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Common Test
Reference Manual
Version 1.12.2


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common_test

MODULE

common_test

MODULE SUMMARY

A framework for automated testing of any target nodes.

DESCRIPTION

The Common Test framework is an environment for implementing and performing automatic and semi-automatic execution of test cases.

In brief, Common Test supports:

  • Automated execution of test suites (sets of test cases)
  • Logging of events during execution
  • HTML presentation of test suite results
  • HTML presentation of test suite code
  • Support functions for test suite authors
  • Step-by-step execution of test cases

The following section describes the mandatory and optional test suite functions that Common Test calls during test execution. For more details, see section Writing Test Suites in the User's Guide.

Test Case Callback Functions

The following functions define the callback interface for a test suite.

EXPORTS

Module:all() -> Tests | {skip,Reason}

Types:

Tests = [TestCase | {group,GroupName} | {group,GroupName,Properties} | {group,GroupName,Properties,SubGroups}]
TestCase = atom()
GroupName = atom()
Properties = [parallel | sequence | Shuffle | {RepeatType,N}] | default
SubGroups = [{GroupName,Properties} | {GroupName,Properties,SubGroups}]
Shuffle = shuffle | {shuffle,Seed}
Seed = {integer(),integer(),integer()}
RepeatType = repeat | repeat_until_all_ok | repeat_until_all_fail | repeat_until_any_ok | repeat_until_any_fail
N = integer() | forever
Reason = term()

MANDATORY

Returns the list of all test cases and test case groups in the test suite module to be executed. This list also specifies the order the cases and groups are executed by Common Test. A test case is represented by an atom, the name of the test case function. A test case group is represented by a group tuple, where GroupName, an atom, is the name of the group (defined in groups/0). Execution properties for groups can also be specified, both for a top-level group and for any of its subgroups. Group execution properties specified here override properties in the group definition (see groups/0). (With value default, the group definition properties are used).

If {skip,Reason} is returned, all test cases in the module are skipped and Reason is printed on the HTML result page.

For details on groups, see section Test Case Groups in the User's Guide.

Module:groups() -> GroupDefs

Types:

GroupDefs = [Group]
Group = {GroupName,Properties,GroupsAndTestCases}
GroupName = atom()
Properties = [parallel | sequence | Shuffle | {RepeatType,N}]
GroupsAndTestCases = [Group | {group,GroupName} | TestCase]
TestCase = atom()
Shuffle = shuffle | {shuffle,Seed}
Seed = {integer(),integer(),integer()}
RepeatType = repeat | repeat_until_all_ok | repeat_until_all_fail | repeat_until_any_ok | repeat_until_any_fail
N = integer() | forever

OPTIONAL

Defines test case groups. For details, see section Test Case Groups in the User's Guide.

Module:suite() -> [Info]

Types:

Info = {timetrap,Time} | {require,Required} | {require,Name,Required} | {userdata,UserData} | {silent_connections,Conns} | {stylesheet,CSSFile} | {ct_hooks, CTHs}
Time = TimeVal | TimeFunc
TimeVal = MilliSec | {seconds,integer()} | {minutes,integer()} | {hours,integer()}
TimeFunc = {Mod,Func,Args} | Fun
MilliSec = integer()
Mod = atom()
Func = atom()
Args = list()
Fun = fun()
Required = Key | {Key,SubKeys} | {Key,SubKey} | {Key,SubKey,SubKeys}
Key = atom()
SubKeys = SubKey | [SubKey]
SubKey = atom()
Name = atom()
UserData = term()
Conns = [atom()]
CSSFile = string()
CTHs = [CTHModule |
        {CTHModule, CTHInitArgs} |
        {CTHModule, CTHInitArgs, CTHPriority}]
CTHModule = atom()
CTHInitArgs = term()

OPTIONAL

The test suite information function. Returns a list of tagged tuples specifying various properties related to the execution of this test suite (common for all test cases in the suite).

Tag timetrap sets the maximum time that each test case is allowed to execute (including init_per_testcase/2 and end_per_testcase/2). If the timetrap time is exceeded, the test case fails with reason timetrap_timeout. A TimeFunc function can be used to set a new timetrap by returning a TimeVal. It can also be used to trigger a timetrap time-out by, at some point, returning a value other than a TimeVal. For details, see section Timetrap Time-Outs in the User's Guide.

Tag require specifies configuration variables required by test cases (or configuration functions) in the suite. If the required configuration variables are not found in any of the configuration files, all test cases are skipped. For details about the require functionality, see funtion ct:require/1,2.

With userdata, the user can specify any test suite-related information, which can be read by calling ct:userdata/2.

Tag ct_hooks specifies the Common Test Hooks to be run with this suite.

Other tuples than the ones defined are ignored.

For details about the test suite information function, see section Test Suite Information Function in the User's Guide.

Module:init_per_suite(Config) -> NewConfig | {skip,Reason} | {skip_and_save,Reason,SaveConfig}

Types:

Config = NewConfig = SaveConfig = [{Key,Value}]
Key = atom()
Value = term()
Reason = term()

OPTIONAL

This configuration function is called as the first function in the suite. It typically contains initializations that are common for all test cases in the suite, and that must only be done once. Parameter Config is the configuration data that can be modified. Whatever is returned from this function is specified as Config to all configuration functions and test cases in the suite.

If {skip,Reason} is returned, all test cases in the suite are skipped and Reason is printed in the overview log for the suite.

For information on save_config and skip_and_save, see section Saving Configuration Data in the User's Guide.

Module:end_per_suite(Config) -> term() | {save_config,SaveConfig}

Types:

Config = SaveConfig = [{Key,Value}]
Key = atom()
Value = term()

OPTIONAL

This function is called as the last test case in the suite. It is meant to be used for cleaning up after init_per_suite/1.

For information on save_config, see section Saving Configuration Data in the User's Guide.

Module:group(GroupName) -> [Info]

Types:

Info = {timetrap,Time} | {require,Required} | {require,Name,Required} | {userdata,UserData} | {silent_connections,Conns} | {stylesheet,CSSFile} | {ct_hooks, CTHs}
Time = TimeVal | TimeFunc
TimeVal = MilliSec | {seconds,integer()} | {minutes,integer()} | {hours,integer()}
TimeFunc = {Mod,Func,Args} | Fun
MilliSec = integer()
Mod = atom()
Func = atom()
Args = list()
Fun = fun()
Required = Key | {Key,SubKeys} | {Key,Subkey} | {Key,Subkey,SubKeys}
Key = atom()
SubKeys = SubKey | [SubKey]
SubKey = atom()
Name = atom()
UserData = term()
Conns = [atom()]
CSSFile = string()
CTHs = [CTHModule |
        {CTHModule, CTHInitArgs} |
        {CTHModule, CTHInitArgs, CTHPriority}]
CTHModule = atom()
CTHInitArgs = term()

OPTIONAL

The test case group information function. It is supposed to return a list of tagged tuples that specify various properties related to the execution of a test case group (that is, its test cases and subgroups). Properties set by group/1 override properties with the same key that have been set previously by suite/0.

Tag timetrap sets the maximum time that each test case is allowed to execute (including init_per_testcase/2 and end_per_testcase/2). If the timetrap time is exceeded, the test case fails with reason timetrap_timeout. A TimeFunc function can be used to set a new timetrap by returning a TimeVal. It can also be used to trigger a timetrap time-out by, at some point, returning a value other than a TimeVal. For details, see section Timetrap Time-Outs in the User's Guide.

Tag require specifies configuration variables required by test cases (or configuration functions) in the suite. If the required configuration variables are not found in any of the configuration files, all test cases in this group are skipped. For details about the require functionality, see function ct:require/1,2.

With userdata, the user can specify any test case group related information that can be read by calling ct:userdata/2.

Tag ct_hooks specifies the Common Test Hooks to be run with this suite.

Other tuples than the ones defined are ignored.

For details about the test case group information function, see section Group Information Function in the User's Guide.

Module:init_per_group(GroupName, Config) -> NewConfig | {skip,Reason}

Types:

GroupName = atom()
Config = NewConfig = [{Key,Value}]
Key = atom()
Value = term()
Reason = term()

OPTIONAL

This configuration function is called before execution of a test case group. It typically contains initializations that are common for all test cases and subgroups in the group, and that must only be performed once. GroupName is the name of the group, as specified in the group definition (see groups/0). Parameter Config is the configuration data that can be modified. The return value of this function is given as Config to all test cases and subgroups in the group.

If {skip,Reason} is returned, all test cases in the group are skipped and Reason is printed in the overview log for the group.

For information about test case groups, see section Test Case Groups in the User's Guide.

Module:end_per_group(GroupName, Config) -> term() | {return_group_result,Status}

Types:

GroupName = atom()
Config = [{Key,Value}]
Key = atom()
Value = term()
Status = ok | skipped | failed

OPTIONAL

This function is called after the execution of a test case group is finished. It is meant to be used for cleaning up after init_per_group/2. A status value for a nested subgroup can be returned with {return_group_result,Status}. The status can be retrieved in end_per_group/2 for the group on the level above. The status is also used by Common Test for deciding if execution of a group is to proceed if property sequence or repeat_until_* is set.

For details about test case groups, see section Test Case Groups in the User's Guide.

Module:init_per_testcase(TestCase, Config) -> NewConfig | {fail,Reason} | {skip,Reason}

Types:

TestCase = atom()
Config = NewConfig = [{Key,Value}]
Key = atom()
Value = term()
Reason = term()

OPTIONAL

This function is called before each test case. Argument TestCase is the test case name, and Config (list of key-value tuples) is the configuration data that can be modified. The NewConfig list returned from this function is given as Config to the test case. If {fail,Reason} is returned, the test case is marked as failed without being executed.

If {skip,Reason} is returned, the test case is skipped and Reason is printed in the overview log for the suite.

Module:end_per_testcase(TestCase, Config) -> term() | {fail,Reason} | {save_config,SaveConfig}

Types:

TestCase = atom()
Config = SaveConfig = [{Key,Value}]
Key = atom()
Value = term()
Reason = term()

OPTIONAL

This function is called after each test case, and can be used to clean up after init_per_testcase/2 and the test case. Any return value (besides {fail,Reason} and {save_config,SaveConfig}) is ignored. By returning {fail,Reason}, TestCase is marked as faulty (even though it was successful in the sense that it returned a value instead of terminating).

For information on save_config, see section Saving Configuration Data in the User's Guide.

Module:Testcase() -> [Info]

Types:

Info = {timetrap,Time} | {require,Required} | {require,Name,Required} | {userdata,UserData} | {silent_connections,Conns}
Time = TimeVal | TimeFunc
TimeVal = MilliSec | {seconds,integer()} | {minutes,integer()} | {hours,integer()}
TimeFunc = {Mod,Func,Args} | Fun
MilliSec = integer()
Mod = atom()
Func = atom()
Args = list()
Fun = fun()
Required = Key | {Key,SubKeys} | {Key,Subkey} | {Key,Subkey,SubKeys}
Key = atom()
SubKeys = SubKey | [SubKey]
SubKey = atom()
Name = atom()
UserData = term()
Conns = [atom()]

OPTIONAL

The test case information function. It is supposed to return a list of tagged tuples that specify various properties related to the execution of this particular test case. Properties set by Testcase/0 override properties set previously for the test case by group/1 or suite/0.

Tag timetrap sets the maximum time that the test case is allowed to execute. If the timetrap time is exceeded, the test case fails with reason timetrap_timeout. init_per_testcase/2 and end_per_testcase/2 are included in the timetrap time. A TimeFunc function can be used to set a new timetrap by returning a TimeVal. It can also be used to trigger a timetrap time-out by, at some point, returning a value other than a TimeVal. For details, see section Timetrap Time-Outs in the User's Guide.

Tag require specifies configuration variables that are required by the test case (or init_per_testcase/2 or end_per_testcase/2). If the required configuration variables are not found in any of the configuration files, the test case is skipped. For details about the require functionality, see function ct:require/1,2.

If timetrap or require is not set, the default values specified by suite/0 (or group/1) are used.

With userdata, the user can specify any test case-related information that can be read by calling ct:userdata/3.

Other tuples than the ones defined are ignored.

For details about the test case information function, see section Test Case Information Function in the User's Guide.

Module:Testcase(Config) -> term() | {skip,Reason} | {comment,Comment} | {save_config,SaveConfig} | {skip_and_save,Reason,SaveConfig} | exit()

Types:

Config = SaveConfig = [{Key,Value}]
Key = atom()
Value = term()
Reason = term()
Comment = string()

MANDATORY

The implementation of a test case. Call the functions to test and check the result. If something fails, ensure the function causes a runtime error or call ct:fail/1,2 (which also causes the test case process to terminate).

Elements from the Config list can, for example, be read with proplists:get_value/2 in STDLIB (or the macro ?config defined in ct.hrl).

If you decide not to run the test case after all, return {skip,Reason}. Reason is then printed in field Comment on the HTML result page.

To print some information in field Comment on the HTML result page, return {comment,Comment}.

If the function returns anything else, the test case is considered successful. The return value always gets printed in the test case log file.

For details about test case implementation, see section Test Cases in the User's Guide.

For information on save_config and skip_and_save, see section Saving Configuration Data in the User's Guide.

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