WEBVTT

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So, we get some routes for accepting and deleting reservations, but of course there's no business

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logic in there.

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Now it would make sense to validate any submitted data, to make sure that a valid time and date

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was submitted, a valid number of people, and to then maybe store that data in a database.

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So what we could do is write another prompt here, refer to that file to be safe, though

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it should normally consider the open file, but anyways, and then after adding this context

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here say, validate the received input and store it in the database.

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Now again, if I write it like this, that's very unspecific, so I'll get a reply, but

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chances are that the reply is not really that great, that it's not really what I want.

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And there also is another problem with this prompt here, it's not just not very specific,

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it also asks for a lot.

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I want to validate the received input and store it in a database, and both problems

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are more or less complex.

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For example, validating the input, I could add way more information here, which input

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to validate, what to validate it for, so what my conditions, my criteria are.

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And the same for a database, which database, which data should get stored there, and so

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on.

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So this is a short prompt for a complex problem, and you want to avoid prompts like this.

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You want to split them up into multiple problems and into multiple prompts instead, typically.

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Because here I'm getting back some code, but I'm not sure if it's really the code I

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want.

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And indeed here, if you take a closer look at the code it generated here, you can see

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that regarding that database storage part, it did not generate any code for that.

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It just assumes that there is a reservation model in a models folder in a reservation

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file, but that's a file you would have to create, and that's a model you would have

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to create as well.

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It does not exist here in this project.

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So it assumes that this is there, and that this then will store the data in the database.

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So if you just apply this code and run it, it simply won't work.

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It also assumes that the express validator package is installed, which is also not the

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case.

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So as you can tell, here it generated some code, which wouldn't work, which would require

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a couple of extra steps that are not mentioned here in the response.

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And that's why you want to avoid unspecific, complex, multi-problem prompts like this typically.

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Instead you can open a new chat, or use the inline chat here actually, and select this

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code here, because ultimately that's what I want to validate.

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And then just say add code to validate this input.

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Don't use an external library.

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Number of people should be between 1 and 6, let's say.

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Time should be between 5 p.m. and let's say 11 p.m., only every 30 minutes.

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Date should be today or in the future.

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And now I'll actually add some extra examples regarding the time, because what I want to

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allow is that people can book 5 p.m. or 5.30, 6 p.m. or 6.30, but not quarter past five

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or 5.10 or anything like that.

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So I'll add some extra examples regarding the time.

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People should be allowed to book 5, 5.30, 6, 6.30, and so on, but not 5.10, 5.15, etc.

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So I'm adding some examples here to add more context in the end to the prompt to hopefully

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get exactly the code I'm looking for.

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So let's hit enter, and this is a rather complex task now, so let's see what it generates.

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Generates a bunch of code and looks like it's done.

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So what it's doing here is still extracting.

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the data from the body, then it's checking the number of people, if it's

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not a number or if it's a number smaller than one or greater than six in

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which case it returns an error response, then it validates the time and here it

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simply hardcodes the available time slots which I guess makes sense because

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it really isn't that many 5 p.m. till 11 p.m. so it does that in the 24-hour

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format which is fine by me and then it checks whether the valid times array

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includes the time that was submitted with the request and if that's not the

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case it will return an error response and for the date it gets the current

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date and converts the received date to a date object and then it sets the hours

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of today to the start of the day and then checks if the timestamp in

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milliseconds of the input date is maybe not a number or if it's smaller than

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today if the input data is smaller than today and in either case it sends back a

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response. Now we should definitely test this code to make sure it really works

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the way it should but it looks good to me so I'll accept this and this shows

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you how now we got a vastly different code than what I had before in the chat

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so this is what it generated before it just assumed that there was some

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validation library and it also ran different kinds of validation now we get

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a much better result because we were more specific we added specific useful

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context and we added examples and that's why prompt engineering matters once you

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know it it's obvious but it's easy to forget or to not even be aware of the

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importance of being specific of providing examples and of really

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controlling which kinds of results the AI will generate for you