups. A Palestinian who wants to take part in the Jihad would likely rather join one of these local groups than the IS.
Another factor which makes Israel unattractive as a terrorist target is that Israel is already targeted a lot by the Palestinian terrorist groups. Terrorist attacks are almost an everyday occurrence by now, which makes the population quite dulled to them. While a terrorist attack in the rather peaceful Europe is a very uncommon event and occupies media and politics for weeks, it's barely worth reporting in Israel. The attack would likely just get attributed to one of the Palestinian terrorist groups anyway. So there is not much attention to gain either.
Because the Palestinian organisations dominating Gaza and the West Bank are too secular and Nationalist for IS tastes. Their struggle is first and foremost against the Israeli occupation with the goal of creating their own state. IS on the other hand is Internationalist as they fight for a global caliphate under which all Muslims believing in their version of Islam would be united. Nationalism and Internationalism are on opposite sides in one aspect of the political spectrum.
Their relationship between IS and the Palestinian organisations has shifted from lukewarm to downright hostile at times. Like last year when Hamas arrested dozens of IS-supporters which was a response to direct threat by IS towards them:
"We will uproot the state of the Jews [Israel] and you [Hamas] and Fatah, and all of the secularists are nothing and you will be overrun by our creeping multitudes," ... "The rule of sharia [Islamic law] will be implemented in Gaza, in spite of you. We swear that what is happening in the Levant today, and in particular the Yarmouk camp, will happen in Gaza,"
Hamas implements a form of Sharia in Gaza but it is not strict enough in IS's views and therefore they are the enemies and need to be fought.
The thing with fundamentalists is that their worst enemies aren't those with completely different ideas from themselves but those who hold slightly different views. It's true of Christian fundamentalists, Jewish fundamentalists, Muslim fundamentalists, political fundamentalists... For example, during the Cold War China was at times a bigger threat to the Soviet Union than the United States due to their somewhat different interpretations of what Communism meant.
IS surely would like to attack Israel but doing so would be a challenge to Hamas' and Fatah's authority and they aren't strong enough yet.
Currently, they are trying to establish themselves in Gaza. They haven't accomplished much yet, but they are firing a few rockets into Israel now and then. The point of those rockets aren't to cause terror but to win support from the local population as some (how many are impossible to say) are dissatisfied with the cease-fire Hamas has adhered to. Gradually they will try and build their standing and when they are confident, they will try and take over Gaza in a violent with Hamas.