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| 1 | +Cucumber Java8 |
| 2 | +============== |
| 3 | + |
| 4 | +Provides lambda based step definitions. To use add the `cucumber-java8` dependency to your pom.xml: |
| 5 | + |
| 6 | +```xml |
| 7 | +<dependencies> |
| 8 | + [...] |
| 9 | + <dependency> |
| 10 | + <groupId>io.cucumber</groupId> |
| 11 | + <artifactId>cucumber-java8</artifactId> |
| 12 | + <version>${cucumber.version}</version> |
| 13 | + <scope>test</scope> |
| 14 | + </dependency> |
| 15 | + [...] |
| 16 | +</dependencies> |
| 17 | +``` |
| 18 | + |
| 19 | +## Step Definitions |
| 20 | + |
| 21 | +Declare a step definition calling a method in the constructor of the glue class. |
| 22 | +For localized methods import the interface from `io.cucumber.java8.<ISO2 Language Code>` |
| 23 | + |
| 24 | +Data tables and Docstrings from Gherkin can be accessed by using a `DataTable` |
| 25 | +or `DocString` object as the last parameter. |
| 26 | + |
| 27 | +```java |
| 28 | +package com.example.app; |
| 29 | + |
| 30 | +import io.cucumber.java8.En; |
| 31 | +import io.cucumber.datatable.DataTable; |
| 32 | +import io.cucumber.docstring.DocString; |
| 33 | + |
| 34 | +import static org.junit.jupiter.api.Assertions.assertEquals; |
| 35 | + |
| 36 | +public class StepDefinitions implements En { |
| 37 | + |
| 38 | + private RpnCalculator calc; |
| 39 | + |
| 40 | + public RpnCalculatorSteps() { |
| 41 | + Given("a calculator I just turned on", () -> { |
| 42 | + calc = new RpnCalculator(); |
| 43 | + }); |
| 44 | + |
| 45 | + When("I add {int} and {int}", (Integer arg1, Integer arg2) -> { |
| 46 | + calc.push(arg1); |
| 47 | + calc.push(arg2); |
| 48 | + calc.push("+"); |
| 49 | + }); |
| 50 | + |
| 51 | + Then("the result is {double}", (Double expected) -> assertEquals(expected, calc.value())); |
| 52 | + |
| 53 | + Given("the previous entries:", (DataTable dataTable) -> { |
| 54 | + List<Entry> entries = dataTable.asList(Entry.class); |
| 55 | + ... |
| 56 | + }); |
| 57 | + |
| 58 | + Then("the calculation log displays:", (DocString docString) -> { |
| 59 | + ... |
| 60 | + }); |
| 61 | + } |
| 62 | +} |
| 63 | +``` |
| 64 | + |
| 65 | +## Hooks |
| 66 | + |
| 67 | +Declare hooks that will be executed before/after each scenario/step by calling a |
| 68 | +method in the constructor. The method may declare an argument of type `io.cucumber.java8.Scenario`. |
| 69 | + |
| 70 | + * `Before` |
| 71 | + * `After` |
| 72 | + * `BeforeStep` |
| 73 | + * `AfterStep` |
| 74 | + |
| 75 | +## Transformers |
| 76 | + |
| 77 | +### Parameter Type |
| 78 | + |
| 79 | +Step definition parameter types can be declared by using `ParameterType`. |
| 80 | + |
| 81 | +```java |
| 82 | +package com.example.app; |
| 83 | + |
| 84 | +import io.cucumber.java8.En; |
| 85 | + |
| 86 | +import static org.junit.jupiter.api.Assertions.assertEquals; |
| 87 | + |
| 88 | +public class StepDefinitions implements En { |
| 89 | + |
| 90 | + public StepDefinitions() { |
| 91 | + ParameterType("amount", "(\\d+\\.\\d+)\\s([a-zA-Z]+)", (String[] values) -> |
| 92 | + new Amount(new BigDecimal(values[0]), Currency.getInstance(values[1]))); |
| 93 | + } |
| 94 | +} |
| 95 | +``` |
| 96 | + |
| 97 | +### Data Table Type |
| 98 | + |
| 99 | +Data table types can be declared by calling `DataTableType` in the constructor. |
| 100 | +Depending on the lambda type this will be either a: |
| 101 | + * `String` -> `io.cucumber.datatable.TableCellTranformer` |
| 102 | + * `Map<String,String>` -> `io.cucumber.datatable.TableEntry` |
| 103 | + * `List<String>` -> `io.cucumber.datatable.TableRow` |
| 104 | + * `DataTable` -> `io.cucumber.datatable.TableTransformer` |
| 105 | + |
| 106 | +```java |
| 107 | +package com.example.app; |
| 108 | + |
| 109 | +import io.cucumber.java8.En; |
| 110 | + |
| 111 | +import java.util.Map; |
| 112 | + |
| 113 | +import static org.junit.jupiter.api.Assertions.assertEquals; |
| 114 | + |
| 115 | +public class StepDefinitions implements En { |
| 116 | + |
| 117 | + public StepDefinitions() { |
| 118 | + DataTableType((Map<String, String> row) -> new Grocery( |
| 119 | + row.get("name"), |
| 120 | + Price.fromString(row.get("price")) |
| 121 | + )); |
| 122 | + } |
| 123 | +} |
| 124 | +``` |
| 125 | + |
| 126 | +### Default Transformers |
| 127 | + |
| 128 | +Default transformers allow you to specific a transformer that will be used when |
| 129 | +there is no transform defined. This can be combined with an object mapper like |
| 130 | +Jackson to quickly transform well known string representations to Java objects. |
| 131 | + |
| 132 | + * `DefaultParameterTransformer` |
| 133 | + * `DefaultDataTableEntryTransformer` |
| 134 | + * `DefaultDataTableCellTransformer` |
| 135 | + |
| 136 | +For a full list of transformations that can be achieved with data table types |
| 137 | +see [cucumber/datatable](https://github.com/cucumber/cucumber/tree/master/datatable) |
| 138 | + |
| 139 | +```java |
| 140 | +package com.example.app; |
| 141 | + |
| 142 | +import com.fasterxml.jackson.databind.ObjectMapper; |
| 143 | + |
| 144 | +import io.cucumber.java8.En; |
| 145 | + |
| 146 | +public class StepDefinitions implements En { |
| 147 | + |
| 148 | + public StepDefinitions() { |
| 149 | + final ObjectMapper objectMapper = new ObjectMapper(); |
| 150 | + |
| 151 | + DefaultParameterTransformer((fromValue, toValueType) -> |
| 152 | + objectMapper.convertValue(fromValue, objectMapper.constructType(toValueType)) |
| 153 | + ); |
| 154 | + } |
| 155 | +} |
| 156 | +``` |
| 157 | + |
| 158 | +### Empty Cells |
| 159 | + |
| 160 | +Data tables in Gherkin can not represent null or the empty string unambiguously. |
| 161 | +Cucumber will interpret empty cells as `null`. |
| 162 | + |
| 163 | +Empty string be represented using a replacement. For example `[empty]`. |
| 164 | +The replacement can be configured providing the `replaceWithEmptyString` |
| 165 | +argument of `DataTableType`, `DefaultDataTableCellTransformer` and |
| 166 | +`DefaultDataTableEntryTransformer`. By default no replacement is configured. |
| 167 | + |
| 168 | +```gherkin |
| 169 | +Given some authors |
| 170 | + | name | first publication | |
| 171 | + | Aspiring Author | | |
| 172 | + | Ancient Author | [blank] | |
| 173 | +``` |
| 174 | + |
| 175 | +```java |
| 176 | +package com.example.app; |
| 177 | + |
| 178 | +import io.cucumber.datatable.DataTable; |
| 179 | + |
| 180 | +import io.cucumber.java8.En; |
| 181 | + |
| 182 | +import java.util.List; |
| 183 | +import java.util.Map; |
| 184 | +import java.util.Optional; |
| 185 | + |
| 186 | +import static org.junit.jupiter.api.Assertions.assertEquals; |
| 187 | +import static org.junit.jupiter.api.Assertions.assertNotSame; |
| 188 | +import static org.junit.jupiter.api.Assertions.assertSame; |
| 189 | +import static org.junit.jupiter.api.Assertions.assertTrue; |
| 190 | + |
| 191 | +public class StepDefinitions implements En { |
| 192 | + |
| 193 | + public StepDefinitions() { |
| 194 | + DataTableType("[blank]", (Map<String, String> entry) -> new Author( |
| 195 | + entry.get("name"), |
| 196 | + entry.get("first publication") |
| 197 | + )); |
| 198 | + |
| 199 | + Given("some authors", (DataTable authorsTable) -> { |
| 200 | + List<Author> authors = authorsTable.asList(Author.class); |
| 201 | + // authors = [Author(name="Aspiring Author", firstPublication=null), Author(name="Ancient Author", firstPublication=)] |
| 202 | + |
| 203 | + }); |
| 204 | + } |
| 205 | +} |
| 206 | +``` |
| 207 | + |
| 208 | +# Transposing Tables |
| 209 | + |
| 210 | +A data table can be transposed by calling `.transpose()`. This means the keys |
| 211 | +will be in the first column rather then the first row. |
| 212 | + |
| 213 | +```gherkin |
| 214 | + Given the user is |
| 215 | + | firstname | Roberto | |
| 216 | + | lastname | Lo Giacco | |
| 217 | + | nationality | Italian | |
| 218 | + ``` |
| 219 | + |
| 220 | +And a data table type to create a User |
| 221 | + |
| 222 | +```java |
| 223 | +package com.example.app; |
| 224 | + |
| 225 | +import io.cucumber.datatable.DataTable; |
| 226 | + |
| 227 | +import io.cucumber.java8.En; |
| 228 | + |
| 229 | +import java.util.List; |
| 230 | +import java.util.Map; |
| 231 | +import java.util.Optional; |
| 232 | + |
| 233 | +import static org.junit.jupiter.api.Assertions.assertEquals; |
| 234 | +import static org.junit.jupiter.api.Assertions.assertNotSame; |
| 235 | +import static org.junit.jupiter.api.Assertions.assertSame; |
| 236 | +import static org.junit.jupiter.api.Assertions.assertTrue; |
| 237 | + |
| 238 | +public class StepDefinitions implements En { |
| 239 | + |
| 240 | + public StepDefinitions() { |
| 241 | + DataTableType((Map<String, String> entry) -> new User( |
| 242 | + entry.get("firstname"), |
| 243 | + entry.get("lastname") |
| 244 | + entry.get("nationality") |
| 245 | + )); |
| 246 | + |
| 247 | + Given("the user is", (DataTable authorsTable) -> { |
| 248 | + User user = authorsTable.transpose().asList(User.class); |
| 249 | + // user = User(firstname="Roberto", lastname="Lo Giacco", nationality="Italian") |
| 250 | + }); |
| 251 | + } |
| 252 | +} |
| 253 | +``` |
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