Migration from 2.3.1 to 3.4.2

Gatling (Open-Source)
1

Hi everyone,

I’m currently migrating a bunch of scenarii from Gatling 2.3.1 (Scala 2.12.3) to 3.4.2 (Scala 2.12.12).
I followed the migration guides (https://gatling.io/docs/current/migration_guides/), but still have compilation issues that I can’t figure out how to fix. This may be only due to my poor Scala or Gatling internals knowledge, but I can’t make it through.

Note that all this code was happily compiling and working with version 2.3.1 (for years :-)).
It may be that a prior code flaw of my own is now becoming out as a compilation error due to a stricter compilation setting / type checking / design, but I’m at loss to see why and how to fix it. :’-|

The construct having the issue is a function providing two different checks depending on the app version (small class SemanticVersion stripped from code below):

val pagename = if ( version >= SemanticVersion(“3.2.0”) ) css("#pageName") else regex("""“pageName”\s*:\s*"([^"]*)"""")

which is used such as in:

exec(http(“request”)
.get("/the/uri")
.check(pagename.is(“MY_PAGE”))

This leads to a type mismatch error:
found : io.gatling.core.check.CheckBuilder[_1,_2,String] where type _2 >: jodd.lagarto.dom.NodeSelector with String <: Object, type _1 >: io.gatling.core.check.css.CssCheckType with io.gatling.core.check.regex.RegexCheckType <: Object
required: io.gatling.http.check.HttpCheck

Looks like the type inference is fumbling - or should I explicitly declare the return type for the pagename function? And which type, then?

I tried explicitly declaring the return type to an HttpCheck:
val pagename : HttpCheck = if ( version >= SemanticVersion(“3.2.0”) ) pagenameVersion32OrMore else pagenameVersion31OrLess

But then:
value is is not a member of io.gatling.http.check.HttpCheck

Any clue, anyone?

Thanks a million
Pascal D

2

Not sure what is happening, could you try forcing the type of pagename to HttpCheck and import io.gatling.http.check.HttpCheck?

3

Not sure what is happening, could you try forcing the type of pagename to HttpCheck and import io.gatling.http.check.HttpCheck?

Did that already, but not working:

4

Oh sorry I read half the message… let me investigate.

5

That’s not possible.
The intermediate steps of the check DSL don’t share a common super type.
For example, “css” has a different “ofType” than “regex”.

The only thing you can do is something like:

val pagename**: HttpCheck** = if ( version >= SemanticVersion(“3.2.0”) ) css("#pageName").is(“foo”) else regex("""“pageName”\s*:\s*"([^"]*)"""").is(“foo”)

6

That’s not possible.
The intermediate steps of the check DSL don’t share a common super type.
For example, “css” has a different “ofType” than “regex”.

Ah! Ok, that makes a lot of sense.
Now for the sake of understanding, I’m wondering why it did work with version 2.3.x… Internal classes design changed with 3.x ?

The only thing you can do is something like:

val pagename**: HttpCheck** = if ( version >= SemanticVersion(“3.2.0”) ) css(“#pageName”).is(“foo”) else regex(“”““pageName”\s*:\s*”([^“]*)”“”").is(“foo”)

Ok, will make the function having a parameter to perform the check as described.
Will let you know how this goes.

Pascal D

7

Now for the sake of understanding, I’m wondering why it did work with version 2.3.x… Internal classes design changed with 3.x ?

Exactly

8

Ok, that explains it. :slight_smile:
Performed the said changes - everything is now working ok.
Thanks a lot!