String comparison bug with invisible character (It's more of a story than a question)

[Seb_]

Hi everybody!

Here is a story/testimony of what happened to me while building a flow. It’s a bit long and I don’t even need help because I finally figured why I had a problem, but someone might find this useful, and others might have explanation of how it happened! Good read!

I'm fairly new to Power automate, I created a few successful flows for my company, but yesterday I encountered a bug (I guess you could call that a bug).

Let me give you context:

In my company we use Microsoft forms to make internal audits. Until today, we had a simple planning on excel that specifies who, where and when an audit must be made. I wanted to automate the whole process to verify if the audits are done or if someone’s late using power automate. To do that, I recreated the planning in a SharePoint List, which also specifies the person, the date, the zone of the audit. The different zones are stocked in another List and in the main one you have a lookup column. The idea is to update the “planning list” when a audit is made

To be able to compare the MS Forms with the Lists, I copy pasted some values to populate the answer options between the SP lists and the MS forms, and their might have been a few corrections or modifications at the same time, but in the end, the values/strings where VISIBLY identical. Even when copy pasted in a text file, you couldn’t see any difference (I specify that because that’s the first thing I did when trying to understand the issue).

Basically, my flow works like that:

I get the forms response, I filter the get the list entry corresponding to the audit (I have a field that specifies if the audits were done or not) with a first filter for the “Done or not” column, the persons column, and the zone column:

Then, I order the results by ascending due date, and top count is set to 1 so I only get the list line that corresponds the very next planned audit, or one that would be late. (last step is to update this list item by changing the “done or not” status).

Long story short, this filter step compares different values to get the correct list item, and this is where the issue happened: I compare the answer value of the forms where there’s a dropdown selection, that was populated with copy pastes, to a value in the lookup field that was ALSO populated with a copy paste. But somehow, the comparison didn’t work even if the logs showed that it should have worked because the result string used in the filter query is VISIBILY identical to the targeted line in the list.

After a few hours of search and comparison with another flow that does the same thing but with another form and another list (that works), I noticed that there was a strange character in my filter string in some of the logs:

(Sorry for the poor quality)

You can see that there’s a space between the “:” and the “Bureaux”. When copy pasted in a text file to compare the strings, there’s nothing visible, but this character behaved DIFFERENTLY than the other spaces and made the comparison impossible to match.

Once this orange square was noticed, I retyped and recopy pasted the strings in the form and in the list and it solved the issue.

So that’s the end of the story. I don’t really have a question except, what is that and how could it have happened?

I hope you found this at least interesting, and if you want some details on my flow because it might be useful, don’t hesitate! There were a few specificities that made the flow not as straight forward as expected, like the fact that the form was not visible in the dropdown list because its stored on a SharePoint site and not on my personal space, and the lookup columns comparison is a bit touchy and isn’t directly available in the dynamic contents !

[Expiscornovus]

Hi @Seb_,

I have seen a couple instances in the past where Microsoft Forms has put an accidental leading or trailing white space character in the answer of a choice question type of field.

What I typically do to handle this is use a trim function in an expression.