TestCheckNull (Function)

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WLanguage functions

Standard functions

Test functions

TestCheckNull

Presentation

Example

Operating mode

Managing assertions

See also

TestCheckNull (Function)

In french: TestVérifieNull

Checks whether an expression is Null in assertive programming and in automated test mode.

Remark: This function is equivalent to dbgCheckNull.

Example

// If FindCustomer is a procedure used to find a customer identified by its name and that returns
// the CCustomer object corresponding to the customer if the customer is known and Null otherwise
// A customer who already exists must not be added
TestCheckNull(FindCustomer(CustomerName), "Customer '%1' is already known", CustomerName)
// Adds the customer
AddCustomer(CustomerName)

Syntax

TestCheckNull(<Expression> [, <Comments> [, <Parameter 1> [... [, <Parameter N>]]]])

<Expression>: Character string

Expression that must be checked.

<Comments>: Character string

Character string in the format defined by StringBuild.

<Parameter 1>: Any type

First parameter expected by <Comments>.

<Parameter N>: Any type

Nth parameter expected by <Comments>.

Remarks

Operating mode

When the expression is not Null:

in automated test mode, an error is added to the test status report (equivalent to TestWriteResult).
in manual test mode, an assertion is displayed (equivalent to dbgAssert).
in runtime mode, an assertion is displayed if the assertions have been enabled (equivalent to dbgAssert).

When running an application, the expression is not evaluated if the assertions are not enabled.

dbgOnError allows you to automatically start a WLanguage procedure used to retrieve the comment linked to the error.

Managing assertions

The messages of TestCheckNull will be written into the ADB log (at "Assert" level). For more details, see Managing ADB logs.

Component: wd270vm.dll