Forum Discussion

gus's avatar
gus
Contributor
9 years ago

What's wrong with this throw statement in JScript?

See the following code, copied from the else block of an if statement in a JScript script:   var err = new Error(); err.number = 1; err.name = "Could not close running Foo instance"; Log.Error(err....
  • k_de_boer03's avatar
    k_de_boer03
    9 years ago

    I believe your code works as you intended. However keep this in mind:

     

    In TestComplete, if a script calls an object method that is declared in another unit, and this method throws an exception, the exception cannot be caught and handled by the try {} block in the main script. Keep this in mind when developing object-oriented test scripts using native JScript functionality.

     

    Source: https://support.smartbear.com/viewarticle/70308/

     

    Check the example code under header "Using Objects Defined in Other Units".

     

    I try to avoid exceptions and instead use event handlers because of this.

     

     

NisHera's avatar
NisHera
Valued Contributor

 

the structure of code is not correct.

first you should throw error and do something with that...

once you throw error it go as a run time error witch has to handle

 

I would rather confined to Log.error (it would not crash test ) which gives a TC error and run rest of test

Or throw error withing try catch statement and in catch Log the error

 

eg

function abcd(){
var err = new Error();
err.number = 1;
err.description = "Could not close running Foo instance";
try
{
  throw err;
}
catch (err)
{
Log.Error(err.number, err.description);
}}

 

gus's avatar
gus
Contributor
9 years ago

Hi,

 

Thanks for the detailed explanation! Understanding that the practice applied is not correct, I'd like to ask to suggest a pattern for the case when I want to let the caller of a routing be able to handle errors in try catch blocks.

 

function foo() {
  try {
     // do something
     bar();
  } catch (x) {
     // do something when bar() throwed an exception
  }
)

funtion bar() {
  // do something
  if (someCondition) {
    throw new Error(...);
  }
}

What I'd like is foo() to be able to catch the signal generated in bar(). Will the throw statement in bar() result in runtime error even if it is handled above in the call stack?

  • k_de_boer03's avatar
    k_de_boer03
    Contributor
    9 years ago

    I believe your code works as you intended. However keep this in mind:

     

    In TestComplete, if a script calls an object method that is declared in another unit, and this method throws an exception, the exception cannot be caught and handled by the try {} block in the main script. Keep this in mind when developing object-oriented test scripts using native JScript functionality.

     

    Source: https://support.smartbear.com/viewarticle/70308/

     

    Check the example code under header "Using Objects Defined in Other Units".

     

    I try to avoid exceptions and instead use event handlers because of this.

     

     

    • gus's avatar
      gus
      Contributor
      9 years ago

      Thanks for reminding about the cross-unit problem of throwing exceptions! I remember I read it a few times, but forgot completely. :)

       

      Maybe such functions should return an Error object, which works, but looks way ugly. :)