Avoiding Unwanted Type Version Propagation

TestStand 2019 Help

Edition Date: May 2019

Part Number: 370052AA-01

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When a type conflict occurs, selecting to use the later version number of a type can propagate unwanted type versions to all instances of the type. For example, unwanted propagation might occur in the following situations:

  • You create a new version of a step type that is not compatible with previous versions of TestStand. A sequence file that contains the new type loads in a previous version of TestStand that contains an older version of the type in a type palette. In versions of TestStand earlier than version 4.1, the new version of the type automatically propagates to the type palette in the previous version of TestStand and to all files loaded in memory from then on. Because the type is not compatible with previous versions of TestStand, you might experience undesired behavior when you run sequences that use the new type.

    In TestStand 4.1 or later, by default types no longer automatically propagate to type palette files.
  • Two types with completely different functionality share the same name. When the TestStand Engine loads the two types, the engine assumes that the types are different versions of the same type and loads the type with the later version number, which can affect the functionality of the sequence files that contain instances of the second type.
  • Two different developers independently customize the same type with different changes.

Avoiding Unwanted Type Version Propagation to Previous Versions of TestStand

Because you can save sequence files to previous versions of TestStand but some types might not run correctly on previous versions of TestStand, you can specify the earliest version of TestStand that can run a type. Enable the Set Earliest TestStand Version that can Use this Type option on the Version tab of the Step Type Properties dialog box or on the Version tab of the Type Properties dialog box and set the earliest version to the current version of TestStand to prevent the current version of a type from being used in or accidentally propagated to an earlier TestStand version.

You can also create different versions of the type to run in different versions of TestStand. When you save a sequence for a previous version of TestStand, TestStand searches a set of compatibility directories to find the type version that is compatible with the previous version for which you want to save the sequence file. TestStand saves the types from the type palette files in the <TestStand>\Components\Compatibility\<version number> and <TestStand Public>\Components\Compatibility\<version number> directories with the sequence file. You can place type palette files from earlier versions of TestStand in the <TestStand Public>\Components\Compatibility\<version number> directory to ensure that TestStand saves the correct version of the types with the sequence file.


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