Abstract:
Provided are a method and apparatus for evaluating the effectiveness of a test case used for a program test on the basis of error detection capability. The method includes: receiving a target program used for evaluating the effectiveness of the test case; generating an error program by inputting errors to the target program; detecting the errors by executing the test case on the generated error program; and calculating evaluation points of the test case using a ratio of the number of the detected errors to the number of the input errors. Thus, the capability of the test case used for a program test to detect errors can be evaluated.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 2007-95525, filed Sep. 19, 2007, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates to program test technology and, more particularly, to a method and apparatus for evaluating the effectiveness of a test case used for a program test. 
     2. Discussion of Related Art 
     Conventional embedded systems are mostly employed for simple repetitive work, but they have recently been applied in more various fields, for example, portable phones, automobiles, medical equipment, and various electronic devices. In addition, since the safety of embedded systems significantly affects the commercial availability of products, not only development and production processes, but also inspection processes are accepted as critical. In particular, a program test for inspecting the quality of a program (e.g., a device driver) embedded in an embedded system and a program test for inspecting the quality of hardware of the embedded system are becoming more important. 
     A program test includes executing test cases on a test target program and determining if the test target program is properly embodied based on the execution result. Accordingly, it is important to evaluate the effectiveness of the test case used for the program test. 
     However, a conventional program test is performed without evaluating the capability of a test case to detect errors. In other words, the test case is executed on a test target program irrespective of the error detection capability of the test case, so that the test case is only evaluated depending on whether the test case performs all source codes of the test target program or all branch statements of the test target program. 
     Especially, in the case of a device driver, content to be tested and detected errors vary with the usable environment of an embedded system including the device driver. However, since conventional evaluation systems evaluate test cases based on equal standards, it is difficult to evaluate the test cases based on specific standards appropriate for the usable environment of the device driver. 
     Therefore, it is necessary to develop a new technique of evaluating the error detection capability of a test case used for a program test. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a method and apparatus for evaluating the effectiveness of a test case on the basis of error detection capability. 
     One aspect of the present invention provides a method for evaluating effectiveness of a test case. The method includes: receiving a target program used for evaluating the effectiveness of the test case; generating an error program by inputting errors to the target program; detecting the errors by executing the test case on the generated error program; and calculating evaluation points of the test case using a ratio of the number of the detected errors to the number of the input errors. 
     Another aspect of the present invention provides an apparatus for evaluating effectiveness of a test case. The apparatus includes: a program test module including an error program generator and an error detector, wherein the error program generator receives a target program used for evaluating the effectiveness of the test case and inputs errors to the target program to generate an error program, and the error detector executes the test case on the generated error program to detect the errors; and an evaluation point calculation module for calculating evaluation points of the test case using a ratio of the number of the detected errors to the number of the input errors. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
         FIG. 1  is a block diagram of an effectiveness evaluation unit of a test case according to an exemplary embodiment of the present invention; and 
         FIG. 2  is a flowchart illustrating a method for evaluating the effectiveness of a test case according to an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIG. 1  is a block diagram of an effectiveness evaluation unit of a test case according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 1 , the effectiveness evaluation unit of the test case includes a program test module  100 , an evaluation point calculation module  110 , and a storage module  120 . Hereinafter, the construction and operation of the effectiveness evaluation unit of the test case according to the exemplary embodiment of the present invention will be described in detail with reference to  FIG. 1 . 
     The program test module  100  includes an error program generator  102  and an error detector  104 . The error program generator  102  inputs errors to a target program and generates an error program, and the error detector  104  detects errors from the generated error program. 
     The target program is used for evaluating the test case. In the present embodiment, when errors are input to the target program, the error program is generated. 
     The error program generator  102  receives the target program used for evaluating the effectiveness of the test case, inputs errors to the target program to generate the error program, and outputs the generated error program to the error detector  104 . 
     Also, the error program generator  102  may receive at least one type of error among predetermined types of errors, input the received types of errors to the target program, and generate an error program. 
     Errors to be input to the target program may include, for example, an ambiguity error and a contradiction error. The ambiguity error may be transferred to at least two states when an equal incident occurs under an equal condition, and the contradiction error describes impossible conditions. For brevity, a description of various other errors that may occur in programs will be omitted here. However, the above-described ambiguity error and contradiction error will now be described in detail with specific examples. 
     The ambiguity error will be described in more detail with reference to Table 1. 
     
       
         
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Present state 
                 Condition 
                 Next state 
               
               
                   
               
             
             
               
                 S1 
                 A == 5 
                 S1 
               
               
                   
                 A == 5 &amp;&amp; B == 3 
                 S2 
               
               
                   
               
             
          
         
       
     
     Referring to Table 1, in the present state ‘S1’, when A is 5 and B is 3, both of two conditions shown in Table 1 are satisfied. Accordingly, a system cannot determine if the next state should remain to be the state ‘S1’ as in the present state or be changed to a state ‘S2’. 
     The contradiction error will be described in more detail with reference to Table 2. 
     
       
         
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Present state 
                 Condition 
                 Next state 
               
               
                   
               
             
             
               
                 S1 
                 A &gt; 5 &amp;&amp; A &lt; 5 
                 S2 
               
               
                 S1 
                 B == 3 || B! = 3 
                 S2 
               
               
                   
               
             
          
         
       
     
     Referring to Table 2, in the present state ‘S1’, since none satisfies a first condition where A is larger than 5 and simultaneously smaller than 5, a system makes an error during processing of a program to which the first condition is input. Similarly, it is impossible to satisfy a second condition where B is 3 and simultaneously is not 3, so that the system makes an error during processing of a program to which the second condition is input. 
     Referring again to  FIG. 1 , the error program generator  102  may load an error generation engine corresponding to the received types of errors from an error generation engine storage  124  of the storage module  120 , drive the loaded error generation engine to input errors to the target program, and generate an error program. 
     Also, the error program generator  102  may load the error generation engine corresponding to the received types of errors from the error generation engine storage  124  by referring to an error generation engine mapping table  122 , drive the loaded error generation engine to input errors to the target program, and generate the error program. 
     The error detector  104  executes the test case on the error program output from the error program generator  102  and detects errors. In general, the test case may include a test script for indicating a test procedure, test data required for performing the test script, and a test oracle for determining the presence or absence of an error as a test result. The test oracle is a mechanism or an apparatus for calculating the result of an estimation test performed on the test case or confirming if an actual result is correct. 
     Also, the error detector  104  outputs the number of detected errors and information on the types of errors to the estimation point calculation module  110 . 
     The evaluation point calculation module  110  compares the number of errors input by the error program generator  102  with the number of errors detected by the error detector  104  and calculates evaluation points of the test case. 
     For example, when 10 errors are input by the error program generator  102  and 7 errors are detected by the error detector  104  using a test case A, the test case A has 70 evaluation points (( 7/10)×100=70). 
     Also, the evaluation point calculation module  110  may compare errors input by the error program generator  102  with errors detected by the error detector  104  in consideration of the number of errors, the types of errors, and predetermined weight values for the types of errors and calculates evaluation points of a test case. 
     For example, it is assumed that 5 ambiguity errors and 5 contradiction errors are input by the error program generator  102  to the target program, the weight value of an ambiguity error is 3 and the weight value of a contradiction error is 1. In this case, when 3 ambiguity errors and 2 contradiction errors are detected by the error detector  104  using a test case B, the test case B has 55 evaluation points ((3×3+2×1)/(5×3+5×1)×100=55). 
     The storage module  120  includes the error generation engine mapping table  122  and the error generation engine storage  124 . 
     The error generation engine mapping table  122  registers information on the error generation engine stored in the error generation engine storage  124 . The information on the error generation engine includes information on the types of errors generated by the error generation engine, information on a position where the error generation engine is stored, information on an execution file name of the error generation engine, and information on programming languages used in generating the error generation engine. 
     The error generation engine storage  124  stores the error generation engine for generating errors to be input to the target program. 
       FIG. 2  is a flowchart illustrating a method for evaluating the effectiveness of a test case according to an exemplary embodiment of the present invention. Hereinafter, a method for evaluating the effectiveness of a test case will be described in more detail with reference to  FIGS. 1 and 2 . 
     In step  200 , the error program generator  102  receives a target program and the types of errors to be input to the target program and proceeds to the step  202 . 
     In step  202 , the error program generator  102  searches information on an error generation engine corresponding to the received types of the errors from the error generation engine mapping table  122  and proceeds to the step  204 . 
     In step  204 , the error program generator  102  loads the error generation engine corresponding to the received types of the errors from the error generation engine storage  124  based on the information on the error generation engine registered in the error generation engine mapping table  122 , and proceeds to the step  206 . 
     In step  206 , the error program generator  102  determines the position and number of the errors to be input to the target program and enters step  208 . In this case, a user may input the number of the errors to be input to the target program, and the error program generator  102  may search the target program and determine a block to which the received types of the errors can be applied. That is, since the ambiguity error or contradiction error shown in Tables 1 and 2 occur in conditional sentences, the error program generator  102  searches the position of a conditional sentence from the target program and determines the position where the errors will be input. 
     In step  208 , the error program generator  102  drives the error generation engine loaded in step  204 , inputs the errors to the target program, generates an error program, and outputs the generated error program to the error detector  104 . 
     In step  210 , the error detector  104  executes a test case on the error program output from the error program generator  102 , detects errors, and outputs information on the detected errors to the evaluation point calculation module  110 . In this case, a single test case or a plurality of test cases may be executed. Also, a test case set including a plurality of similar test cases for performing various tests may be executed on a single program. For example, the test case set may include several test cases for performing various tests in an equal usable environment, such as test cases for testing a device driver embedded in a portable terminal according to the usable environment of the device driver. When the error detector  104  executes a test case set in step  210 , a block in which an error is detected by any one test case of the test case set may be skipped during execution of the remaining test cases. As a result, it is possible to reduce a time required for evaluating the effectiveness of the test case set. 
     In step  212 , the evaluation point calculation module  110  calculates evaluation points of the test case based on the information on the detected errors output from the error detector  104  and information on errors received by the error program generator  102 . That is, the evaluation point calculation module  110  compares the number of the errors input by the error program generator  102  with the number of the errors detected by the error detector  104  and calculates the evaluation points of the test case. Also, the evaluation point calculation module  110  may compare the errors input by the error program generator  102  with the errors detected by the error detector  104  in consideration of the number of the errors, the types of the errors, and predetermined weight values for the types of errors, and calculate the evaluation points of the test case. When the test case set is executed in step  210 , the evaluation point calculation module  110  may calculate evaluation points of the entire test case set. 
     As described above, the present invention provides a method and apparatus for evaluating the error detection capability of a test case used for a program test. Also, the capability of the test case to detect errors that are expected to be frequent according to the usable environment of a program is evaluated, thus enabling development of more stable programs. 
     In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation. As for the scope of the invention, it is to be set forth in the following claims. Therefore, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.