Testing variables

Component Testing for C

One of the main features of Component Testing for C is its ability to compare initial values, expected values and actual values of variables during test execution. In the C Test Script Language, this is done with the VAR statement.

The VAR statement specifies both the test start-up procedure and the post-execution test for simple variables. This instruction uses three parameters:

Name of the variable under test: this can be a simple variable, an array element, or a field of a record. It is also possible to test an entire array, part of an array or all the fields of a record.
Initial value of the variable: identified by the keyword INIT.
Expected value of the variable after the procedure has been executed: identified by the keyword EV.

Declare variables under test with the VAR statement, followed by the declaration keywords:

INIT = for an assignment
INIT == for no initialization
EV = for a simple test.

It does not matter where the VAR instructions are located with respect to the test procedure call since the C code generator separates VAR instructions into two parts :

The variable test is initialized with the ELEMENT instruction
The actual test against the expected value is done with the END ELEMENT instruction

Many other forms are available that enable you to create more complex test scenarios.

Using C Expressions

Component Testing for C allows you to define initial and expected values with standard C expressions.

All literal values, variable types, functions and most operators available in the C language are accepted by Component Testing for C.

Example

The following example demonstrates typical use of the VAR statement

HEADER add, 1, 1

#with add;

BEGIN

SERVICE add

# a, b, c : integer;

TEST 1

FAMILY nominal

ELEMENT

VAR a, init = 1, ev = init

VAR b, init = 3, ev = init

VAR c, init = 0, ev = 4

#c := add(a,b);

END ELEMENT

END TEST

END SERVICE