How to unit test a Decision Tree rule with the Run Rule feature

The Run Rule feature enables you to test a decision tree rule individually before testing it in the context of the application you are developing. You specify a test page for the rule to use, provide sample data as the input, run the rule, and examine the results. Additionally, if Automated Testing is enabled, you can save the test data and its results as a test case rule.

Before you begin

Before you begin, determine how you will provide the sample data to use when testing the rule. Can you provide all the data directly in the Run Rule window? Or does the rule need specific pages to be on the clipboard to return a decision?

• Examine the rule. Review the Applies To key part, Table tab and Pages & Classes tab of the rule, to identify the classes of the pages it uses for input and the properties involved in the decision.
• The Run Rule feature can create or copy a page to use as the test page, as appropriate for the rule you are testing. The page class of the test page is the Applies To class of the rule. If necessary, you can create a model to set initial values for the page.
• If the rule requires input from several pages, determine how to mimic the processing that creates them so the clipboard has the initial context you need to run the rule. For example, you can run an activity that creates the pages or start a flow and stop it at the appropriate point.

For general information about the Run Rule feature, including a list of the clipboard pages that are generated when a rule runs, see How to test a rule with the Run Rule feature.

Run the rule

To run the rule, complete the following steps:

1. Save the rule.
2. Complete any preprocessing necessary to create the appropriate clipboard context and, if the rule is circumstanced or time-qualified, to set the conditions you want to test.
3. Click the Run toolbar button . The Run Rule window appears.
4. In the Test Page section, specify which page to use as the main page. Do one of the following:
5. • select Create or Reset Test page. Then, in the Apply field, select the model to use for the test page.
     • In the lower section of the Run Rule window, enter the test data and click
        Run Again. The system runs the decision tree rule and displays the results.
   • • Click Run Rule Again as necessary, selecting other model rules or providing other input values.
   • If automated testing is enabled, select Run Against a Saved Test Case. Then choose an individual test case or all test cases from the drop-down list.
     • If Automated Testing is enabled, you can click the
        Save as Test Case   button to create a test case rule that holds the test data and the results. For information about running test cases, see the Pega Developer Network article PRKB-25096 How to create and execute test cases for decision tree and decision table rules.
6. Optional. Click the Result Decision Paths link to go directly to the row on the Decision tab that produced the test result.
7. Optional. Click  Show Clipboard   to open the Clipboard and examine the pages. Click the  Hide Clipboard   button to close the tool. For information about the clipboard pages that are generated, see How to test a rule with the Run Rule feature.

Debugging decision tree rules with the Tracer

If your decision tree rule does not give you the results you expect and you cannot determine the problem by running the rule and examining the clipboard pages, run the Tracer tool. With the Tracer you can watch each step in the evaluation of a decision tree rule as it occurs.

Complete the following steps:

1. From then menu, select the Run > Tracer.
2. In the Tracer window, click the Options button ().
3. In the Event Types to Trace section, select Decision Tree.
4. Select the RuleSet that contains the rule to be traced.
5. Click  OK  .
6. Return to the main portal and run the decision tree rule.
7. Watch the Tracer output as the rule runs.

About Decision Tree rules