Back in June, Politifact did a breakdown that I thought was pretty fair. It highlights some small infractions by Iran, but shows that for the most part Iran has been compliant. Bear in mind this article is old.

http://www.politifact.com/georgia/statements/2017/jun/14/karen-handel/iran-complying-nuclear-deal-yes-small-hiccups/

[quote]"While the IAEA has certified Iran’s compliance in its quarterly reports, Iran’s record is not without blemishes. The Handel campaign zeroed in on those.

Handel’s campaign aide pointed us to news reports and congressional testimony that highlighted instances where Iran committed two small infractions of a highly technical nature.

The deal says Iran can keep 130 metric tons of "heavy water," a modified liquid used in some nuclear reactors. However, Iran has twice crept over its limit, according to the IAEA, each time by a fraction of one ton.

These breaches formed the core basis of Handel’s claim that Iran violated the nuclear deal. Some experts we spoke to said Iran has tried to create wiggle room by interpreting portions of the agreement to favor their own interests. But the clear consensus is that it overstates the case to say Iran has violated the deal."[/quote]

[quote]"Daryl Kimball, the executive director Arms Control Association, downplayed the heavy water issue as a "minor infraction," and noted that Iran currently does not have a functioning heavy water reactor. In other words, from a practical standpoint, the issue is essentially moot because excessive heavy water wouldn’t move Iran closer to building a nuclear weapon."[/quote]

[quote]"Several experts also noted Iran quickly rectified its breach to come back into compliance."[/quote]

In short, the infractions Iran has committed are so small and technical, that it would be a reach to say they violated the deal.