How to use external data file (for example a json file) for scenario outline for iterate over a scenario

Question

How to use external data file (for example a json file) for scenario outline to iterate over a scenario in CucumberJS

Answer 1

You need use a custom code to inject the data in Examples of Scenario Outline. NoraUi automation Framework use this technic.

Example of scenario:

@loginLogout
Feature: loginLogout (Scenario that login and logout with any good user.) 

    Scenario Outline:  Scenario that login and logout with any good user.

    Given I check that 'user' '<user>' is not empty
    Given I check that 'user' '<password>' is not empty

    Given 'BAKERY_HOME' is opened
    Then The BAKERY home page is displayed

    When I log in to BAKERY as '<user>' '<password>'
    Then The administrator part of the BAKERY portal is displayed?
        |key|expected|actual|
        |profile|admin|<profile>|
    Then The referencer part of the BAKERY portal is displayed?
        |key|expected|actual|
        |profile|referencer|<profile>|    

    And I wait 3 seconds

    When I log out of BAKERY
    Then The BAKERY logout page is displayed

    And I go back to 'BAKERY_HOME'

    Examples:
    #DATA
    |id|user|password|profile|
    |1|foo|123456|admin|
    |2|bar|123456|referencer|
    #END

Exemple of injector in java, you need use the same technic with your favorite languge:

public static void injectDataInGherkinExamples(String filename, Map<Integer, List<String[]>> examplesTable) {
    try {
        if (!examplesTable.isEmpty()) {
            final Path filePath = getFeaturePath(filename);
            final String fileContent = new String(Files.readAllBytes(filePath), Constants.DEFAULT_ENDODING);
            String lang = getFeatureLanguage(fileContent);
            LOGGER.info(lang);
            StringBuilder examplesString;
            final String[] scenarioOutlines = "fr".equals(lang) ? fileContent.split(SCENARIO_OUTLINE_SPLIT_FR) : fileContent.split(SCENARIO_OUTLINE_SPLIT);
            for (final Entry<Integer, List<String[]>> examples : examplesTable.entrySet()) {
                examplesString = new StringBuilder();
                examplesString.append("    ");
                for (int j = 0; j < examples.getValue().size(); j++) {
                    examplesString.append(SCENARIO_EXAMPLE_COLUMNS_SEPARATOR);
                    examplesString.append(j + 1);
                    for (final String col : examples.getValue().get(j)) {
                        examplesString.append(SCENARIO_EXAMPLE_COLUMNS_SEPARATOR);
                        examplesString.append(col);
                    }
                    examplesString.append(SCENARIO_EXAMPLE_COLUMNS_SEPARATOR + "\n    ");
                }

                scenarioOutlines[examples.getKey() + 1] = scenarioOutlines[examples.getKey() + 1].replaceAll("(" + DATA + "\r?\n.*\r?\n)[\\s\\S]*(" + DATA_END + ")",
                        "$1" + examplesString.toString() + "$2");
            }

            try (BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(filePath.toString()), Constants.DEFAULT_ENDODING));) {
                int i = 0;
                bw.write(scenarioOutlines[i]);

                while (++i < scenarioOutlines.length) {
                    if ("fr".equals(lang)) {
                        bw.write(SCENARIO_OUTLINE_SPLIT_FR + scenarioOutlines[i]);
                    } else {
                        bw.write(SCENARIO_OUTLINE_SPLIT + scenarioOutlines[i]);
                    }
                }
            }
        }
    } catch (final IOException e) {
        LOGGER.error("error GherkinFactory.injectDataInGherkinExamples()", e);
    }
}

you can find all source here on github.